linux-stable/mm
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
..
damon mm/damon/dbgfs: check if rm_contexts input is for a real context 2022-11-16 10:04:10 +01:00
kasan - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
kfence - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
Kconfig cxl for 6.0 2022-08-10 11:07:26 -07:00
Kconfig.debug Two followon fixes for the post-5.19 series "Use pageblock_order for cma 2022-05-27 11:40:49 -07:00
Makefile mm: shrinkers: introduce debugfs interface for memory shrinkers 2022-07-03 18:08:40 -07:00
backing-dev.c writeback: avoid use-after-free after removing device 2022-08-28 14:02:43 -07:00
balloon_compaction.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-28 14:02:45 -07:00
cma.c Revert "mm/cma.c: remove redundant cma_mutex lock" 2022-05-13 15:11:26 -07:00
cma.h mm/cma: provide option to opt out from exposing pages on activation failure 2022-03-22 15:57:09 -07:00
cma_debug.c mm/cma_debug.c: align the name buffer length as struct cma 2022-07-29 18:07:16 -07:00
cma_sysfs.c
compaction.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
debug.c mm: unexport page_init_poison 2022-03-24 19:06:45 -07:00
debug_page_ref.c
debug_vm_pgtable.c docs: rename Documentation/vm to Documentation/mm 2022-06-27 12:52:53 -07:00
dmapool.c mm/dmapool.c: revert "make dma pool to use kmalloc_node" 2022-01-15 16:30:28 +02:00
early_ioremap.c mm/early_ioremap: declare early_memremap_pgprot_adjust() 2022-03-22 15:57:11 -07:00
fadvise.c riscv: compat: syscall: Add compat_sys_call_table implementation 2022-04-26 13:36:25 -07:00
failslab.c mm: fix missing handler for __GFP_NOWARN 2022-05-19 14:08:55 -07:00
filemap.c mm: fs: initialize fsdata passed to write_begin/write_end interface 2022-11-26 09:27:56 +01:00
folio-compat.c mm/folio-compat: Remove migration compatibility functions 2022-08-02 12:34:04 -04:00
frontswap.c frontswap: don't call ->init if no ops are registered 2022-09-26 12:14:34 -07:00
gup.c mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page 2022-10-21 12:37:42 +02:00
gup_test.c mm: rename is_pinnable_page() to is_longterm_pinnable_page() 2022-07-17 17:14:27 -07:00
gup_test.h
highmem.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
hmm.c mm/hmm: fault non-owner device private entries 2022-07-29 11:33:37 -07:00
huge_memory.c mm: prep_compound_tail() clear page->private 2022-11-04 00:00:23 +09:00
hugetlb.c hugetlbfs: don't delete error page from pagecache 2022-11-26 09:27:22 +01:00
hugetlb_cgroup.c hugetlb_cgroup: fix wrong hugetlb cgroup numa stat 2022-07-29 18:07:17 -07:00
hugetlb_vmemmap.c mm: hugetlb_vmemmap: include missing linux/moduleparam.h 2022-11-16 10:04:10 +01:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: improve hugetlb_vmemmap code readability 2022-08-08 18:06:43 -07:00
hwpoison-inject.c mm/memory-failure: disable unpoison once hw error happens 2022-06-16 19:11:32 -07:00
init-mm.c kernel/fork: Initialize mm's PASID 2022-02-14 19:51:47 +01:00
internal.h - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: Add ioremap/iounmap_allowed() 2022-06-27 12:22:31 +01:00
khugepaged.c mm: gup: fix the fast GUP race against THP collapse 2022-09-26 12:14:33 -07:00
kmemleak.c mm/kmemleak: prevent soft lockup in kmemleak_scan()'s object iteration loops 2022-11-04 00:00:23 +09:00
ksm.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
list_lru.c mm: kmem: make mem_cgroup_from_obj() vmalloc()-safe 2022-06-16 19:48:31 -07:00
maccess.c maccess: Fix writing offset in case of fault in strncpy_from_kernel_nofault() 2022-11-26 09:27:49 +01:00
madvise.c mm,madvise,hugetlb: fix unexpected data loss with MADV_DONTNEED on hugetlbfs 2022-11-04 00:00:23 +09:00
mapping_dirty_helpers.c mm: move tlb_flush_pending inline helpers to mm_inline.h 2022-01-15 16:30:27 +02:00
memblock.c memblock updates for v5.20 2022-08-09 09:48:30 -07:00
memcontrol.c mm: memcontrol: fix potential oom_lock recursion deadlock 2022-07-29 18:07:18 -07:00
memfd.c memfd: fix F_SEAL_WRITE after shmem huge page allocated 2022-03-05 11:08:32 -08:00
memory-failure.c hugetlbfs: don't delete error page from pagecache 2022-11-26 09:27:22 +01:00
memory.c mm/uffd: fix warning without PTE_MARKER_UFFD_WP compiled in 2022-10-21 12:37:42 +02:00
memory_hotplug.c mm: use is_zone_movable_page() helper 2022-07-29 18:07:20 -07:00
mempolicy.c mm/mempolicy: remove unneeded out label 2022-07-29 18:07:16 -07:00
mempool.c mm/mempool: use might_alloc() 2022-06-16 19:48:30 -07:00
memremap.c mm/memremap.c: map FS_DAX device memory as decrypted 2022-11-16 10:04:10 +01:00
memtest.c
migrate.c mm: migrate: fix return value if all subpages of THPs are migrated successfully 2022-11-04 00:00:23 +09:00
migrate_device.c mm/migrate_device.c: copy pte dirty bit to page 2022-09-11 16:22:30 -07:00
mincore.c mm: teach core mm about pte markers 2022-05-13 07:20:09 -07:00
mlock.c mm: handling Non-LRU pages returned by vm_normal_pages 2022-07-17 17:14:28 -07:00
mm_init.c
mmap.c mm/mmap: undo ->mmap() when arch_validate_flags() fails 2022-10-21 12:37:42 +02:00
mmap_lock.c
mmu_gather.c mm/mmu_gather: limit free batch count and add schedule point in tlb_batch_pages_flush 2022-04-28 23:16:12 -07:00
mmu_notifier.c mm/mmu_notifier.c: fix race in mmu_interval_notifier_remove() 2022-04-21 20:01:10 -07:00
mmzone.c Folio changes for 5.18 2022-03-22 17:03:12 -07:00
mprotect.c mm/uffd: fix warning without PTE_MARKER_UFFD_WP compiled in 2022-10-21 12:37:42 +02:00
mremap.c Yang Shi has improved the behaviour of khugepaged collapsing of readonly 2022-05-26 12:32:41 -07:00
msync.c
nommu.c mm: nommu: pass a pointer to virt_to_page() 2022-07-17 17:14:37 -07:00
oom_kill.c mm/oom_kill.c: fix vm_oom_kill_table[] ifdeffery 2022-06-01 15:57:16 -07:00
page-writeback.c writeback: avoid use-after-free after removing device 2022-08-28 14:02:43 -07:00
page_alloc.c mm: prep_compound_tail() clear page->private 2022-11-04 00:00:23 +09:00
page_counter.c mm/page_counter: remove an incorrect call to propagate_protected_usage() 2022-01-15 16:30:27 +02:00
page_ext.c mm: use for_each_online_node and node_online instead of open coding 2022-04-29 14:36:58 -07:00
page_idle.c mm: don't be stuck to rmap lock on reclaim path 2022-05-19 14:08:54 -07:00
page_io.c Yang Shi has improved the behaviour of khugepaged collapsing of readonly 2022-05-26 12:32:41 -07:00
page_isolation.c mm/page_isolation: fix isolate_single_pageblock() isolation behavior 2022-09-26 12:14:34 -07:00
page_owner.c Yang Shi has improved the behaviour of khugepaged collapsing of readonly 2022-05-26 12:32:41 -07:00
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c Six hotfixes. One from Miaohe Lin is considered a minor thing so it isn't 2022-05-27 11:29:35 -07:00
page_vma_mapped.c mm/page_vma_mapped.c: use helper function huge_pte_lock 2022-07-17 17:14:47 -07:00
pagewalk.c mm: pagewalk: Fix race between unmap and page walker 2022-09-03 10:13:13 -07:00
percpu-internal.h percpu: improve percpu_alloc_percpu event trace 2022-05-13 07:20:18 -07:00
percpu-km.c
percpu-stats.c mm: use vmalloc_array and vcalloc for array allocations 2022-03-08 09:30:46 -05:00
percpu-vm.c
percpu.c mm: percpu: use kmemleak_ignore_phys() instead of kmemleak_free() 2022-07-17 17:14:47 -07:00
pgalloc-track.h
pgtable-generic.c mm: avoid unnecessary flush on change_huge_pmd() 2022-05-13 07:20:05 -07:00
process_vm_access.c
ptdump.c mm: pagewalk: Fix race between unmap and page walker 2022-09-03 10:13:13 -07:00
readahead.c filemap: Fix serialization adding transparent huge pages to page cache 2022-06-23 12:22:00 -04:00
rmap.c mm/rmap: Fix anon_vma->degree ambiguity leading to double-reuse 2022-08-31 15:45:10 -07:00
rodata_test.c
secretmem.c mm: fix dereferencing possible ERR_PTR 2022-09-11 16:22:31 -07:00
shmem.c shmem: update folio if shmem_replace_page() updates the page 2022-08-28 14:02:43 -07:00
shrinker_debug.c mm: shrinkers: fix double kfree on shrinker name 2022-07-29 18:07:13 -07:00
shuffle.c
shuffle.h
slab.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
slab.h mm/slab_common: move generic bulk alloc/free functions to SLOB 2022-07-20 13:30:12 +02:00
slab_common.c mm/slab_common: fix possible double free of kmem_cache 2022-09-19 16:27:26 +02:00
slob.c mm/slab_common: move generic bulk alloc/free functions to SLOB 2022-07-20 13:30:12 +02:00
slub.c mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context. 2022-09-22 21:48:48 +02:00
sparse-vmemmap.c mm: hugetlb_vmemmap: move vmemmap code related to HugeTLB to hugetlb_vmemmap.c 2022-08-08 18:06:42 -07:00
sparse.c mm: memory_hotplug: enumerate all supported section flags 2022-07-03 18:08:49 -07:00
swap.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
swap.h mm/khugepaged: try to free transhuge swapcache when possible 2022-07-03 18:08:52 -07:00
swap_cgroup.c mm: use vmalloc_array and vcalloc for array allocations 2022-03-08 09:30:46 -05:00
swap_slots.c arm64: enable THP_SWAP for arm64 2022-07-20 10:52:40 +01:00
swap_state.c mm: fix VM_BUG_ON in __delete_from_swap_cache() 2022-09-11 16:22:31 -07:00
swapfile.c mm/swap: convert delete_from_swap_cache() to take a folio 2022-07-03 18:08:48 -07:00
truncate.c mm: Remove __delete_from_page_cache() 2022-06-29 08:51:05 -04:00
usercopy.c usercopy: use unsigned long instead of uintptr_t 2022-07-01 17:03:38 -07:00
userfaultfd.c mm/shmem: use page_mapping() to detect page cache for uffd continue 2022-11-16 10:04:10 +01:00
util.c mm: fix BUG splat with kvmalloc + GFP_ATOMIC 2022-09-30 18:46:31 -07:00
vmacache.c
vmalloc.c mm/vmalloc: extend __find_vmap_area() with one more argument 2022-07-03 18:08:41 -07:00
vmpressure.c
vmscan.c vmscan: check folio_test_private(), not folio_get_private() 2022-09-11 16:22:31 -07:00
vmstat.c mm: add DEVICE_ZONE to FOR_ALL_ZONES 2022-08-20 15:17:45 -07:00
workingset.c mm: shrinkers: provide shrinkers with names 2022-07-03 18:08:40 -07:00
z3fold.c mm: Convert all PageMovable users to movable_operations 2022-08-02 12:34:03 -04:00
zbud.c
zpool.c zpool: remove the list of pools_head 2022-01-15 16:30:31 +02:00
zsmalloc.c mm/zsmalloc: do not attempt to free IS_ERR handle 2022-08-28 14:02:44 -07:00
zswap.c zswap: memcg accounting 2022-05-19 14:08:53 -07:00