Commit Graph

18785 Commits

Author SHA1 Message Date
NARIBAYASHI Akira 0fc9ba59eb mm, compaction: fix fast_isolate_around() to stay within boundaries
commit be21b32afe upstream.

Depending on the memory configuration, isolate_freepages_block() may scan
pages out of the target range and causes panic.

Panic can occur on systems with multiple zones in a single pageblock.

The reason it is rare is that it only happens in special
configurations.  Depending on how many similar systems there are, it
may be a good idea to fix this problem for older kernels as well.

The problem is that pfn as argument of fast_isolate_around() could be out
of the target range.  Therefore we should consider the case where pfn <
start_pfn, and also the case where end_pfn < pfn.

This problem should have been addressd by the commit 6e2b7044c1 ("mm,
compaction: make fast_isolate_freepages() stay within zone") but there was
an oversight.

 Case1: pfn < start_pfn

  <at memory compaction for node Y>
  |  node X's zone  | node Y's zone
  +-----------------+------------------------------...
   pageblock    ^   ^     ^
  +-----------+-----------+-----------+-----------+...
                ^   ^     ^
                ^   ^      end_pfn
                ^    start_pfn = cc->zone->zone_start_pfn
                 pfn
                <---------> scanned range by "Scan After"

 Case2: end_pfn < pfn

  <at memory compaction for node X>
  |  node X's zone  | node Y's zone
  +-----------------+------------------------------...
   pageblock  ^     ^   ^
  +-----------+-----------+-----------+-----------+...
              ^     ^   ^
              ^     ^    pfn
              ^      end_pfn
               start_pfn
              <---------> scanned range by "Scan Before"

It seems that there is no good reason to skip nr_isolated pages just after
given pfn.  So let perform simple scan from start to end instead of
dividing the scan into "Before" and "After".

Link: https://lkml.kernel.org/r/20221026112438.236336-1-a.naribayashi@fujitsu.com
Fixes: 6e2b7044c1 ("mm, compaction: make fast_isolate_freepages() stay within zone").
Signed-off-by: NARIBAYASHI Akira <a.naribayashi@fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-04 11:26:30 +01:00
Mathieu Desnoyers 4ca0eb6b2f mm/mempolicy: fix memory leak in set_mempolicy_home_node system call
commit 38ce7c9bdf upstream.

When encountering any vma in the range with policy other than MPOL_BIND or
MPOL_PREFERRED_MANY, an error is returned without issuing a mpol_put on
the policy just allocated with mpol_dup().

This allows arbitrary users to leak kernel memory.

Link: https://lkml.kernel.org/r/20221215194621.202816-1-mathieu.desnoyers@efficios.com
Fixes: c6018b4b25 ("mm/mempolicy: add set_mempolicy_home_node syscall")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: <stable@vger.kernel.org>	[5.17+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-04 11:26:28 +01:00
David Hildenbrand 9b34db7f86 mm/gup: disallow FOLL_FORCE|FOLL_WRITE on hugetlb mappings
commit f347454d03 upstream.

hugetlb does not support fake write-faults (write faults without write
permissions).  However, we are currently able to trigger a
FAULT_FLAG_WRITE fault on a VMA without VM_WRITE.

If we'd ever want to support FOLL_FORCE|FOLL_WRITE, we'd have to teach
hugetlb to:

(1) Leave the page mapped R/O after the fake write-fault, like
    maybe_mkwrite() does.
(2) Allow writing to an exclusive anon page that's mapped R/O when
    FOLL_FORCE is set, like can_follow_write_pte(). E.g.,
    __follow_hugetlb_must_fault() needs adjustment.

For now, it's not clear if that added complexity is really required.
History tolds us that FOLL_FORCE is dangerous and that we better limit its
use to a bare minimum.

--------------------------------------------------------------------------
  #include <stdio.h>
  #include <stdlib.h>
  #include <fcntl.h>
  #include <unistd.h>
  #include <errno.h>
  #include <stdint.h>
  #include <sys/mman.h>
  #include <linux/mman.h>

  int main(int argc, char **argv)
  {
          char *map;
          int mem_fd;

          map = mmap(NULL, 2 * 1024 * 1024u, PROT_READ,
                     MAP_PRIVATE|MAP_ANON|MAP_HUGETLB|MAP_HUGE_2MB, -1, 0);
          if (map == MAP_FAILED) {
                  fprintf(stderr, "mmap() failed: %d\n", errno);
                  return 1;
          }

          mem_fd = open("/proc/self/mem", O_RDWR);
          if (mem_fd < 0) {
                  fprintf(stderr, "open(/proc/self/mem) failed: %d\n", errno);
                  return 1;
          }

          if (pwrite(mem_fd, "0", 1, (uintptr_t) map) == 1) {
                  fprintf(stderr, "write() succeeded, which is unexpected\n");
                  return 1;
          }

          printf("write() failed as expected: %d\n", errno);
          return 0;
  }
--------------------------------------------------------------------------

Fortunately, we have a sanity check in hugetlb_wp() in place ever since
commit 1d8d14641f ("mm/hugetlb: support write-faults in shared
mappings"), that bails out instead of silently mapping a page writable in
a !PROT_WRITE VMA.

Consequently, above reproducer triggers a warning, similar to the one
reported by szsbot:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 3612 at mm/hugetlb.c:5313 hugetlb_wp+0x20a/0x1af0 mm/hugetlb.c:5313
Modules linked in:
CPU: 1 PID: 3612 Comm: syz-executor250 Not tainted 6.1.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
RIP: 0010:hugetlb_wp+0x20a/0x1af0 mm/hugetlb.c:5313
Code: ea 03 80 3c 02 00 0f 85 31 14 00 00 49 8b 5f 20 31 ff 48 89 dd 83 e5 02 48 89 ee e8 70 ab b7 ff 48 85 ed 75 5b e8 76 ae b7 ff <0f> 0b 41 bd 40 00 00 00 e8 69 ae b7 ff 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc90003caf620 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000008640070 RCX: 0000000000000000
RDX: ffff88807b963a80 RSI: ffffffff81c4ed2a RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000008c07e R12: ffff888023805800
R13: 0000000000000000 R14: ffffffff91217f38 R15: ffff88801d4b0360
FS:  0000555555bba300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff7a47a1b8 CR3: 000000002378d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 hugetlb_no_page mm/hugetlb.c:5755 [inline]
 hugetlb_fault+0x19cc/0x2060 mm/hugetlb.c:5874
 follow_hugetlb_page+0x3f3/0x1850 mm/hugetlb.c:6301
 __get_user_pages+0x2cb/0xf10 mm/gup.c:1202
 __get_user_pages_locked mm/gup.c:1434 [inline]
 __get_user_pages_remote+0x18f/0x830 mm/gup.c:2187
 get_user_pages_remote+0x84/0xc0 mm/gup.c:2260
 __access_remote_vm+0x287/0x6b0 mm/memory.c:5517
 ptrace_access_vm+0x181/0x1d0 kernel/ptrace.c:61
 generic_ptrace_pokedata kernel/ptrace.c:1323 [inline]
 ptrace_request+0xb46/0x10c0 kernel/ptrace.c:1046
 arch_ptrace+0x36/0x510 arch/x86/kernel/ptrace.c:828
 __do_sys_ptrace kernel/ptrace.c:1296 [inline]
 __se_sys_ptrace kernel/ptrace.c:1269 [inline]
 __x64_sys_ptrace+0x178/0x2a0 kernel/ptrace.c:1269
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]

So let's silence that warning by teaching GUP code that FOLL_FORCE -- so
far -- does not apply to hugetlb.

Note that FOLL_FORCE for read-access seems to be working as expected.  The
assumption is that this has been broken forever, only ever since above
commit, we actually detect the wrong handling and WARN_ON_ONCE().

I assume this has been broken at least since 2014, when mm/gup.c came to
life.  I failed to come up with a suitable Fixes tag quickly.

Link: https://lkml.kernel.org/r/20221031152524.173644-1-david@redhat.com
Fixes: 1d8d14641f ("mm/hugetlb: support write-faults in shared mappings")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: <syzbot+f0b97304ef90f0d0b1dc@syzkaller.appspotmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-31 13:26:53 +01:00
Hugh Dickins 078c091e9a tmpfs: fix data loss from failed fallocate
commit 44bcabd70c upstream.

Fix tmpfs data loss when the fallocate system call is interrupted by a
signal, or fails for some other reason.  The partial folio handling in
shmem_undo_range() forgot to consider this unfalloc case, and was liable
to erase or truncate out data which had already been committed earlier.

It turns out that none of the partial folio handling there is appropriate
for the unfalloc case, which just wants to proceed to removal of whole
folios: which find_get_entries() provides, even when partially covered.

Original patch by Rui Wang.

Link: https://lore.kernel.org/linux-mm/33b85d82.7764.1842e9ab207.Coremail.chenguoqic@163.com/
Link: https://lkml.kernel.org/r/a5dac112-cf4b-7af-a33-f386e347fd38@google.com
Fixes: b9a8a4195c ("truncate,shmem: Handle truncates that split large folios")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Guoqi Chen <chenguoqic@163.com>
  Link: https://lore.kernel.org/all/20221101032248.819360-1-kernel@hev.cc/
Cc: Rui Wang <kernel@hev.cc>
Cc: Huacai Chen <chenhuacai@loongson.cn>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: <stable@vger.kernel.org>	[5.17+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-14 11:40:52 +01:00
John Starks e06d13c36d mm/gup: fix gup_pud_range() for dax
commit fcd0ccd836 upstream.

For dax pud, pud_huge() returns true on x86. So the function works as long
as hugetlb is configured. However, dax doesn't depend on hugetlb.
Commit 414fd080d1 ("mm/gup: fix gup_pmd_range() for dax") fixed
devmap-backed huge PMDs, but missed devmap-backed huge PUDs. Fix this as
well.

This fixes the below kernel panic:

general protection fault, probably for non-canonical address 0x69e7c000cc478: 0000 [#1] SMP
	< snip >
Call Trace:
<TASK>
get_user_pages_fast+0x1f/0x40
iov_iter_get_pages+0xc6/0x3b0
? mempool_alloc+0x5d/0x170
bio_iov_iter_get_pages+0x82/0x4e0
? bvec_alloc+0x91/0xc0
? bio_alloc_bioset+0x19a/0x2a0
blkdev_direct_IO+0x282/0x480
? __io_complete_rw_common+0xc0/0xc0
? filemap_range_has_page+0x82/0xc0
generic_file_direct_write+0x9d/0x1a0
? inode_update_time+0x24/0x30
__generic_file_write_iter+0xbd/0x1e0
blkdev_write_iter+0xb4/0x150
? io_import_iovec+0x8d/0x340
io_write+0xf9/0x300
io_issue_sqe+0x3c3/0x1d30
? sysvec_reschedule_ipi+0x6c/0x80
__io_queue_sqe+0x33/0x240
? fget+0x76/0xa0
io_submit_sqes+0xe6a/0x18d0
? __fget_light+0xd1/0x100
__x64_sys_io_uring_enter+0x199/0x880
? __context_tracking_enter+0x1f/0x70
? irqentry_exit_to_user_mode+0x24/0x30
? irqentry_exit+0x1d/0x30
? __context_tracking_exit+0xe/0x70
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fc97c11a7be
	< snip >
</TASK>
---[ end trace 48b2e0e67debcaeb ]---
RIP: 0010:internal_get_user_pages_fast+0x340/0x990
	< snip >
Kernel panic - not syncing: Fatal exception
Kernel Offset: disabled

Link: https://lkml.kernel.org/r/1670392853-28252-1-git-send-email-ssengar@linux.microsoft.com
Fixes: 414fd080d1 ("mm/gup: fix gup_pmd_range() for dax")
Signed-off-by: John Starks <jostarks@microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-14 11:40:52 +01:00
Tejun Heo 0ed074317b memcg: fix possible use-after-free in memcg_write_event_control()
commit 4a7ba45b1a upstream.

memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call.  As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file.  Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.

Prior to 347c4a8747 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses.  The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently dropped
the file type check with it allowing any file to slip through.  With the
invarients broken, the d_name and parent accesses can now race against
renames and removals of arbitrary files and cause use-after-free's.

Fix the bug by resurrecting the file type check in __file_cft().  Now that
cgroupfs is implemented through kernfs, checking the file operations needs
to go through a layer of indirection.  Instead, let's check the superblock
and dentry type.

Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org
Fixes: 347c4a8747 ("memcg: remove cgroup_event->cft")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>	[3.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-14 11:40:52 +01:00
Mike Kravetz bb8f66f6af hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing
commit 04ada095dc upstream.

madvise(MADV_DONTNEED) ends up calling zap_page_range() to clear page
tables associated with the address range.  For hugetlb vmas,
zap_page_range will call __unmap_hugepage_range_final.  However,
__unmap_hugepage_range_final assumes the passed vma is about to be removed
and deletes the vma_lock to prevent pmd sharing as the vma is on the way
out.  In the case of madvise(MADV_DONTNEED) the vma remains, but the
missing vma_lock prevents pmd sharing and could potentially lead to issues
with truncation/fault races.

This issue was originally reported here [1] as a BUG triggered in
page_try_dup_anon_rmap.  Prior to the introduction of the hugetlb
vma_lock, __unmap_hugepage_range_final cleared the VM_MAYSHARE flag to
prevent pmd sharing.  Subsequent faults on this vma were confused as
VM_MAYSHARE indicates a sharable vma, but was not set so page_mapping was
not set in new pages added to the page table.  This resulted in pages that
appeared anonymous in a VM_SHARED vma and triggered the BUG.

Address issue by adding a new zap flag ZAP_FLAG_UNMAP to indicate an unmap
call from unmap_vmas().  This is used to indicate the 'final' unmapping of
a hugetlb vma.  When called via MADV_DONTNEED, this flag is not set and
the vm_lock is not deleted.

NOTE - Prior to the introduction of the huegtlb vma_lock in v6.1,  this
       issue is addressed by not clearing the VM_MAYSHARE flag when
       __unmap_hugepage_range_final is called in the MADV_DONTNEED case.

[1] https://lore.kernel.org/lkml/CAO4mrfdLMXsao9RF4fUE8-Wfde8xmjsKrTNMNC9wjUb6JudD0g@mail.gmail.com/

Link: https://lkml.kernel.org/r/20221114235507.294320-3-mike.kravetz@oracle.com
Fixes: 90e7e7f5ef ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Wei Chen <harperchen1110@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:40:50 +01:00
Jann Horn 5450535901 mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths
commit f268f6cf87 upstream.

Any codepath that zaps page table entries must invoke MMU notifiers to
ensure that secondary MMUs (like KVM) don't keep accessing pages which
aren't mapped anymore.  Secondary MMUs don't hold their own references to
pages that are mirrored over, so failing to notify them can lead to page
use-after-free.

I'm marking this as addressing an issue introduced in commit f3f0e1d215
("khugepaged: add support of collapse for tmpfs/shmem pages"), but most of
the security impact of this only came in commit 27e1f82731 ("khugepaged:
enable collapse pmd for pte-mapped THP"), which actually omitted flushes
for the removal of present PTEs, not just for the removal of empty page
tables.

Link: https://lkml.kernel.org/r/20221129154730.2274278-3-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-3-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-3-jannh@google.com
Fixes: f3f0e1d215 ("khugepaged: add support of collapse for tmpfs/shmem pages")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[backported, no changes necessary]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:40:50 +01:00
Jann Horn 740f308463 mm/khugepaged: fix GUP-fast interaction by sending IPI
commit 2ba99c5e08 upstream.

Since commit 70cbc3cc78 ("mm: gup: fix the fast GUP race against THP
collapse"), the lockless_pages_from_mm() fastpath rechecks the pmd_t to
ensure that the page table was not removed by khugepaged in between.

However, lockless_pages_from_mm() still requires that the page table is
not concurrently freed.  Fix it by sending IPIs (if the architecture uses
semi-RCU-style page table freeing) before freeing/reusing page tables.

Link: https://lkml.kernel.org/r/20221129154730.2274278-2-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-2-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-2-jannh@google.com
Fixes: ba76149f47 ("thp: khugepaged")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[backported, no changes necessary]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:40:50 +01:00
Jann Horn 97d3a58bc9 mm/khugepaged: take the right locks for page table retraction
commit 8d3c106e19 upstream.

pagetable walks on address ranges mapped by VMAs can be done under the
mmap lock, the lock of an anon_vma attached to the VMA, or the lock of the
VMA's address_space.  Only one of these needs to be held, and it does not
need to be held in exclusive mode.

Under those circumstances, the rules for concurrent access to page table
entries are:

 - Terminal page table entries (entries that don't point to another page
   table) can be arbitrarily changed under the page table lock, with the
   exception that they always need to be consistent for
   hardware page table walks and lockless_pages_from_mm().
   This includes that they can be changed into non-terminal entries.
 - Non-terminal page table entries (which point to another page table)
   can not be modified; readers are allowed to READ_ONCE() an entry, verify
   that it is non-terminal, and then assume that its value will stay as-is.

Retracting a page table involves modifying a non-terminal entry, so
page-table-level locks are insufficient to protect against concurrent page
table traversal; it requires taking all the higher-level locks under which
it is possible to start a page walk in the relevant range in exclusive
mode.

The collapse_huge_page() path for anonymous THP already follows this rule,
but the shmem/file THP path was getting it wrong, making it possible for
concurrent rmap-based operations to cause corruption.

Link: https://lkml.kernel.org/r/20221129154730.2274278-1-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-1-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-1-jannh@google.com
Fixes: 27e1f82731 ("khugepaged: enable collapse pmd for pte-mapped THP")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[backport fixed up manually: collapse_pte_mapped_thp returns different
type]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:40:49 +01:00
Mike Kravetz e61e16403b madvise: use zap_page_range_single for madvise dontneed
[ Upstream commit 21b85b0952 ]

This series addresses the issue first reported in [1], and fully described
in patch 2.  Patches 1 and 2 address the user visible issue and are tagged
for stable backports.

While exploring solutions to this issue, related problems with mmu
notification calls were discovered.  This is addressed in the patch
"hugetlb: remove duplicate mmu notifications:".  Since there are no user
visible effects, this third is not tagged for stable backports.

Previous discussions suggested further cleanup by removing the
routine zap_page_range.  This is possible because zap_page_range_single
is now exported, and all callers of zap_page_range pass ranges entirely
within a single vma.  This work will be done in a later patch so as not
to distract from this bug fix.

[1] https://lore.kernel.org/lkml/CAO4mrfdLMXsao9RF4fUE8-Wfde8xmjsKrTNMNC9wjUb6JudD0g@mail.gmail.com/

This patch (of 2):

Expose the routine zap_page_range_single to zap a range within a single
vma.  The madvise routine madvise_dontneed_single_vma can use this routine
as it explicitly operates on a single vma.  Also, update the mmu
notification range in zap_page_range_single to take hugetlb pmd sharing
into account.  This is required as MADV_DONTNEED supports hugetlb vmas.

Link: https://lkml.kernel.org/r/20221114235507.294320-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20221114235507.294320-2-mike.kravetz@oracle.com
Fixes: 90e7e7f5ef ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Wei Chen <harperchen1110@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:40:44 +01:00
SeongJae Park f98d1f2a36 mm/damon/sysfs: fix wrong empty schemes assumption under online tuning in damon_sysfs_set_schemes()
[ Upstream commit 95bc35f9be ]

Commit da87878010 ("mm/damon/sysfs: support online inputs update") made
'damon_sysfs_set_schemes()' to be called for running DAMON context, which
could have schemes.  In the case, DAMON sysfs interface is supposed to
update, remove, or add schemes to reflect the sysfs files.  However, the
code is assuming the DAMON context wouldn't have schemes at all, and
therefore creates and adds new schemes.  As a result, the code doesn't
work as intended for online schemes tuning and could have more than
expected memory footprint.  The schemes are all in the DAMON context, so
it doesn't leak the memory, though.

Remove the wrong asssumption (the DAMON context wouldn't have schemes) in
'damon_sysfs_set_schemes()' to fix the bug.

Link: https://lkml.kernel.org/r/20221122194831.3472-1-sj@kernel.org
Fixes: da87878010 ("mm/damon/sysfs: support online inputs update")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[5.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:30:21 +01:00
Yajun Deng fd3e613a91 mm/damon: introduce struct damos_access_pattern
[ Upstream commit f5a79d7c0c ]

damon_new_scheme() has too many parameters, so introduce struct
damos_access_pattern to simplify it.

In additon, we can't use a bpf trace kprobe that has more than 5
parameters.

Link: https://lkml.kernel.org/r/20220908191443.129534-1-sj@kernel.org
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 95bc35f9be ("mm/damon/sysfs: fix wrong empty schemes assumption under online tuning in damon_sysfs_set_schemes()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:30:21 +01:00
Gavin Shan 6d01bb8b5f mm: migrate: fix THP's mapcount on isolation
commit 829ae0f81c upstream.

The issue is reported when removing memory through virtio_mem device.  The
transparent huge page, experienced copy-on-write fault, is wrongly
regarded as pinned.  The transparent huge page is escaped from being
isolated in isolate_migratepages_block().  The transparent huge page can't
be migrated and the corresponding memory block can't be put into offline
state.

Fix it by replacing page_mapcount() with total_mapcount().  With this, the
transparent huge page can be isolated and migrated, and the memory block
can be put into offline state.  Besides, The page's refcount is increased
a bit earlier to avoid the page is released when the check is executed.

Link: https://lkml.kernel.org/r/20221124095523.31061-1-gshan@redhat.com
Fixes: 1da2f328fa ("mm,thp,compaction,cma: allow THP migration for CMA allocations")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reported-by: Zhenyu Zhang <zhenyzha@redhat.com>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>	[5.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08 11:30:19 +01:00
Li Liguang f3e17b13ac mm: correctly charge compressed memory to its memcg
commit cd08d80ecd upstream.

Kswapd will reclaim memory when memory pressure is high, the annonymous
memory will be compressed and stored in the zpool if zswap is enabled.
The memcg_kmem_bypass() in get_obj_cgroup_from_page() will bypass the
kernel thread and cause the compressed memory not be charged to its memory
cgroup.

Remove the memcg_kmem_bypass() call and properly charge compressed memory
to its corresponding memory cgroup.

Link: https://lore.kernel.org/linux-mm/CALvZod4nnn8BHYqAM4xtcR0Ddo2-Wr8uKm9h_CHWUaXw7g_DCg@mail.gmail.com/
Link: https://lkml.kernel.org/r/20221114194828.100822-1-hannes@cmpxchg.org
Fixes: f4840ccfca ("zswap: memcg accounting")
Signed-off-by: Li Liguang <liliguang@baidu.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: <stable@vger.kernel.org>	[5.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-02 17:43:13 +01:00
Qi Zheng 51a83f65e5 mm: fix unexpected changes to {failslab|fail_page_alloc}.attr
commit ea4452de2a upstream.

When we specify __GFP_NOWARN, we only expect that no warnings will be
issued for current caller.  But in the __should_failslab() and
__should_fail_alloc_page(), the local GFP flags alter the global
{failslab|fail_page_alloc}.attr, which is persistent and shared by all
tasks.  This is not what we expected, let's fix it.

[akpm@linux-foundation.org: unexport should_fail_ex()]
Link: https://lkml.kernel.org/r/20221118100011.2634-1-zhengqi.arch@bytedance.com
Fixes: 3f913fc5f9 ("mm: fix missing handler for __GFP_NOWARN")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-02 17:43:13 +01:00
Johannes Weiner cb546d436b mm: vmscan: fix extreme overreclaim and swap floods
commit f53af4285d upstream.

During proactive reclaim, we sometimes observe severe overreclaim, with
several thousand times more pages reclaimed than requested.

This trace was obtained from shrink_lruvec() during such an instance:

    prio:0 anon_cost:1141521 file_cost:7767
    nr_reclaimed:4387406 nr_to_reclaim:1047 (or_factor:4190)
    nr=[7161123 345 578 1111]

While he reclaimer requested 4M, vmscan reclaimed close to 16G, most of it
by swapping.  These requests take over a minute, during which the write()
to memory.reclaim is unkillably stuck inside the kernel.

Digging into the source, this is caused by the proportional reclaim
bailout logic.  This code tries to resolve a fundamental conflict: to
reclaim roughly what was requested, while also aging all LRUs fairly and
in accordance to their size, swappiness, refault rates etc.  The way it
attempts fairness is that once the reclaim goal has been reached, it stops
scanning the LRUs with the smaller remaining scan targets, and adjusts the
remainder of the bigger LRUs according to how much of the smaller LRUs was
scanned.  It then finishes scanning that remainder regardless of the
reclaim goal.

This works fine if priority levels are low and the LRU lists are
comparable in size.  However, in this instance, the cgroup that is
targeted by proactive reclaim has almost no files left - they've already
been squeezed out by proactive reclaim earlier - and the remaining anon
pages are hot.  Anon rotations cause the priority level to drop to 0,
which results in reclaim targeting all of anon (a lot) and all of file
(almost nothing).  By the time reclaim decides to bail, it has scanned
most or all of the file target, and therefor must also scan most or all of
the enormous anon target.  This target is thousands of times larger than
the reclaim goal, thus causing the overreclaim.

The bailout code hasn't changed in years, why is this failing now?  The
most likely explanations are two other recent changes in anon reclaim:

1. Before the series starting with commit 5df741963d ("mm: fix LRU
   balancing effect of new transparent huge pages"), the VM was
   overall relatively reluctant to swap at all, even if swap was
   configured. This means the LRU balancing code didn't come into play
   as often as it does now, and mostly in high pressure situations
   where pronounced swap activity wouldn't be as surprising.

2. For historic reasons, shrink_lruvec() loops on the scan targets of
   all LRU lists except the active anon one, meaning it would bail if
   the only remaining pages to scan were active anon - even if there
   were a lot of them.

   Before the series starting with commit ccc5dc6734 ("mm/vmscan:
   make active/inactive ratio as 1:1 for anon lru"), most anon pages
   would live on the active LRU; the inactive one would contain only a
   handful of preselected reclaim candidates. After the series, anon
   gets aged similarly to file, and the inactive list is the default
   for new anon pages as well, making it often the much bigger list.

   As a result, the VM is now more likely to actually finish large
   anon targets than before.

Change the code such that only one SWAP_CLUSTER_MAX-sized nudge toward the
larger LRU lists is made before bailing out on a met reclaim goal.

This fixes the extreme overreclaim problem.

Fairness is more subtle and harder to evaluate.  No obvious misbehavior
was observed on the test workload, in any case.  Conceptually, fairness
should primarily be a cumulative effect from regular, lower priority
scans.  Once the VM is in trouble and needs to escalate scan targets to
make forward progress, fairness needs to take a backseat.  This is also
acknowledged by the myriad exceptions in get_scan_count().  This patch
makes fairness decrease gradually, as it keeps fairness work static over
increasing priority levels with growing scan targets.  This should make
more sense - although we may have to re-visit the exact values.

Link: https://lkml.kernel.org/r/20220802162811.39216-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-02 17:43:12 +01:00
Aneesh Kumar K.V b1f82e84c6 mm/cgroup/reclaim: fix dirty pages throttling on cgroup v1
commit 81a70c21d9 upstream.

balance_dirty_pages doesn't do the required dirty throttling on cgroupv1.
See commit 9badce000e ("cgroup, writeback: don't enable cgroup writeback
on traditional hierarchies").  Instead, the kernel depends on writeback
throttling in shrink_folio_list to achieve the same goal.  With large
memory systems, the flusher may not be able to writeback quickly enough
such that we will start finding pages in the shrink_folio_list already in
writeback.  Hence for cgroupv1 let's do a reclaim throttle after waking up
the flusher.

The below test which used to fail on a 256GB system completes till the the
file system is full with this change.

root@lp2:/sys/fs/cgroup/memory# mkdir test
root@lp2:/sys/fs/cgroup/memory# cd test/
root@lp2:/sys/fs/cgroup/memory/test# echo 120M > memory.limit_in_bytes
root@lp2:/sys/fs/cgroup/memory/test# echo $$ > tasks
root@lp2:/sys/fs/cgroup/memory/test# dd if=/dev/zero of=/home/kvaneesh/test bs=1M
Killed

Link: https://lkml.kernel.org/r/20221118070603.84081-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: zefan li <lizefan.x@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-02 17:43:12 +01:00
SeongJae Park dfb8a23d93 mm/damon/sysfs-schemes: skip stats update if the scheme directory is removed
commit 8468b48661 upstream.

A DAMON sysfs interface user can start DAMON with a scheme, remove the
sysfs directory for the scheme, and then ask update of the scheme's stats.
Because the schemes stats update logic isn't aware of the situation, it
results in an invalid memory access.  Fix the bug by checking if the
scheme sysfs directory exists.

Link: https://lkml.kernel.org/r/20221114175552.1951-1-sj@kernel.org
Fixes: 0ac32b8aff ("mm/damon/sysfs: support DAMOS stats")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[v5.18]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-02 17:43:10 +01:00
Alexander Potapenko 80ec940ee5 mm: fs: initialize fsdata passed to write_begin/write_end interface
commit 1468c6f455 upstream.

Functions implementing the a_ops->write_end() interface accept the `void
*fsdata` parameter that is supposed to be initialized by the corresponding
a_ops->write_begin() (which accepts `void **fsdata`).

However not all a_ops->write_begin() implementations initialize `fsdata`
unconditionally, so it may get passed uninitialized to a_ops->write_end(),
resulting in undefined behavior.

Fix this by initializing fsdata with NULL before the call to
write_begin(), rather than doing so in all possible a_ops implementations.

This patch covers only the following cases found by running x86 KMSAN
under syzkaller:

 - generic_perform_write()
 - cont_expand_zero() and generic_cont_expand_simple()
 - page_symlink()

Other cases of passing uninitialized fsdata may persist in the codebase.

Link: https://lkml.kernel.org/r/20220915150417.722975-43-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-26 09:27:56 +01:00
Alban Crequy 47e9fa266a maccess: Fix writing offset in case of fault in strncpy_from_kernel_nofault()
commit 8678ea0685 upstream.

If a page fault occurs while copying the first byte, this function resets one
byte before dst.
As a consequence, an address could be modified and leaded to kernel crashes if
case the modified address was accessed later.

Fixes: b58294ead1 ("maccess: allow architectures to provide kernel probing directly")
Signed-off-by: Alban Crequy <albancrequy@linux.microsoft.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Francis Laniel <flaniel@linux.microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org> [5.8]
Link: https://lore.kernel.org/bpf/20221110085614.111213-2-albancrequy@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-26 09:27:49 +01:00
James Houghton ec667443b2 hugetlbfs: don't delete error page from pagecache
[ Upstream commit 8625147caf ]

This change is very similar to the change that was made for shmem [1], and
it solves the same problem but for HugeTLBFS instead.

Currently, when poison is found in a HugeTLB page, the page is removed
from the page cache.  That means that attempting to map or read that
hugepage in the future will result in a new hugepage being allocated
instead of notifying the user that the page was poisoned.  As [1] states,
this is effectively memory corruption.

The fix is to leave the page in the page cache.  If the user attempts to
use a poisoned HugeTLB page with a syscall, the syscall will fail with
EIO, the same error code that shmem uses.  For attempts to map the page,
the thread will get a BUS_MCEERR_AR SIGBUS.

[1]: commit a760542666 ("mm: shmem: don't truncate page if memory failure happens")

Link: https://lkml.kernel.org/r/20221018200125.848471-1-jthoughton@google.com
Signed-off-by: James Houghton <jthoughton@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Tested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-26 09:27:22 +01:00
Mike Kravetz cf5bf29e9e hugetlb: rename remove_huge_page to hugetlb_delete_from_page_cache
[ Upstream commit 7e1813d48d ]

remove_huge_page removes a hugetlb page from the page cache.  Change to
hugetlb_delete_from_page_cache as it is a more descriptive name.
huge_add_to_page_cache is global in scope, but only deals with hugetlb
pages.  For consistency and clarity, rename to hugetlb_add_to_page_cache.

Link: https://lkml.kernel.org/r/20220914221810.95771-4-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 8625147caf ("hugetlbfs: don't delete error page from pagecache")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-26 09:27:22 +01:00
Peter Xu c50396a822 mm/shmem: use page_mapping() to detect page cache for uffd continue
commit 93b0d91787 upstream.

mfill_atomic_install_pte() checks page->mapping to detect whether one page
is used in the page cache.  However as pointed out by Matthew, the page
can logically be a tail page rather than always the head in the case of
uffd minor mode with UFFDIO_CONTINUE.  It means we could wrongly install
one pte with shmem thp tail page assuming it's an anonymous page.

It's not that clear even for anonymous page, since normally anonymous
pages also have page->mapping being setup with the anon vma.  It's safe
here only because the only such caller to mfill_atomic_install_pte() is
always passing in a newly allocated page (mcopy_atomic_pte()), whose
page->mapping is not yet setup.  However that's not extremely obvious
either.

For either of above, use page_mapping() instead.

Link: https://lkml.kernel.org/r/Y2K+y7wnhC4vbnP2@x1n
Fixes: 153132571f ("userfaultfd/shmem: support UFFDIO_CONTINUE for shmem")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-16 10:04:10 +01:00
Pankaj Gupta 83f89c90b1 mm/memremap.c: map FS_DAX device memory as decrypted
commit 867400af90 upstream.

virtio_pmem use devm_memremap_pages() to map the device memory.  By
default this memory is mapped as encrypted with SEV.  Guest reboot changes
the current encryption key and guest no longer properly decrypts the FSDAX
device meta data.

Mark the corresponding device memory region for FSDAX devices (mapped with
memremap_pages) as decrypted to retain the persistent memory property.

Link: https://lkml.kernel.org/r/20221102160728.3184016-1-pankaj.gupta@amd.com
Fixes: b7b3c01b19 ("mm/memremap_pages: support multiple ranges per invocation")
Signed-off-by: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-16 10:04:10 +01:00
SeongJae Park 599e798e3b mm/damon/dbgfs: check if rm_contexts input is for a real context
commit 1de09a7281 upstream.

A user could write a name of a file under 'damon/' debugfs directory,
which is not a user-created context, to 'rm_contexts' file.  In the case,
'dbgfs_rm_context()' just assumes it's the valid DAMON context directory
only if a file of the name exist.  As a result, invalid memory access
could happen as below.  Fix the bug by checking if the given input is for
a directory.  This check can filter out non-context inputs because
directories under 'damon/' debugfs directory can be created via only
'mk_contexts' file.

This bug has found by syzbot[1].

[1] https://lore.kernel.org/damon/000000000000ede3ac05ec4abf8e@google.com/

Link: https://lkml.kernel.org/r/20221107165001.5717-2-sj@kernel.org
Fixes: 75c1c2b53c ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: syzbot+6087eafb76a94c4ac9eb@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>	[5.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-16 10:04:10 +01:00
Vasily Gorbik d51c525d63 mm: hugetlb_vmemmap: include missing linux/moduleparam.h
commit db5e8d8431 upstream.

The kernel test robot reported build failures with a 'randconfig' on s390:
>> mm/hugetlb_vmemmap.c:421:11: error: a function declaration without a
prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
   core_param(hugetlb_free_vmemmap, vmemmap_optimize_enabled, bool, 0);
             ^

Link: https://lore.kernel.org/linux-mm/202210300751.rG3UDsuc-lkp@intel.com/
Link: https://lkml.kernel.org/r/patch.git-296b83ca939b.your-ad-here.call-01667411912-ext-5073@work.hours
Fixes: 30152245c6 ("mm: hugetlb_vmemmap: replace early_param() with core_param()")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-16 10:04:10 +01:00
Hugh Dickins 6c093b5718 mm: prep_compound_tail() clear page->private
commit 5aae9265ee upstream.

Although page allocation always clears page->private in the first page or
head page of an allocation, it has never made a point of clearing
page->private in the tails (though 0 is often what is already there).

But now commit 71e2d666ef ("mm/huge_memory: do not clobber swp_entry_t
during THP split") issues a warning when page_tail->private is found to be
non-0 (unless it's swapcache).

Change that warning to dump page_tail (which also dumps head), instead of
just the head: so far we have seen dead000000000122, dead000000000003,
dead000000000001 or 0000000000000002 in the raw output for tail private.

We could just delete the warning, but today's consensus appears to want
page->private to be 0, unless there's a good reason for it to be set: so
now clear it in prep_compound_tail() (more general than just for THP; but
not for high order allocation, which makes no pass down the tails).

Link: https://lkml.kernel.org/r/1c4233bb-4e4d-5969-fbd4-96604268a285@google.com
Fixes: 71e2d666ef ("mm/huge_memory: do not clobber swp_entry_t during THP split")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-04 00:00:23 +09:00
Mel Gorman 8cace0eeb0 mm/huge_memory: do not clobber swp_entry_t during THP split
commit 71e2d666ef upstream.

The following has been observed when running stressng mmap since commit
b653db7735 ("mm: Clear page->private when splitting or migrating a page")

   watchdog: BUG: soft lockup - CPU#75 stuck for 26s! [stress-ng:9546]
   CPU: 75 PID: 9546 Comm: stress-ng Tainted: G            E      6.0.0-revert-b653db77-fix+ #29 0357d79b60fb09775f678e4f3f64ef0579ad1374
   Hardware name: SGI.COM C2112-4GP3/X10DRT-P-Series, BIOS 2.0a 05/09/2016
   RIP: 0010:xas_descend+0x28/0x80
   Code: cc cc 0f b6 0e 48 8b 57 08 48 d3 ea 83 e2 3f 89 d0 48 83 c0 04 48 8b 44 c6 08 48 89 77 18 48 89 c1 83 e1 03 48 83 f9 02 75 08 <48> 3d fd 00 00 00 76 08 88 57 12 c3 cc cc cc cc 48 c1 e8 02 89 c2
   RSP: 0018:ffffbbf02a2236a8 EFLAGS: 00000246
   RAX: ffff9cab7d6a0002 RBX: ffffe04b0af88040 RCX: 0000000000000002
   RDX: 0000000000000030 RSI: ffff9cab60509b60 RDI: ffffbbf02a2236c0
   RBP: 0000000000000000 R08: ffff9cab60509b60 R09: ffffbbf02a2236c0
   R10: 0000000000000001 R11: ffffbbf02a223698 R12: 0000000000000000
   R13: ffff9cab4e28da80 R14: 0000000000039c01 R15: ffff9cab4e28da88
   FS:  00007fab89b85e40(0000) GS:ffff9cea3fcc0000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00007fab84e00000 CR3: 00000040b73a4003 CR4: 00000000003706e0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   Call Trace:
    <TASK>
    xas_load+0x3a/0x50
    __filemap_get_folio+0x80/0x370
    ? put_swap_page+0x163/0x360
    pagecache_get_page+0x13/0x90
    __try_to_reclaim_swap+0x50/0x190
    scan_swap_map_slots+0x31e/0x670
    get_swap_pages+0x226/0x3c0
    folio_alloc_swap+0x1cc/0x240
    add_to_swap+0x14/0x70
    shrink_page_list+0x968/0xbc0
    reclaim_page_list+0x70/0xf0
    reclaim_pages+0xdd/0x120
    madvise_cold_or_pageout_pte_range+0x814/0xf30
    walk_pgd_range+0x637/0xa30
    __walk_page_range+0x142/0x170
    walk_page_range+0x146/0x170
    madvise_pageout+0xb7/0x280
    ? asm_common_interrupt+0x22/0x40
    madvise_vma_behavior+0x3b7/0xac0
    ? find_vma+0x4a/0x70
    ? find_vma+0x64/0x70
    ? madvise_vma_anon_name+0x40/0x40
    madvise_walk_vmas+0xa6/0x130
    do_madvise+0x2f4/0x360
    __x64_sys_madvise+0x26/0x30
    do_syscall_64+0x5b/0x80
    ? do_syscall_64+0x67/0x80
    ? syscall_exit_to_user_mode+0x17/0x40
    ? do_syscall_64+0x67/0x80
    ? syscall_exit_to_user_mode+0x17/0x40
    ? do_syscall_64+0x67/0x80
    ? do_syscall_64+0x67/0x80
    ? common_interrupt+0x8b/0xa0
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

The problem can be reproduced with the mmtests config
config-workload-stressng-mmap.  It does not always happen and when it
triggers is variable but it has happened on multiple machines.

The intent of commit b653db7735 patch was to avoid the case where
PG_private is clear but folio->private is not-NULL.  However, THP tail
pages uses page->private for "swp_entry_t if folio_test_swapcache()" as
stated in the documentation for struct folio.  This patch only clobbers
page->private for tail pages if the head page was not in swapcache and
warns once if page->private had an unexpected value.

Link: https://lkml.kernel.org/r/20221019134156.zjyyn5aownakvztf@techsingularity.net
Fixes: b653db7735 ("mm: Clear page->private when splitting or migrating a page")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-04 00:00:23 +09:00
Waiman Long 37fd7341de mm/kmemleak: prevent soft lockup in kmemleak_scan()'s object iteration loops
commit 984a608377 upstream.

Commit 6edda04ccc ("mm/kmemleak: prevent soft lockup in first object
iteration loop of kmemleak_scan()") adds cond_resched() in the first
object iteration loop of kmemleak_scan().  However, it turns that the 2nd
objection iteration loop can still cause soft lockup to happen in some
cases.  So add a cond_resched() call in the 2nd and 3rd loops as well to
prevent that and for completeness.

Link: https://lkml.kernel.org/r/20221020175619.366317-1-longman@redhat.com
Fixes: 6edda04ccc ("mm/kmemleak: prevent soft lockup in first object iteration loop of kmemleak_scan()")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-04 00:00:23 +09:00
Rik van Riel 2ca5a1d93d mm,madvise,hugetlb: fix unexpected data loss with MADV_DONTNEED on hugetlbfs
commit 8ebe0a5eaa upstream.

A common use case for hugetlbfs is for the application to create
memory pools backed by huge pages, which then get handed over to
some malloc library (eg. jemalloc) for further management.

That malloc library may be doing MADV_DONTNEED calls on memory
that is no longer needed, expecting those calls to happen on
PAGE_SIZE boundaries.

However, currently the MADV_DONTNEED code rounds up any such
requests to HPAGE_PMD_SIZE boundaries. This leads to undesired
outcomes when jemalloc expects a 4kB MADV_DONTNEED, but 2MB of
memory get zeroed out, instead.

Use of pre-built shared libraries means that user code does not
always know the page size of every memory arena in use.

Avoid unexpected data loss with MADV_DONTNEED by rounding up
only to PAGE_SIZE (in do_madvise), and rounding down to huge
page granularity.

That way programs will only get as much memory zeroed out as
they requested.

Link: https://lkml.kernel.org/r/20221021192805.366ad573@imladris.surriel.com
Fixes: 90e7e7f5ef ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-04 00:00:23 +09:00
Baolin Wang 7f8a854559 mm: migrate: fix return value if all subpages of THPs are migrated successfully
commit 03e5f82ea6 upstream.

During THP migration, if THPs are not migrated but they are split and all
subpages are migrated successfully, migrate_pages() will still return the
number of THP pages that were not migrated.  This will confuse the callers
of migrate_pages().  For example, the longterm pinning will failed though
all pages are migrated successfully.

Thus we should return 0 to indicate that all pages are migrated in this
case

Link: https://lkml.kernel.org/r/de386aa864be9158d2f3b344091419ea7c38b2f7.1666599848.git.baolin.wang@linux.alibaba.com
Fixes: b5bade978e ("mm: migrate: fix the return value of migrate_pages()")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-04 00:00:23 +09:00
Rik van Riel c828fab903 mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages
commit 12df140f0b upstream.

The h->*_huge_pages counters are protected by the hugetlb_lock, but
alloc_huge_page has a corner case where it can decrement the counter
outside of the lock.

This could lead to a corrupted value of h->resv_huge_pages, which we have
observed on our systems.

Take the hugetlb_lock before decrementing h->resv_huge_pages to avoid a
potential race.

Link: https://lkml.kernel.org/r/20221017202505.0e6a4fcd@imladris.surriel.com
Fixes: a88c769548 ("mm: hugetlb: fix hugepage memory leak caused by wrong reserve count")
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Glen McCready <gkmccready@meta.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-29 10:08:30 +02:00
Liu Shixin 78504bcedb mm: hugetlb: fix UAF in hugetlb_handle_userfault
commit 958f32ce83 upstream.

The vma_lock and hugetlb_fault_mutex are dropped before handling userfault
and reacquire them again after handle_userfault(), but reacquire the
vma_lock could lead to UAF[1,2] due to the following race,

hugetlb_fault
  hugetlb_no_page
    /*unlock vma_lock */
    hugetlb_handle_userfault
      handle_userfault
        /* unlock mm->mmap_lock*/
                                           vm_mmap_pgoff
                                             do_mmap
                                               mmap_region
                                                 munmap_vma_range
                                                   /* clean old vma */
        /* lock vma_lock again  <--- UAF */
    /* unlock vma_lock */

Since the vma_lock will unlock immediately after
hugetlb_handle_userfault(), let's drop the unneeded lock and unlock in
hugetlb_handle_userfault() to fix the issue.

[1] https://lore.kernel.org/linux-mm/000000000000d5e00a05e834962e@google.com/
[2] https://lore.kernel.org/linux-mm/20220921014457.1668-1-liuzixian4@huawei.com/
Link: https://lkml.kernel.org/r/20220923042113.137273-1-liushixin2@huawei.com
Fixes: 1a1aad8a9b ("userfaultfd: hugetlbfs: add userfaultfd hugetlb hook")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reported-by: syzbot+193f9cee8638750b23cf@syzkaller.appspotmail.com
Reported-by: Liu Zixian <liuzixian4@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: <stable@vger.kernel.org>	[4.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-21 12:39:27 +02:00
Carlos Llamas 66f2ed0172 mm/mmap: undo ->mmap() when arch_validate_flags() fails
commit deb0f65628 upstream.

Commit c462ac288f ("mm: Introduce arch_validate_flags()") added a late
check in mmap_region() to let architectures validate vm_flags.  The check
needs to happen after calling ->mmap() as the flags can potentially be
modified during this callback.

If arch_validate_flags() check fails we unmap and free the vma.  However,
the error path fails to undo the ->mmap() call that previously succeeded
and depending on the specific ->mmap() implementation this translates to
reference increments, memory allocations and other operations what will
not be cleaned up.

There are several places (mainly device drivers) where this is an issue.
However, one specific example is bpf_map_mmap() which keeps count of the
mappings in map->writecnt.  The count is incremented on ->mmap() and then
decremented on vm_ops->close().  When arch_validate_flags() fails this
count is off since bpf_map_mmap_close() is never called.

One can reproduce this issue in arm64 devices with MTE support.  Here the
vm_flags are checked to only allow VM_MTE if VM_MTE_ALLOWED has been set
previously.  From userspace then is enough to pass the PROT_MTE flag to
mmap() syscall to trigger the arch_validate_flags() failure.

The following program reproduces this issue:

  #include <stdio.h>
  #include <unistd.h>
  #include <linux/unistd.h>
  #include <linux/bpf.h>
  #include <sys/mman.h>

  int main(void)
  {
	union bpf_attr attr = {
		.map_type = BPF_MAP_TYPE_ARRAY,
		.key_size = sizeof(int),
		.value_size = sizeof(long long),
		.max_entries = 256,
		.map_flags = BPF_F_MMAPABLE,
	};
	int fd;

	fd = syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
	mmap(NULL, 4096, PROT_WRITE | PROT_MTE, MAP_SHARED, fd, 0);

	return 0;
  }

By manually adding some log statements to the vm_ops callbacks we can
confirm that when passing PROT_MTE to mmap() the map->writecnt is off upon
->release():

With PROT_MTE flag:
  root@debian:~# ./bpf-test
  [  111.263874] bpf_map_write_active_inc: map=9 writecnt=1
  [  111.288763] bpf_map_release: map=9 writecnt=1

Without PROT_MTE flag:
  root@debian:~# ./bpf-test
  [  157.816912] bpf_map_write_active_inc: map=10 writecnt=1
  [  157.830442] bpf_map_write_active_dec: map=10 writecnt=0
  [  157.832396] bpf_map_release: map=10 writecnt=0

This patch fixes the above issue by calling vm_ops->close() when the
arch_validate_flags() check fails, after this we can proceed to unmap and
free the vma on the error path.

Link: https://lkml.kernel.org/r/20220930003844.1210987-1-cmllamas@google.com
Fixes: c462ac288f ("mm: Introduce arch_validate_flags()")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Liam Howlett <liam.howlett@oracle.com>
Cc: Christian Brauner (Microsoft) <brauner@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>	[5.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-21 12:37:42 +02:00
Peter Xu 2204a880cb mm/uffd: fix warning without PTE_MARKER_UFFD_WP compiled in
commit 515778e2d7 upstream.

When PTE_MARKER_UFFD_WP not configured, it's still possible to reach pte
marker code and trigger an warning. Add a few CONFIG_PTE_MARKER_UFFD_WP
ifdefs to make sure the code won't be reached when not compiled in.

Link: https://lkml.kernel.org/r/YzeR+R6b4bwBlBHh@x1n
Fixes: b1f9e87686 ("mm/uffd: enable write protection for shmem & hugetlbfs")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: <syzbot+2b9b4f0895be09a6dec3@syzkaller.appspotmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Edward Liaw <edliaw@google.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-21 12:37:42 +02:00
Baolin Wang 2b04ccc111 mm/damon: validate if the pmd entry is present before accessing
commit c8b9aff419 upstream.

pmd_huge() is used to validate if the pmd entry is mapped by a huge page,
also including the case of non-present (migration or hwpoisoned) pmd entry
on arm64 or x86 architectures.  This means that pmd_pfn() can not get the
correct pfn number for a non-present pmd entry, which will cause
damon_get_page() to get an incorrect page struct (also may be NULL by
pfn_to_online_page()), making the access statistics incorrect.

This means that the DAMON may make incorrect decision according to the
incorrect statistics, for example, DAMON may can not reclaim cold page
in time due to this cold page was regarded as accessed mistakenly if
DAMOS_PAGEOUT operation is specified.

Moreover it does not make sense that we still waste time to get the page
of the non-present entry.  Just treat it as not-accessed and skip it,
which maintains consistency with non-present pte level entries.

So add pmd entry present validation to fix the above issues.

Link: https://lkml.kernel.org/r/58b1d1f5fbda7db49ca886d9ef6783e3dcbbbc98.1660805030.git.baolin.wang@linux.alibaba.com
Fixes: 3f49584b26 ("mm/damon: implement primitives for the virtual memory address spaces")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-21 12:37:42 +02:00
Baolin Wang 7c7c79dd5a mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page
commit fac35ba763 upstream.

On some architectures (like ARM64), it can support CONT-PTE/PMD size
hugetlb, which means it can support not only PMD/PUD size hugetlb (2M and
1G), but also CONT-PTE/PMD size(64K and 32M) if a 4K page size specified.

So when looking up a CONT-PTE size hugetlb page by follow_page(), it will
use pte_offset_map_lock() to get the pte entry lock for the CONT-PTE size
hugetlb in follow_page_pte().  However this pte entry lock is incorrect
for the CONT-PTE size hugetlb, since we should use huge_pte_lock() to get
the correct lock, which is mm->page_table_lock.

That means the pte entry of the CONT-PTE size hugetlb under current pte
lock is unstable in follow_page_pte(), we can continue to migrate or
poison the pte entry of the CONT-PTE size hugetlb, which can cause some
potential race issues, even though they are under the 'pte lock'.

For example, suppose thread A is trying to look up a CONT-PTE size hugetlb
page by move_pages() syscall under the lock, however antoher thread B can
migrate the CONT-PTE hugetlb page at the same time, which will cause
thread A to get an incorrect page, if thread A also wants to do page
migration, then data inconsistency error occurs.

Moreover we have the same issue for CONT-PMD size hugetlb in
follow_huge_pmd().

To fix above issues, rename the follow_huge_pmd() as follow_huge_pmd_pte()
to handle PMD and PTE level size hugetlb, which uses huge_pte_lock() to
get the correct pte entry lock to make the pte entry stable.

Mike said:

Support for CONT_PMD/_PTE was added with bb9dd3df8e ("arm64: hugetlb:
refactor find_num_contig()").  Patch series "Support for contiguous pte
hugepages", v4.  However, I do not believe these code paths were
executed until migration support was added with 5480280d3f ("arm64/mm:
enable HugeTLB migration for contiguous bit HugeTLB pages") I would go
with 5480280d3f for the Fixes: targe.

Link: https://lkml.kernel.org/r/635f43bdd85ac2615a58405da82b4d33c6e5eb05.1662017562.git.baolin.wang@linux.alibaba.com
Fixes: 5480280d3f ("arm64/mm: enable HugeTLB migration for contiguous bit HugeTLB pages")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-21 12:37:42 +02:00
Linus Torvalds 2a4b6e13e1 One MAINTAINERS update, two MM fixes, both cc:stable
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Merge tag 'mm-hotfixes-stable-2022-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more hotfixes from Andrew Morton:
 "One MAINTAINERS update, two MM fixes, both cc:stable"

The previous pull wasn't fated to be the last one..

* tag 'mm-hotfixes-stable-2022-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  damon/sysfs: fix possible memleak on damon_sysfs_add_target
  mm: fix BUG splat with kvmalloc + GFP_ATOMIC
  MAINTAINERS: drop entry to removed file in ARM/RISCPC ARCHITECTURE
2022-10-01 09:13:29 -07:00
Levi Yun 1c8e2349f2 damon/sysfs: fix possible memleak on damon_sysfs_add_target
When damon_sysfs_add_target couldn't find proper task, New allocated
damon_target structure isn't registered yet, So, it's impossible to free
new allocated one by damon_sysfs_destroy_targets.

By calling damon_add_target as soon as allocating new target, Fix this
possible memory leak.

Link: https://lkml.kernel.org/r/20220926160611.48536-1-sj@kernel.org
Fixes: a61ea561c8 ("mm/damon/sysfs: link DAMON for virtual address spaces monitoring")
Signed-off-by: Levi Yun <ppbuk5246@gmail.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[5.17.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-30 18:46:31 -07:00
Florian Westphal 30c1936663 mm: fix BUG splat with kvmalloc + GFP_ATOMIC
Martin Zaharinov reports BUG with 5.19.10 kernel:
 kernel BUG at mm/vmalloc.c:2437!
 invalid opcode: 0000 [#1] SMP
 CPU: 28 PID: 0 Comm: swapper/28 Tainted: G        W  O      5.19.9 #1
 [..]
 RIP: 0010:__get_vm_area_node+0x120/0x130
  __vmalloc_node_range+0x96/0x1e0
  kvmalloc_node+0x92/0xb0
  bucket_table_alloc.isra.0+0x47/0x140
  rhashtable_try_insert+0x3a4/0x440
  rhashtable_insert_slow+0x1b/0x30
 [..]

bucket_table_alloc uses kvzalloc(GPF_ATOMIC).  If kmalloc fails, this now
falls through to vmalloc and hits code paths that assume GFP_KERNEL.

Link: https://lkml.kernel.org/r/20220926151650.15293-1-fw@strlen.de
Fixes: a421ef3030 ("mm: allow !GFP_KERNEL allocations for kvmalloc")
Signed-off-by: Florian Westphal <fw@strlen.de>
Suggested-by: Michal Hocko <mhocko@suse.com>
Link: https://lore.kernel.org/linux-mm/Yy3MS2uhSgjF47dy@pc636/T/#t
Acked-by: Michal Hocko <mhocko@suse.com>
Reported-by: Martin Zaharinov <micron10@gmail.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-30 18:46:31 -07:00
Linus Torvalds 3800a713b6 26 hotfixes. 8 are for issues which were introduced during this -rc
cycle, 18 are for earlier issues, and are cc:stable.
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Merge tag 'mm-hotfixes-stable-2022-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull last (?) hotfixes from Andrew Morton:
 "26 hotfixes.

  8 are for issues which were introduced during this -rc cycle, 18 are
  for earlier issues, and are cc:stable"

* tag 'mm-hotfixes-stable-2022-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (26 commits)
  x86/uaccess: avoid check_object_size() in copy_from_user_nmi()
  mm/page_isolation: fix isolate_single_pageblock() isolation behavior
  mm,hwpoison: check mm when killing accessing process
  mm/hugetlb: correct demote page offset logic
  mm: prevent page_frag_alloc() from corrupting the memory
  mm: bring back update_mmu_cache() to finish_fault()
  frontswap: don't call ->init if no ops are registered
  mm/huge_memory: use pfn_to_online_page() in split_huge_pages_all()
  mm: fix madivse_pageout mishandling on non-LRU page
  powerpc/64s/radix: don't need to broadcast IPI for radix pmd collapse flush
  mm: gup: fix the fast GUP race against THP collapse
  mm: fix dereferencing possible ERR_PTR
  vmscan: check folio_test_private(), not folio_get_private()
  mm: fix VM_BUG_ON in __delete_from_swap_cache()
  tools: fix compilation after gfp_types.h split
  mm/damon/dbgfs: fix memory leak when using debugfs_lookup()
  mm/migrate_device.c: copy pte dirty bit to page
  mm/migrate_device.c: add missing flush_cache_page()
  mm/migrate_device.c: flush TLB while holding PTL
  x86/mm: disable instrumentations of mm/pgprot.c
  ...
2022-09-26 13:23:15 -07:00
Zi Yan 80e2b584f3 mm/page_isolation: fix isolate_single_pageblock() isolation behavior
set_migratetype_isolate() does not allow isolating MIGRATE_CMA pageblocks
unless it is used for CMA allocation.  isolate_single_pageblock() did not
have the same behavior when it is used together with
set_migratetype_isolate() in start_isolate_page_range().  This allows
alloc_contig_range() with migratetype other than MIGRATE_CMA, like
MIGRATE_MOVABLE (used by alloc_contig_pages()), to isolate first and last
pageblock but fail the rest.  The failure leads to changing migratetype of
the first and last pageblock to MIGRATE_MOVABLE from MIGRATE_CMA,
corrupting the CMA region.  This can happen during gigantic page
allocations.

Like Doug said here:
https://lore.kernel.org/linux-mm/a3363a52-883b-dcd1-b77f-f2bb378d6f2d@gmail.com/T/#u,
for gigantic page allocations, the user would notice no difference,
since the allocation on CMA region will fail as well as it did before. 
But it might hurt the performance of device drivers that use CMA, since
CMA region size decreases.

Fix it by passing migratetype into isolate_single_pageblock(), so that
set_migratetype_isolate() used by isolate_single_pageblock() will prevent
the isolation happening.

Link: https://lkml.kernel.org/r/20220914023913.1855924-1-zi.yan@sent.com
Fixes: b2c9e2fbba ("mm: make alloc_contig_range work at pageblock granularity")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: Doug Berger <opendmb@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:34 -07:00
Shuai Xue 77677cdbc2 mm,hwpoison: check mm when killing accessing process
The GHES code calls memory_failure_queue() from IRQ context to queue work
into workqueue and schedule it on the current CPU.  Then the work is
processed in memory_failure_work_func() by kworker and calls
memory_failure().

When a page is already poisoned, commit a3f5d80ea4 ("mm,hwpoison: send
SIGBUS with error virutal address") make memory_failure() call
kill_accessing_process() that:

    - holds mmap locking of current->mm
    - does pagetable walk to find the error virtual address
    - and sends SIGBUS to the current process with error info.

However, the mm of kworker is not valid, resulting in a null-pointer
dereference.  So check mm when killing the accessing process.

[akpm@linux-foundation.org: remove unrelated whitespace alteration]
Link: https://lkml.kernel.org/r/20220914064935.7851-1-xueshuai@linux.alibaba.com
Fixes: a3f5d80ea4 ("mm,hwpoison: send SIGBUS with error virutal address")
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Bixuan Cui <cuibixuan@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:34 -07:00
Doug Berger 317314527d mm/hugetlb: correct demote page offset logic
With gigantic pages it may not be true that struct page structures are
contiguous across the entire gigantic page.  The nth_page macro is used
here in place of direct pointer arithmetic to correct for this.

Mike said:

: This error could cause addressing exceptions.  However, this is only
: possible in configurations where CONFIG_SPARSEMEM &&
: !CONFIG_SPARSEMEM_VMEMMAP.  Such a configuration option is rare and
: unknown to be the default anywhere.

Link: https://lkml.kernel.org/r/20220914190917.3517663-1-opendmb@gmail.com
Fixes: 8531fc6f52 ("hugetlb: add hugetlb demote page support")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:34 -07:00
Maurizio Lombardi dac22531bb mm: prevent page_frag_alloc() from corrupting the memory
A number of drivers call page_frag_alloc() with a fragment's size >
PAGE_SIZE.

In low memory conditions, __page_frag_cache_refill() may fail the order
3 cache allocation and fall back to order 0; In this case, the cache
will be smaller than the fragment, causing memory corruptions.

Prevent this from happening by checking if the newly allocated cache is
large enough for the fragment; if not, the allocation will fail and
page_frag_alloc() will return NULL.

Link: https://lkml.kernel.org/r/20220715125013.247085-1-mlombard@redhat.com
Fixes: b63ae8ca09 ("mm/net: Rename and move page fragment handling from net/ to mm/")
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Cc: Chen Lin <chen45464546@163.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:34 -07:00
Sergei Antonov 70427f6e9e mm: bring back update_mmu_cache() to finish_fault()
Running this test program on ARMv4 a few times (sometimes just once)
reproduces the bug.

int main()
{
        unsigned i;
        char paragon[SIZE];
        void* ptr;

        memset(paragon, 0xAA, SIZE);
        ptr = mmap(NULL, SIZE, PROT_READ | PROT_WRITE,
                   MAP_ANON | MAP_SHARED, -1, 0);
        if (ptr == MAP_FAILED) return 1;
        printf("ptr = %p\n", ptr);
        for (i=0;i<10000;i++){
                memset(ptr, 0xAA, SIZE);
                if (memcmp(ptr, paragon, SIZE)) {
                        printf("Unexpected bytes on iteration %u!!!\n", i);
                        break;
                }
        }
        munmap(ptr, SIZE);
}

In the "ptr" buffer there appear runs of zero bytes which are aligned
by 16 and their lengths are multiple of 16.

Linux v5.11 does not have the bug, "git bisect" finds the first bad commit:
f9ce0be71d ("mm: Cleanup faultaround and finish_fault() codepaths")

Before the commit update_mmu_cache() was called during a call to
filemap_map_pages() as well as finish_fault(). After the commit
finish_fault() lacks it.

Bring back update_mmu_cache() to finish_fault() to fix the bug.
Also call update_mmu_tlb() only when returning VM_FAULT_NOPAGE to more
closely reproduce the code of alloc_set_pte() function that existed before
the commit.

On many platforms update_mmu_cache() is nop:
 x86, see arch/x86/include/asm/pgtable
 ARMv6+, see arch/arm/include/asm/tlbflush.h
So, it seems, few users ran into this bug.

Link: https://lkml.kernel.org/r/20220908204809.2012451-1-saproj@gmail.com
Fixes: f9ce0be71d ("mm: Cleanup faultaround and finish_fault() codepaths")
Signed-off-by: Sergei Antonov <saproj@gmail.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:34 -07:00
Christoph Hellwig 37dcc673d0 frontswap: don't call ->init if no ops are registered
If no frontswap module (i.e.  zswap) was registered, frontswap_ops will be
NULL.  In such situation, swapon crashes with the following stack trace:

  Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000000
  Mem abort info:
    ESR = 0x0000000096000004
    EC = 0x25: DABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
    FSC = 0x04: level 0 translation fault
  Data abort info:
    ISV = 0, ISS = 0x00000004
    CM = 0, WnR = 0
  user pgtable: 4k pages, 48-bit VAs, pgdp=00000020a4fab000
  [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
  Internal error: Oops: 96000004 [#1] SMP
  Modules linked in: zram fsl_dpaa2_eth pcs_lynx phylink ahci_qoriq crct10dif_ce ghash_ce sbsa_gwdt fsl_mc_dpio nvme lm90 nvme_core at803x xhci_plat_hcd rtc_fsl_ftm_alarm xgmac_mdio ahci_platform i2c_imx ip6_tables ip_tables fuse
  Unloaded tainted modules: cppc_cpufreq():1
  CPU: 10 PID: 761 Comm: swapon Not tainted 6.0.0-rc2-00454-g22100432cf14 #1
  Hardware name: SolidRun Ltd. SolidRun CEX7 Platform, BIOS EDK II Jun 21 2022
  pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : frontswap_init+0x38/0x60
  lr : __do_sys_swapon+0x8a8/0x9f4
  sp : ffff80000969bcf0
  x29: ffff80000969bcf0 x28: ffff37bee0d8fc00 x27: ffff80000a7f5000
  x26: fffffcdefb971e80 x25: ffffaba797453b90 x24: 0000000000000064
  x23: ffff37c1f209d1a8 x22: ffff37bee880e000 x21: ffffaba797748560
  x20: ffff37bee0d8fce4 x19: ffffaba797748488 x18: 0000000000000014
  x17: 0000000030ec029a x16: ffffaba795a479b0 x15: 0000000000000000
  x14: 0000000000000000 x13: 0000000000000030 x12: 0000000000000001
  x11: ffff37c63c0aba18 x10: 0000000000000000 x9 : ffffaba7956b8c88
  x8 : ffff80000969bcd0 x7 : 0000000000000000 x6 : 0000000000000000
  x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffffaba79730f000
  x2 : ffff37bee0d8fc00 x1 : 0000000000000000 x0 : 0000000000000000
  Call trace:
  frontswap_init+0x38/0x60
  __do_sys_swapon+0x8a8/0x9f4
  __arm64_sys_swapon+0x28/0x3c
  invoke_syscall+0x78/0x100
  el0_svc_common.constprop.0+0xd4/0xf4
  do_el0_svc+0x38/0x4c
  el0_svc+0x34/0x10c
  el0t_64_sync_handler+0x11c/0x150
  el0t_64_sync+0x190/0x194
  Code: d000e283 910003fd f9006c41 f946d461 (f9400021)
  ---[ end trace 0000000000000000 ]---

Link: https://lkml.kernel.org/r/20220909130829.3262926-1-hch@lst.de
Fixes: 1da0d94a3e ("frontswap: remove support for multiple ops")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:34 -07:00
Naoya Horiguchi 2b7aa91ba0 mm/huge_memory: use pfn_to_online_page() in split_huge_pages_all()
NULL pointer dereference is triggered when calling thp split via debugfs
on the system with offlined memory blocks.  With debug option enabled, the
following kernel messages are printed out:

  page:00000000467f4890 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x121c000
  flags: 0x17fffc00000000(node=0|zone=2|lastcpupid=0x1ffff)
  raw: 0017fffc00000000 0000000000000000 dead000000000122 0000000000000000
  raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
  page dumped because: unmovable page
  page:000000007d7ab72e is uninitialized and poisoned
  page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
  ------------[ cut here ]------------
  kernel BUG at include/linux/mm.h:1248!
  invalid opcode: 0000 [#1] PREEMPT SMP PTI
  CPU: 16 PID: 20964 Comm: bash Tainted: G          I        6.0.0-rc3-foll-numa+ #41
  ...
  RIP: 0010:split_huge_pages_write+0xcf4/0xe30

This shows that page_to_nid() in page_zone() is unexpectedly called for an
offlined memmap.

Use pfn_to_online_page() to get struct page in PFN walker.

Link: https://lkml.kernel.org/r/20220908041150.3430269-1-naoya.horiguchi@linux.dev
Fixes: f1dd2cd13c ("mm, memory_hotplug: do not associate hotadded memory to zones until online")      [visible after d0dc12e86b]
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Co-developed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>	[5.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:33 -07:00
Minchan Kim 58d426a7ba mm: fix madivse_pageout mishandling on non-LRU page
MADV_PAGEOUT tries to isolate non-LRU pages and gets a warning from
isolate_lru_page below.

Fix it by checking PageLRU in advance.

------------[ cut here ]------------
trying to isolate tail page
WARNING: CPU: 0 PID: 6175 at mm/folio-compat.c:158 isolate_lru_page+0x130/0x140
Modules linked in:
CPU: 0 PID: 6175 Comm: syz-executor.0 Not tainted 5.18.12 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:isolate_lru_page+0x130/0x140

Link: https://lore.kernel.org/linux-mm/485f8c33.2471b.182d5726afb.Coremail.hantianshuo@iie.ac.cn/
Link: https://lkml.kernel.org/r/20220908151204.762596-1-minchan@kernel.org
Fixes: 1a4e58cce8 ("mm: introduce MADV_PAGEOUT")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: 韩天ç`• <hantianshuo@iie.ac.cn>
Suggested-by: Yang Shi <shy828301@gmail.com>
Acked-by: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 12:14:33 -07:00