commit f5d4e04634 upstream.
Patch series "nilfs2: fix log writer related issues".
This bug fix series covers three nilfs2 log writer-related issues,
including a timer use-after-free issue and potential deadlock issue on
unmount, and a potential freeze issue in event synchronization found
during their analysis. Details are described in each commit log.
This patch (of 3):
A use-after-free issue has been reported regarding the timer sc_timer on
the nilfs_sc_info structure.
The problem is that even though it is used to wake up a sleeping log
writer thread, sc_timer is not shut down until the nilfs_sc_info structure
is about to be freed, and is used regardless of the thread's lifetime.
Fix this issue by limiting the use of sc_timer only while the log writer
thread is alive.
Link: https://lkml.kernel.org/r/20240520132621.4054-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20240520132621.4054-2-konishi.ryusuke@gmail.com
Fixes: fdce895ea5 ("nilfs2: change sc_timer from a pointer to an embedded one in struct nilfs_sc_info")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: "Bai, Shuangpeng" <sjb7183@psu.edu>
Closes: https://groups.google.com/g/syzkaller/c/MK_LYqtt8ko/m/8rgdWeseAwAJ
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c473bcdd80 ]
clang-14 points out that v_size is always smaller than a 64KB
page size if that is configured by the CPU architecture:
fs/nilfs2/ioctl.c:63:19: error: result of comparison of constant 65536 with expression of type '__u16' (aka 'unsigned short') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (argv->v_size > PAGE_SIZE)
~~~~~~~~~~~~ ^ ~~~~~~~~~
This is ok, so just shut up that warning with a cast.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240328143051.1069575-7-arnd@kernel.org
Fixes: 3358b4aaa8 ("nilfs2: fix problems of memory allocation in ioctl")
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit eb85dace89 upstream.
Syzbot has reported a potential hang in nilfs_detach_log_writer() called
during nilfs2 unmount.
Analysis revealed that this is because nilfs_segctor_sync(), which
synchronizes with the log writer thread, can be called after
nilfs_segctor_destroy() terminates that thread, as shown in the call trace
below:
nilfs_detach_log_writer
nilfs_segctor_destroy
nilfs_segctor_kill_thread --> Shut down log writer thread
flush_work
nilfs_iput_work_func
nilfs_dispose_list
iput
nilfs_evict_inode
nilfs_transaction_commit
nilfs_construct_segment (if inode needs sync)
nilfs_segctor_sync --> Attempt to synchronize with
log writer thread
*** DEADLOCK ***
Fix this issue by changing nilfs_segctor_sync() so that the log writer
thread returns normally without synchronizing after it terminates, and by
forcing tasks that are already waiting to complete once after the thread
terminates.
The skipped inode metadata flushout will then be processed together in the
subsequent cleanup work in nilfs_segctor_destroy().
Link: https://lkml.kernel.org/r/20240520132621.4054-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+e3973c409251e136fdd0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e3973c409251e136fdd0
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: "Bai, Shuangpeng" <sjb7183@psu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 936184eadd upstream.
A potential and reproducible race issue has been identified where
nilfs_segctor_sync() would block even after the log writer thread writes a
checkpoint, unless there is an interrupt or other trigger to resume log
writing.
This turned out to be because, depending on the execution timing of the
log writer thread running in parallel, the log writer thread may skip
responding to nilfs_segctor_sync(), which causes a call to schedule()
waiting for completion within nilfs_segctor_sync() to lose the opportunity
to wake up.
The reason why waking up the task waiting in nilfs_segctor_sync() may be
skipped is that updating the request generation issued using a shared
sequence counter and adding an wait queue entry to the request wait queue
to the log writer, are not done atomically. There is a possibility that
log writing and request completion notification by nilfs_segctor_wakeup()
may occur between the two operations, and in that case, the wait queue
entry is not yet visible to nilfs_segctor_wakeup() and the wake-up of
nilfs_segctor_sync() will be carried over until the next request occurs.
Fix this issue by performing these two operations simultaneously within
the lock section of sc_state_lock. Also, following the memory barrier
guidelines for event waiting loops, move the call to set_current_state()
in the same location into the event waiting loop to ensure that a memory
barrier is inserted just before the event condition determination.
Link: https://lkml.kernel.org/r/20240520132621.4054-3-konishi.ryusuke@gmail.com
Fixes: 9ff05123e3 ("nilfs2: segment constructor")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: "Bai, Shuangpeng" <sjb7183@psu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c4a7dc9523 upstream.
The size of the nilfs_type_by_mode array in the fs/nilfs2/dir.c file is
defined as "S_IFMT >> S_SHIFT", but the nilfs_set_de_type() function,
which uses this array, specifies the index to read from the array in the
same way as "(mode & S_IFMT) >> S_SHIFT".
static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode
*inode)
{
umode_t mode = inode->i_mode;
de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; // oob
}
However, when the index is determined this way, an out-of-bounds (OOB)
error occurs by referring to an index that is 1 larger than the array size
when the condition "mode & S_IFMT == S_IFMT" is satisfied. Therefore, a
patch to resize the nilfs_type_by_mode array should be applied to prevent
OOB errors.
Link: https://lkml.kernel.org/r/20240415182048.7144-1-konishi.ryusuke@gmail.com
Reported-by: syzbot+2e22057de05b9f3b30d8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2e22057de05b9f3b30d8
Fixes: 2ba466d74e ("nilfs2: directory entry operations")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 269cdf353b ]
Fix a bug where nilfs_get_block() returns a successful status when
searching and inserting the specified block both fail inconsistently. If
this inconsistent behavior is not due to a previously fixed bug, then an
unexpected race is occurring, so return a temporary error -EAGAIN instead.
This prevents callers such as __block_write_begin_int() from requesting a
read into a buffer that is not mapped, which would cause the BUG_ON check
for the BH_Mapped flag in submit_bh_wbc() to fail.
Link: https://lkml.kernel.org/r/20240313105827.5296-3-konishi.ryusuke@gmail.com
Fixes: 1f5abe7e7d ("nilfs2: replace BUG_ON and BUG calls triggerable from ioctl")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a1d0747a39 ]
Add macros for nilfs_<level>(sb, fmt, ...) and convert the uses of
'nilfs_msg(sb, KERN_<LEVEL>, ...)' to 'nilfs_<level>(sb, ...)' so nilfs2
uses a logging style more like the typical kernel logging style.
Miscellanea:
o Realign arguments for these uses
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1595860111-3920-4-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 269cdf353b ("nilfs2: prevent kernel bug at submit_bh_wbc()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f2f26b4a84 ]
Patch series "nilfs2: fix kernel bug at submit_bh_wbc()".
This resolves a kernel BUG reported by syzbot. Since there are two
flaws involved, I've made each one a separate patch.
The first patch alone resolves the syzbot-reported bug, but I think
both fixes should be sent to stable, so I've tagged them as such.
This patch (of 2):
Syzbot has reported a kernel bug in submit_bh_wbc() when writing file data
to a nilfs2 file system whose metadata is corrupted.
There are two flaws involved in this issue.
The first flaw is that when nilfs_get_block() locates a data block using
btree or direct mapping, if the disk address translation routine
nilfs_dat_translate() fails with internal code -ENOENT due to DAT metadata
corruption, it can be passed back to nilfs_get_block(). This causes
nilfs_get_block() to misidentify an existing block as non-existent,
causing both data block lookup and insertion to fail inconsistently.
The second flaw is that nilfs_get_block() returns a successful status in
this inconsistent state. This causes the caller __block_write_begin_int()
or others to request a read even though the buffer is not mapped,
resulting in a BUG_ON check for the BH_Mapped flag in submit_bh_wbc()
failing.
This fixes the first issue by changing the return value to code -EINVAL
when a conversion using DAT fails with code -ENOENT, avoiding the
conflicting condition that leads to the kernel bug described above. Here,
code -EINVAL indicates that metadata corruption was detected during the
block lookup, which will be properly handled as a file system error and
converted to -EIO when passing through the nilfs2 bmap layer.
Link: https://lkml.kernel.org/r/20240313105827.5296-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20240313105827.5296-2-konishi.ryusuke@gmail.com
Fixes: c3a7abf06c ("nilfs2: support contiguous lookup of blocks")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+cfed5b56649bddf80d6e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=cfed5b56649bddf80d6e
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5124a0a549 upstream.
If DAT metadata file block access fails due to corruption of the DAT file
or abnormal virtual block numbers held by b-trees or inodes, a kernel
warning is generated.
This replaces the WARN_ONs by error output, so that a kernel, booted with
panic_on_warn, does not panic. This patch also replaces the detected
return code -ENOENT with another internal code -EINVAL to notify the bmap
layer of metadata corruption. When the bmap layer sees -EINVAL, it
handles the abnormal situation with nilfs_bmap_convert_error() and finally
returns code -EIO as it should.
Link: https://lkml.kernel.org/r/0000000000005cc3d205ea23ddcf@google.com
Link: https://lkml.kernel.org/r/20230126164114.6911-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: <syzbot+5d5d25f90f195a3cfcb4@syzkaller.appspotmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5bc09b397c upstream.
According to a syzbot report, end_buffer_async_write(), which handles the
completion of block device writes, may detect abnormal condition of the
buffer async_write flag and cause a BUG_ON failure when using nilfs2.
Nilfs2 itself does not use end_buffer_async_write(). But, the async_write
flag is now used as a marker by commit 7f42ec3941 ("nilfs2: fix issue
with race condition of competition between segments for dirty blocks") as
a means of resolving double list insertion of dirty blocks in
nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the
resulting crash.
This modification is safe as long as it is used for file data and b-tree
node blocks where the page caches are independent. However, it was
irrelevant and redundant to also introduce async_write for segment summary
and super root blocks that share buffers with the backing device. This
led to the possibility that the BUG_ON check in end_buffer_async_write
would fail as described above, if independent writebacks of the backing
device occurred in parallel.
The use of async_write for segment summary buffers has already been
removed in a previous change.
Fix this issue by removing the manipulation of the async_write flag for
the remaining super root block buffer.
Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com
Fixes: 7f42ec3941 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+5c04210f7c7f897c1e7f@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@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>
commit 38296afe3c upstream.
Syzbot reported a hang issue in migrate_pages_batch() called by mbind()
and nilfs_lookup_dirty_data_buffers() called in the log writer of nilfs2.
While migrate_pages_batch() locks a folio and waits for the writeback to
complete, the log writer thread that should bring the writeback to
completion picks up the folio being written back in
nilfs_lookup_dirty_data_buffers() that it calls for subsequent log
creation and was trying to lock the folio. Thus causing a deadlock.
In the first place, it is unexpected that folios/pages in the middle of
writeback will be updated and become dirty. Nilfs2 adds a checksum to
verify the validity of the log being written and uses it for recovery at
mount, so data changes during writeback are suppressed. Since this is
broken, an unclean shutdown could potentially cause recovery to fail.
Investigation revealed that the root cause is that the wait for writeback
completion in nilfs_page_mkwrite() is conditional, and if the backing
device does not require stable writes, data may be modified without
waiting.
Fix these issues by making nilfs_page_mkwrite() wait for writeback to
finish regardless of the stable write requirement of the backing device.
Link: https://lkml.kernel.org/r/20240131145657.4209-1-konishi.ryusuke@gmail.com
Fixes: 1d1d1a7672 ("mm: only enforce stable page writes if the backing device requires it")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+ee2ae68da3b22d04cd8d@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000047d819061004ad6c@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67b8bcbaed upstream.
The helper function nilfs_recovery_copy_block() of
nilfs_recovery_dsync_blocks(), which recovers data from logs created by
data sync writes during a mount after an unclean shutdown, incorrectly
calculates the on-page offset when copying repair data to the file's page
cache. In environments where the block size is smaller than the page
size, this flaw can cause data corruption and leak uninitialized memory
bytes during the recovery process.
Fix these issues by correcting this byte offset calculation on the page.
Link: https://lkml.kernel.org/r/20240124121936.10575-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d61d0ab573 upstream.
When mounting a filesystem image with a block size larger than the page
size, nilfs2 repeatedly outputs long error messages with stack traces to
the kernel log, such as the following:
getblk(): invalid block size 8192 requested
logical block size: 512
...
Call Trace:
dump_stack_lvl+0x92/0xd4
dump_stack+0xd/0x10
bdev_getblk+0x33a/0x354
__breadahead+0x11/0x80
nilfs_search_super_root+0xe2/0x704 [nilfs2]
load_nilfs+0x72/0x504 [nilfs2]
nilfs_mount+0x30f/0x518 [nilfs2]
legacy_get_tree+0x1b/0x40
vfs_get_tree+0x18/0xc4
path_mount+0x786/0xa88
__ia32_sys_mount+0x147/0x1a8
__do_fast_syscall_32+0x56/0xc8
do_fast_syscall_32+0x29/0x58
do_SYSENTER_32+0x15/0x18
entry_SYSENTER_32+0x98/0xf1
...
This overloads the system logger. And to make matters worse, it sometimes
crashes the kernel with a memory access violation.
This is because the return value of the sb_set_blocksize() call, which
should be checked for errors, is not checked.
The latter issue is due to out-of-buffer memory being accessed based on a
large block size that caused sb_set_blocksize() to fail for buffers read
with the initial minimum block size that remained unupdated in the
super_block structure.
Since nilfs2 mkfs tool does not accept block sizes larger than the system
page size, this has been overlooked. However, it is possible to create
this situation by intentionally modifying the tool or by passing a
filesystem image created on a system with a large page size to a system
with a smaller page size and mounting it.
Fix this issue by inserting the expected error handling for the call to
sb_set_blocksize().
Link: https://lkml.kernel.org/r/20231129141547.4726-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 675abf8df1 upstream.
If nilfs2 reads a disk image with corrupted segment usage metadata, and
its segment usage information is marked as an error for the segment at the
write location, nilfs_sufile_set_segment_usage() can trigger WARN_ONs
during log writing.
Segments newly allocated for writing with nilfs_sufile_alloc() will not
have this error flag set, but this unexpected situation will occur if the
segment indexed by either nilfs->ns_segnum or nilfs->ns_nextnum (active
segment) was marked in error.
Fix this issue by inserting a sanity check to treat it as a file system
corruption.
Since error returns are not allowed during the execution phase where
nilfs_sufile_set_segment_usage() is used, this inserts the sanity check
into nilfs_sufile_mark_dirty() which pre-reads the buffer containing the
segment usage record to be updated and sets it up in a dirty state for
writing.
In addition, nilfs_sufile_set_segment_usage() is also called when
canceling log writing and undoing segment usage update, so in order to
avoid issuing the same kernel warning in that case, in case of
cancellation, avoid checking the error flag in
nilfs_sufile_set_segment_usage().
Link: https://lkml.kernel.org/r/20231205085947.4431-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+14e9f834f6ddecece094@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=14e9f834f6ddecece094
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7ee29facd8 upstream.
In nilfs_gccache_submit_read_data(), brelse(bh) is called to drop the
reference count of bh when the call to nilfs_dat_translate() fails. If
the reference count hits 0 and its owner page gets unlocked, bh may be
freed. However, bh->b_page is dereferenced to put the page after that,
which may result in a use-after-free bug. This patch moves the release
operation after unlocking and putting the page.
NOTE: The function in question is only called in GC, and in combination
with current userland tools, address translation using DAT does not occur
in that function, so the code path that causes this issue will not be
executed. However, it is possible to run that code path by intentionally
modifying the userland GC library or by calling the GC ioctl directly.
[konishi.ryusuke@gmail.com: NOTE added to the commit log]
Link: https://lkml.kernel.org/r/1543201709-53191-1-git-send-email-bianpan2016@163.com
Link: https://lkml.kernel.org/r/20230921141731.10073-1-konishi.ryusuke@gmail.com
Fixes: a3d93f709e ("nilfs2: block cache for garbage collection")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Reported-by: Ferry Meng <mengferry@linux.alibaba.com>
Closes: https://lkml.kernel.org/r/20230818092022.111054-1-mengferry@linux.alibaba.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cdaac8e7e5 upstream.
A syzbot stress test using a corrupted disk image reported that
mark_buffer_dirty() called from __nilfs_mark_inode_dirty() or
nilfs_palloc_commit_alloc_entry() may output a kernel warning, and can
panic if the kernel is booted with panic_on_warn.
This is because nilfs2 keeps buffer pointers in local structures for some
metadata and reuses them, but such buffers may be forcibly discarded by
nilfs_clear_dirty_page() in some critical situations.
This issue is reported to appear after commit 28a65b49eb ("nilfs2: do
not write dirty data after degenerating to read-only"), but the issue has
potentially existed before.
Fix this issue by checking the uptodate flag when attempting to reuse an
internally held buffer, and reloading the metadata instead of reusing the
buffer if the flag was lost.
Link: https://lkml.kernel.org/r/20230818131804.7758-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+cdfcae656bac88ba0e2d@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/0000000000003da75f05fdeffd12@google.com
Fixes: 8c26c4e269 ("nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption")
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f83913f8c5 upstream.
A syzbot stress test reported that create_empty_buffers() called from
nilfs_lookup_dirty_data_buffers() can cause a general protection fault.
Analysis using its reproducer revealed that the back reference "mapping"
from a page/folio has been changed to NULL after dirty page/folio gang
lookup in nilfs_lookup_dirty_data_buffers().
Fix this issue by excluding pages/folios from being collected if, after
acquiring a lock on each page/folio, its back reference "mapping" differs
from the pointer to the address space struct that held the page/folio.
Link: https://lkml.kernel.org/r/20230805132038.6435-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/0000000000002930a705fc32b231@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f8654743a0 upstream.
During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer(). Previously,
nilfs_evict_inode() could cause use-after-free read for nilfs_root if
inodes are left in "garbage_list" and released by nilfs_dispose_list at
the end of nilfs_detach_log_writer(), and this bug was fixed by commit
9b5a04ac3a ("nilfs2: fix use-after-free bug of nilfs_root in
nilfs_evict_inode()").
However, it turned out that there is another possibility of UAF in the
call path where mark_inode_dirty_sync() is called from iput():
nilfs_detach_log_writer()
nilfs_dispose_list()
iput()
mark_inode_dirty_sync()
__mark_inode_dirty()
nilfs_dirty_inode()
__nilfs_mark_inode_dirty()
nilfs_load_inode_block() --> causes UAF of nilfs_root struct
This can happen after commit 0ae45f63d4 ("vfs: add support for a
lazytime mount option"), which changed iput() to call
mark_inode_dirty_sync() on its final reference if i_state has I_DIRTY_TIME
flag and i_nlink is non-zero.
This issue appears after commit 28a65b49eb ("nilfs2: do not write dirty
data after degenerating to read-only") when using the syzbot reproducer,
but the issue has potentially existed before.
Fix this issue by adding a "purging flag" to the nilfs structure, setting
that flag while disposing the "garbage_list" and checking it in
__nilfs_mark_inode_dirty().
Unlike commit 9b5a04ac3a ("nilfs2: fix use-after-free bug of nilfs_root
in nilfs_evict_inode()"), this patch does not rely on ns_writer to
determine whether to skip operations, so as not to break recovery on
mount. The nilfs_salvage_orphan_logs routine dirties the buffer of
salvaged data before attaching the log writer, so changing
__nilfs_mark_inode_dirty() to skip the operation when ns_writer is NULL
will cause recovery write to fail. The purpose of using the cleanup-only
flag is to allow for narrowing of such conditions.
Link: https://lkml.kernel.org/r/20230728191318.33047-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+74db8b3087f293d3a13a@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/000000000000b4e906060113fd63@google.com
Fixes: 0ae45f63d4 ("vfs: add support for a lazytime mount option")
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org> # 4.0+
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 782e53d0c1 upstream.
In a syzbot stress test that deliberately causes file system errors on
nilfs2 with a corrupted disk image, it has been reported that
nilfs_clear_dirty_page() called from nilfs_clear_dirty_pages() can cause a
general protection fault.
In nilfs_clear_dirty_pages(), when looking up dirty pages from the page
cache and calling nilfs_clear_dirty_page() for each dirty page/folio
retrieved, the back reference from the argument page to "mapping" may have
been changed to NULL (and possibly others). It is necessary to check this
after locking the page/folio.
So, fix this issue by not calling nilfs_clear_dirty_page() on a page/folio
after locking it in nilfs_clear_dirty_pages() if the back reference
"mapping" from the page/folio is different from the "mapping" that held
the page/folio just before.
Link: https://lkml.kernel.org/r/20230612021456.3682-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+53369d11851d8f26735c@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/000000000000da4f6b05eb9bf593@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 679bd7ebdd upstream.
As a result of analysis of a syzbot report, it turned out that in three
cases where nilfs2 allocates block device buffers directly via sb_getblk,
concurrent reads to the device can corrupt the allocated buffers.
Nilfs2 uses sb_getblk for segment summary blocks, that make up a log
header, and the super root block, that is the trailer, and when moving and
writing the second super block after fs resize.
In any of these, since the uptodate flag is not set when storing metadata
to be written in the allocated buffers, the stored metadata will be
overwritten if a device read of the same block occurs concurrently before
the write. This causes metadata corruption and misbehavior in the log
write itself, causing warnings in nilfs_btree_assign() as reported.
Fix these issues by setting an uptodate flag on the buffer head on the
first or before modifying each buffer obtained with sb_getblk, and
clearing the flag on failure.
When setting the uptodate flag, the lock_buffer/unlock_buffer pair is used
to perform necessary exclusive control, and the buffer is filled to ensure
that uninitialized bytes are not mixed into the data read from others. As
for buffers for segment summary blocks, they are filled incrementally, so
if the uptodate flag was unset on their allocation, set the flag and zero
fill the buffer once at that point.
Also, regarding the superblock move routine, the starting point of the
memset call to zerofill the block is incorrectly specified, which can
cause a buffer overflow on file systems with block sizes greater than
4KiB. In addition, if the superblock is moved within a large block, it is
necessary to assume the possibility that the data in the superblock will
be destroyed by zero-filling before copying. So fix these potential
issues as well.
Link: https://lkml.kernel.org/r/20230609035732.20426-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+31837fe952932efc8fb9@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000030000a05e981f475@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 92c5d1b860 upstream.
The current sanity check for nilfs2 geometry information lacks checks for
the number of segments stored in superblocks, so even for device images
that have been destructively truncated or have an unusually high number of
segments, the mount operation may succeed.
This causes out-of-bounds block I/O on file system block reads or log
writes to the segments, the latter in particular causing
"a_ops->writepages" to repeatedly fail, resulting in sync_inodes_sb() to
hang.
Fix this issue by checking the number of segments stored in the superblock
and avoiding mounting devices that can cause out-of-bounds accesses. To
eliminate the possibility of overflow when calculating the number of
blocks required for the device from the number of segments, this also adds
a helper function to calculate the upper bound on the number of segments
and inserts a check using it.
Link: https://lkml.kernel.org/r/20230526021332.3431-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+7d50f1e54a12ba3aeae2@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=7d50f1e54a12ba3aeae2
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fee5eaecca upstream.
Syzbot reports that in its stress test for resize ioctl, the log writing
function nilfs_segctor_do_construct hits a WARN_ON in
nilfs_segctor_truncate_segments().
It turned out that there is a problem with the current implementation of
the resize ioctl, which changes the writable range on the device (the
range of allocatable segments) at the end of the resize process.
This order is necessary for file system expansion to avoid corrupting the
superblock at trailing edge. However, in the case of a file system
shrink, if log writes occur after truncating out-of-bounds trailing
segments and before the resize is complete, segments may be allocated from
the truncated space.
The userspace resize tool was fine as it limits the range of allocatable
segments before performing the resize, but it can run into this issue if
the resize ioctl is called alone.
Fix this issue by changing nilfs_sufile_resize() to update the range of
allocatable segments immediately after successful truncation of segment
space in case of file system shrink.
Link: https://lkml.kernel.org/r/20230524094348.3784-1-konishi.ryusuke@gmail.com
Fixes: 4e33f9eab0 ("nilfs2: implement resize ioctl")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+33494cd0df2ec2931851@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/0000000000005434c405fbbafdc5@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2f012f2bac upstream.
A syzbot fault injection test reported that nilfs_btnode_create_block, a
helper function that allocates a new node block for b-trees, causes a
kernel BUG for disk images where the file system block size is smaller
than the page size.
This was due to unexpected flags on the newly allocated buffer head, and
it turned out to be because the buffer flags were not cleared by
nilfs_btnode_abort_change_key() after an error occurred during a b-tree
update operation and the buffer was later reused in that state.
Fix this issue by using nilfs_btnode_delete() to abandon the unused
preallocated buffer in nilfs_btnode_abort_change_key().
Link: https://lkml.kernel.org/r/20230513102428.10223-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+b0a35a5c1f7e846d3b09@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/000000000000d1d6c205ebc4d512@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9b5a04ac3a upstream.
During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer(). However, since
nilfs_evict_inode() uses nilfs_root for some cleanup operations, it may
cause use-after-free read if inodes are left in "garbage_list" and
released by nilfs_dispose_list() at the end of nilfs_detach_log_writer().
Fix this issue by modifying nilfs_evict_inode() to only clear inode
without additional metadata changes that use nilfs_root if the file system
is degraded to read-only or the writer is detached.
Link: https://lkml.kernel.org/r/20230509152956.8313-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+78d4495558999f55d1da@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000099e5ac05fb1c3b85@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a6a491c048 upstream.
If the disk image that nilfs2 mounts is corrupted and a virtual block
address obtained by block lookup for a metadata file is invalid,
nilfs_bmap_lookup_at_level() may return the same internal return code as
-ENOENT, meaning the block does not exist in the metadata file.
This duplication of return codes confuses nilfs_mdt_get_block(), causing
it to read and create a metadata block indefinitely.
In particular, if this happens to the inode metadata file, ifile,
semaphore i_rwsem can be left held, causing task hangs in lock_mount.
Fix this issue by making nilfs_bmap_lookup_at_level() treat virtual block
address translation failures with -ENOENT as metadata corruption instead
of returning the error code.
Link: https://lkml.kernel.org/r/20230430193046.6769-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+221d75710bde87fa0e97@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=221d75710bde87fa0e97
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 28a65b49eb upstream.
According to syzbot's report, mark_buffer_dirty() called from
nilfs_segctor_do_construct() outputs a warning with some patterns after
nilfs2 detects metadata corruption and degrades to read-only mode.
After such read-only degeneration, page cache data may be cleared through
nilfs_clear_dirty_page() which may also clear the uptodate flag for their
buffer heads. However, even after the degeneration, log writes are still
performed by unmount processing etc., which causes mark_buffer_dirty() to
be called for buffer heads without the "uptodate" flag and causes the
warning.
Since any writes should not be done to a read-only file system in the
first place, this fixes the warning in mark_buffer_dirty() by letting
nilfs_segctor_do_construct() abort early if in read-only mode.
This also changes the retry check of nilfs_segctor_write_out() to avoid
unnecessary log write retries if it detects -EROFS that
nilfs_segctor_do_construct() returned.
Link: https://lkml.kernel.org/r/20230427011526.13457-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+2af3bc9585be7f23f290@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=2af3bc9585be7f23f290
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef832747a8 upstream.
Syzbot still reports uninit-value in nilfs_add_checksums_on_logs() for
KMSAN enabled kernels after applying commit 7397031622 ("nilfs2:
initialize "struct nilfs_binfo_dat"->bi_pad field").
This is because the unused bytes at the end of each block in segment
summaries are not initialized. So this fixes the issue by padding the
unused bytes with null bytes.
Link: https://lkml.kernel.org/r/20230417173513.12598-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+048585f3f4227bb2b49b@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=048585f3f4227bb2b49b
Cc: Alexander Potapenko <glider@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>
commit 42560f9c92 upstream.
The current nilfs2 sysfs support has issues with the timing of creation
and deletion of sysfs entries, potentially leading to null pointer
dereferences, use-after-free, and lockdep warnings.
Some of the sysfs attributes for nilfs2 per-filesystem instance refer to
metadata file "cpfile", "sufile", or "dat", but
nilfs_sysfs_create_device_group that creates those attributes is executed
before the inodes for these metadata files are loaded, and
nilfs_sysfs_delete_device_group which deletes these sysfs entries is
called after releasing their metadata file inodes.
Therefore, access to some of these sysfs attributes may occur outside of
the lifetime of these metadata files, resulting in inode NULL pointer
dereferences or use-after-free.
In addition, the call to nilfs_sysfs_create_device_group() is made during
the locking period of the semaphore "ns_sem" of nilfs object, so the
shrinker call caused by the memory allocation for the sysfs entries, may
derive lock dependencies "ns_sem" -> (shrinker) -> "locks acquired in
nilfs_evict_inode()".
Since nilfs2 may acquire "ns_sem" deep in the call stack holding other
locks via its error handler __nilfs_error(), this causes lockdep to report
circular locking. This is a false positive and no circular locking
actually occurs as no inodes exist yet when
nilfs_sysfs_create_device_group() is called. Fortunately, the lockdep
warnings can be resolved by simply moving the call to
nilfs_sysfs_create_device_group() out of "ns_sem".
This fixes these sysfs issues by revising where the device's sysfs
interface is created/deleted and keeping its lifetime within the lifetime
of the metadata files above.
Link: https://lkml.kernel.org/r/20230330205515.6167-1-konishi.ryusuke@gmail.com
Fixes: dd70edbde2 ("nilfs2: integrate sysfs support into driver")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+979fa7f9c0d086fdc282@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/0000000000003414b505f7885f7e@google.com
Reported-by: syzbot+5b7d542076d9bddc3c6a@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/0000000000006ac86605f5f44eb9@google.com
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6be49d100c upstream.
The finalization of nilfs_segctor_thread() can race with
nilfs_segctor_kill_thread() which terminates that thread, potentially
causing a use-after-free BUG as KASAN detected.
At the end of nilfs_segctor_thread(), it assigns NULL to "sc_task" member
of "struct nilfs_sc_info" to indicate the thread has finished, and then
notifies nilfs_segctor_kill_thread() of this using waitqueue
"sc_wait_task" on the struct nilfs_sc_info.
However, here, immediately after the NULL assignment to "sc_task", it is
possible that nilfs_segctor_kill_thread() will detect it and return to
continue the deallocation, freeing the nilfs_sc_info structure before the
thread does the notification.
This fixes the issue by protecting the NULL assignment to "sc_task" and
its notification, with spinlock "sc_state_lock" of the struct
nilfs_sc_info. Since nilfs_segctor_kill_thread() does a final check to
see if "sc_task" is NULL with "sc_state_lock" locked, this can eliminate
the race.
Link: https://lkml.kernel.org/r/20230327175318.8060-1-konishi.ryusuke@gmail.com
Reported-by: syzbot+b08ebcc22f8f3e6be43a@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/00000000000000660d05f7dfa877@google.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0035870002 upstream.
The ioctl helper function nilfs_ioctl_wrap_copy(), which exchanges a
metadata array to/from user space, may copy uninitialized buffer regions
to user space memory for read-only ioctl commands NILFS_IOCTL_GET_SUINFO
and NILFS_IOCTL_GET_CPINFO.
This can occur when the element size of the user space metadata given by
the v_size member of the argument nilfs_argv structure is larger than the
size of the metadata element (nilfs_suinfo structure or nilfs_cpinfo
structure) on the file system side.
KMSAN-enabled kernels detect this issue as follows:
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user
include/linux/instrumented.h:121 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xc0/0x100 lib/usercopy.c:33
instrument_copy_to_user include/linux/instrumented.h:121 [inline]
_copy_to_user+0xc0/0x100 lib/usercopy.c:33
copy_to_user include/linux/uaccess.h:169 [inline]
nilfs_ioctl_wrap_copy+0x6fa/0xc10 fs/nilfs2/ioctl.c:99
nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline]
nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290
nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343
__do_compat_sys_ioctl fs/ioctl.c:968 [inline]
__se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910
__ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82
Uninit was created at:
__alloc_pages+0x9f6/0xe90 mm/page_alloc.c:5572
alloc_pages+0xab0/0xd80 mm/mempolicy.c:2287
__get_free_pages+0x34/0xc0 mm/page_alloc.c:5599
nilfs_ioctl_wrap_copy+0x223/0xc10 fs/nilfs2/ioctl.c:74
nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline]
nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290
nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343
__do_compat_sys_ioctl fs/ioctl.c:968 [inline]
__se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910
__ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82
Bytes 16-127 of 3968 are uninitialized
...
This eliminates the leak issue by initializing the page allocated as
buffer using get_zeroed_page().
Link: https://lkml.kernel.org/r/20230307085548.6290-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+132fdd2f1e1805fdc591@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/000000000000a5bd2d05f63f04ae@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 99b9402a36 upstream.
Macro NILFS_SB2_OFFSET_BYTES, which computes the position of the second
superblock, underflows when the argument device size is less than 4096
bytes. Therefore, when using this macro, it is necessary to check in
advance that the device size is not less than a lower limit, or at least
that underflow does not occur.
The current nilfs2 implementation lacks this check, causing out-of-bound
block access when mounting devices smaller than 4096 bytes:
I/O error, dev loop0, sector 36028797018963960 op 0x0:(READ) flags 0x0
phys_seg 1 prio class 2
NILFS (loop0): unable to read secondary superblock (blocksize = 1024)
In addition, when trying to resize the filesystem to a size below 4096
bytes, this underflow occurs in nilfs_resize_fs(), passing a huge number
of segments to nilfs_sufile_resize(), corrupting parameters such as the
number of segments in superblocks. This causes excessive loop iterations
in nilfs_sufile_resize() during a subsequent resize ioctl, causing
semaphore ns_segctor_sem to block for a long time and hang the writer
thread:
INFO: task segctord:5067 blocked for more than 143 seconds.
Not tainted 6.2.0-rc8-syzkaller-00015-gf6feea56f66d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:segctord state:D stack:23456 pid:5067 ppid:2
flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5293 [inline]
__schedule+0x1409/0x43f0 kernel/sched/core.c:6606
schedule+0xc3/0x190 kernel/sched/core.c:6682
rwsem_down_write_slowpath+0xfcf/0x14a0 kernel/locking/rwsem.c:1190
nilfs_transaction_lock+0x25c/0x4f0 fs/nilfs2/segment.c:357
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2486 [inline]
nilfs_segctor_thread+0x52f/0x1140 fs/nilfs2/segment.c:2570
kthread+0x270/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
...
Call Trace:
<TASK>
folio_mark_accessed+0x51c/0xf00 mm/swap.c:515
__nilfs_get_page_block fs/nilfs2/page.c:42 [inline]
nilfs_grab_buffer+0x3d3/0x540 fs/nilfs2/page.c:61
nilfs_mdt_submit_block+0xd7/0x8f0 fs/nilfs2/mdt.c:121
nilfs_mdt_read_block+0xeb/0x430 fs/nilfs2/mdt.c:176
nilfs_mdt_get_block+0x12d/0xbb0 fs/nilfs2/mdt.c:251
nilfs_sufile_get_segment_usage_block fs/nilfs2/sufile.c:92 [inline]
nilfs_sufile_truncate_range fs/nilfs2/sufile.c:679 [inline]
nilfs_sufile_resize+0x7a3/0x12b0 fs/nilfs2/sufile.c:777
nilfs_resize_fs+0x20c/0xed0 fs/nilfs2/super.c:422
nilfs_ioctl_resize fs/nilfs2/ioctl.c:1033 [inline]
nilfs_ioctl+0x137c/0x2440 fs/nilfs2/ioctl.c:1301
...
This fixes these issues by inserting appropriate minimum device size
checks or anti-underflow checks, depending on where the macro is used.
Link: https://lkml.kernel.org/r/0000000000004e1dfa05f4a48e6b@google.com
Link: https://lkml.kernel.org/r/20230214224043.24141-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: <syzbot+f0c4082ce5ebebdac63b@syzkaller.appspotmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7633355e5c upstream.
If nilfs2 reads a corrupted disk image and tries to reads a b-tree node
block by calling __nilfs_btree_get_block() against an invalid virtual
block address, it returns -ENOENT because conversion of the virtual block
address to a disk block address fails. However, this return value is the
same as the internal code that b-tree lookup routines return to indicate
that the block being searched does not exist, so functions that operate on
that b-tree may misbehave.
When nilfs_btree_insert() receives this spurious 'not found' code from
nilfs_btree_do_lookup(), it misunderstands that the 'not found' check was
successful and continues the insert operation using incomplete lookup path
data, causing the following crash:
general protection fault, probably for non-canonical address
0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
...
RIP: 0010:nilfs_btree_get_nonroot_node fs/nilfs2/btree.c:418 [inline]
RIP: 0010:nilfs_btree_prepare_insert fs/nilfs2/btree.c:1077 [inline]
RIP: 0010:nilfs_btree_insert+0x6d3/0x1c10 fs/nilfs2/btree.c:1238
Code: bc 24 80 00 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89
ff e8 4b 02 92 fe 4d 8b 3f 49 83 c7 28 4c 89 f8 48 c1 e8 03 <42> 80 3c
28 00 74 08 4c 89 ff e8 2e 02 92 fe 4d 8b 3f 49 83 c7 02
...
Call Trace:
<TASK>
nilfs_bmap_do_insert fs/nilfs2/bmap.c:121 [inline]
nilfs_bmap_insert+0x20d/0x360 fs/nilfs2/bmap.c:147
nilfs_get_block+0x414/0x8d0 fs/nilfs2/inode.c:101
__block_write_begin_int+0x54c/0x1a80 fs/buffer.c:1991
__block_write_begin fs/buffer.c:2041 [inline]
block_write_begin+0x93/0x1e0 fs/buffer.c:2102
nilfs_write_begin+0x9c/0x110 fs/nilfs2/inode.c:261
generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772
__generic_file_write_iter+0x176/0x400 mm/filemap.c:3900
generic_file_write_iter+0xab/0x310 mm/filemap.c:3932
call_write_iter include/linux/fs.h:2186 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x7dc/0xc50 fs/read_write.c:584
ksys_write+0x177/0x2a0 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
...
</TASK>
This patch fixes the root cause of this problem by replacing the error
code that __nilfs_btree_get_block() returns on block address conversion
failure from -ENOENT to another internal code -EINVAL which means that the
b-tree metadata is corrupted.
By returning -EINVAL, it propagates without glitches, and for all relevant
b-tree operations, functions in the upper bmap layer output an error
message indicating corrupted b-tree metadata via
nilfs_bmap_convert_error(), and code -EIO will be eventually returned as
it should be.
Link: https://lkml.kernel.org/r/000000000000bd89e205f0e38355@google.com
Link: https://lkml.kernel.org/r/20230105055356.8811-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+ede796cecd5296353515@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 610a2a3d7d ]
Patch series "nilfs2: fix UBSAN shift-out-of-bounds warnings on mount
time".
The first patch fixes a bug reported by syzbot, and the second one fixes
the remaining bug of the same kind. Although they are triggered by the
same super block data anomaly, I divided it into the above two because the
details of the issues and how to fix it are different.
Both are required to eliminate the shift-out-of-bounds issues at mount
time.
This patch (of 2):
If the block size exponent information written in an on-disk superblock is
corrupted, nilfs_sb2_bad_offset helper function can trigger
shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn
is set):
shift exponent 38983 is too large for 64-bit type 'unsigned long long'
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322
nilfs_sb2_bad_offset fs/nilfs2/the_nilfs.c:449 [inline]
nilfs_load_super_block+0xdf5/0xe00 fs/nilfs2/the_nilfs.c:523
init_nilfs+0xb7/0x7d0 fs/nilfs2/the_nilfs.c:577
nilfs_fill_super+0xb1/0x5d0 fs/nilfs2/super.c:1047
nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317
...
In addition, since nilfs_sb2_bad_offset() performs multiplication without
considering the upper bound, the computation may overflow if the disk
layout parameters are not normal.
This fixes these issues by inserting preliminary sanity checks for those
parameters and by converting the comparison from one involving
multiplication and left bit-shifting to one using division and right
bit-shifting.
Link: https://lkml.kernel.org/r/20221027044306.42774-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20221027044306.42774-2-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+e91619dd4c11c4960706@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f0a0ccda18 upstream.
Syzbot reported a null-ptr-deref bug:
NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP
frequency < 30 seconds
general protection fault, probably for non-canonical address
0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 1 PID: 3603 Comm: segctord Not tainted
6.1.0-rc2-syzkaller-00105-gb229b6ca5abb #0
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google
10/11/2022
RIP: 0010:nilfs_palloc_commit_free_entry+0xe5/0x6b0
fs/nilfs2/alloc.c:608
Code: 00 00 00 00 fc ff df 80 3c 02 00 0f 85 cd 05 00 00 48 b8 00 00 00
00 00 fc ff df 4c 8b 73 08 49 8d 7e 10 48 89 fa 48 c1 ea 03 <80> 3c 02
00 0f 85 26 05 00 00 49 8b 46 10 be a6 00 00 00 48 c7 c7
RSP: 0018:ffffc90003dff830 EFLAGS: 00010212
RAX: dffffc0000000000 RBX: ffff88802594e218 RCX: 000000000000000d
RDX: 0000000000000002 RSI: 0000000000002000 RDI: 0000000000000010
RBP: ffff888071880222 R08: 0000000000000005 R09: 000000000000003f
R10: 000000000000000d R11: 0000000000000000 R12: ffff888071880158
R13: ffff88802594e220 R14: 0000000000000000 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb1c08316a8 CR3: 0000000018560000 CR4: 0000000000350ee0
Call Trace:
<TASK>
nilfs_dat_commit_free fs/nilfs2/dat.c:114 [inline]
nilfs_dat_commit_end+0x464/0x5f0 fs/nilfs2/dat.c:193
nilfs_dat_commit_update+0x26/0x40 fs/nilfs2/dat.c:236
nilfs_btree_commit_update_v+0x87/0x4a0 fs/nilfs2/btree.c:1940
nilfs_btree_commit_propagate_v fs/nilfs2/btree.c:2016 [inline]
nilfs_btree_propagate_v fs/nilfs2/btree.c:2046 [inline]
nilfs_btree_propagate+0xa00/0xd60 fs/nilfs2/btree.c:2088
nilfs_bmap_propagate+0x73/0x170 fs/nilfs2/bmap.c:337
nilfs_collect_file_data+0x45/0xd0 fs/nilfs2/segment.c:568
nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1018
nilfs_segctor_scan_file+0x3f4/0x6f0 fs/nilfs2/segment.c:1067
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1197 [inline]
nilfs_segctor_collect fs/nilfs2/segment.c:1503 [inline]
nilfs_segctor_do_construct+0x12fc/0x6af0 fs/nilfs2/segment.c:2045
nilfs_segctor_construct+0x8e3/0xb30 fs/nilfs2/segment.c:2379
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2487 [inline]
nilfs_segctor_thread+0x3c3/0xf30 fs/nilfs2/segment.c:2570
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
...
If DAT metadata file is corrupted on disk, there is a case where
req->pr_desc_bh is NULL and blocknr is 0 at nilfs_dat_commit_end() during
a b-tree operation that cascadingly updates ancestor nodes of the b-tree,
because nilfs_dat_commit_alloc() for a lower level block can initialize
the blocknr on the same DAT entry between nilfs_dat_prepare_end() and
nilfs_dat_commit_end().
If this happens, nilfs_dat_commit_end() calls nilfs_dat_commit_free()
without valid buffer heads in req->pr_desc_bh and req->pr_bitmap_bh, and
causes the NULL pointer dereference above in
nilfs_palloc_commit_free_entry() function, which leads to a crash.
Fix this by adding a NULL check on req->pr_desc_bh and req->pr_bitmap_bh
before nilfs_palloc_commit_free_entry() in nilfs_dat_commit_free().
This also calls nilfs_error() in that case to notify that there is a fatal
flaw in the filesystem metadata and prevent further operations.
Link: https://lkml.kernel.org/r/00000000000097c20205ebaea3d6@google.com
Link: https://lkml.kernel.org/r/20221114040441.1649940-1-zhangpeng362@huawei.com
Link: https://lkml.kernel.org/r/20221119120542.17204-1-konishi.ryusuke@gmail.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+ebe05ee8e98f755f61d0@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 512c5ca01a upstream.
When extending segments, nilfs_sufile_alloc() is called to get an
unassigned segment, then mark it as dirty to avoid accidentally allocating
the same segment in the future.
But for some special cases such as a corrupted image it can be unreliable.
If such corruption of the dirty state of the segment occurs, nilfs2 may
reallocate a segment that is in use and pick the same segment for writing
twice at the same time.
This will cause the problem reported by syzkaller:
https://syzkaller.appspot.com/bug?id=c7c4748e11ffcc367cef04f76e02e931833cbd24
This case started with segbuf1.segnum = 3, nextnum = 4 when constructed.
It supposed segment 4 has already been allocated and marked as dirty.
However the dirty state was corrupted and segment 4 usage was not dirty.
For the first time nilfs_segctor_extend_segments() segment 4 was allocated
again, which made segbuf2 and next segbuf3 had same segment 4.
sb_getblk() will get same bh for segbuf2 and segbuf3, and this bh is added
to both buffer lists of two segbuf. It makes the lists broken which
causes NULL pointer dereference.
Fix the problem by setting usage as dirty every time in
nilfs_sufile_mark_dirty(), which is called during constructing current
segment to be written out and before allocating next segment.
[chenzhongjin@huawei.com: add lock protection per Ryusuke]
Link: https://lkml.kernel.org/r/20221121091141.214703-1-chenzhongjin@huawei.com
Link: https://lkml.kernel.org/r/20221118063304.140187-1-chenzhongjin@huawei.com
Fixes: 9ff05123e3 ("nilfs2: segment constructor")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reported-by: <syzbot+77e4f0...@syzkaller.appspotmail.com>
Reported-by: Liu Shixin <liushixin2@huawei.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8cccf05fe8 upstream.
If a nilfs2 filesystem is downgraded to read-only due to metadata
corruption on disk and is remounted read/write, or if emergency read-only
remount is performed, detaching a log writer and synchronizing the
filesystem can be done at the same time.
In these cases, use-after-free of the log writer (hereinafter
nilfs->ns_writer) can happen as shown in the scenario below:
Task1 Task2
-------------------------------- ------------------------------
nilfs_construct_segment
nilfs_segctor_sync
init_wait
init_waitqueue_entry
add_wait_queue
schedule
nilfs_remount (R/W remount case)
nilfs_attach_log_writer
nilfs_detach_log_writer
nilfs_segctor_destroy
kfree
finish_wait
_raw_spin_lock_irqsave
__raw_spin_lock_irqsave
do_raw_spin_lock
debug_spin_lock_before <-- use-after-free
While Task1 is sleeping, nilfs->ns_writer is freed by Task2. After Task1
waked up, Task1 accesses nilfs->ns_writer which is already freed. This
scenario diagram is based on the Shigeru Yoshida's post [1].
This patch fixes the issue by not detaching nilfs->ns_writer on remount so
that this UAF race doesn't happen. Along with this change, this patch
also inserts a few necessary read-only checks with superblock instance
where only the ns_writer pointer was used to check if the filesystem is
read-only.
Link: https://syzkaller.appspot.com/bug?id=79a4c002e960419ca173d55e863bd09e8112df8b
Link: https://lkml.kernel.org/r/20221103141759.1836312-1-syoshida@redhat.com [1]
Link: https://lkml.kernel.org/r/20221104142959.28296-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+f816fa82f8783f7a02bb@syzkaller.appspotmail.com
Reported-by: Shigeru Yoshida <syoshida@redhat.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8ac932a492 upstream.
A semaphore deadlock can occur if nilfs_get_block() detects metadata
corruption while locating data blocks and a superblock writeback occurs at
the same time:
task 1 task 2
------ ------
* A file operation *
nilfs_truncate()
nilfs_get_block()
down_read(rwsem A) <--
nilfs_bmap_lookup_contig()
... generic_shutdown_super()
nilfs_put_super()
* Prepare to write superblock *
down_write(rwsem B) <--
nilfs_cleanup_super()
* Detect b-tree corruption * nilfs_set_log_cursor()
nilfs_bmap_convert_error() nilfs_count_free_blocks()
__nilfs_error() down_read(rwsem A) <--
nilfs_set_error()
down_write(rwsem B) <--
*** DEADLOCK ***
Here, nilfs_get_block() readlocks rwsem A (= NILFS_MDT(dat_inode)->mi_sem)
and then calls nilfs_bmap_lookup_contig(), but if it fails due to metadata
corruption, __nilfs_error() is called from nilfs_bmap_convert_error()
inside the lock section.
Since __nilfs_error() calls nilfs_set_error() unless the filesystem is
read-only and nilfs_set_error() attempts to writelock rwsem B (=
nilfs->ns_sem) to write back superblock exclusively, hierarchical lock
acquisition occurs in the order rwsem A -> rwsem B.
Now, if another task starts updating the superblock, it may writelock
rwsem B during the lock sequence above, and can deadlock trying to
readlock rwsem A in nilfs_count_free_blocks().
However, there is actually no need to take rwsem A in
nilfs_count_free_blocks() because it, within the lock section, only reads
a single integer data on a shared struct with
nilfs_sufile_get_ncleansegs(). This has been the case after commit
aa474a2201 ("nilfs2: add local variable to cache the number of clean
segments"), that is, even before this bug was introduced.
So, this resolves the deadlock problem by just not taking the semaphore in
nilfs_count_free_blocks().
Link: https://lkml.kernel.org/r/20221029044912.9139-1-konishi.ryusuke@gmail.com
Fixes: e828949e5b ("nilfs2: call nilfs_error inside bmap routines")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+45d6ce7b7ad7ef455d03@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org> [2.6.38+
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d325dc6eb7 upstream.
If the beginning of the inode bitmap area is corrupted on disk, an inode
with the same inode number as the root inode can be allocated and fail
soon after. In this case, the subsequent call to nilfs_clear_inode() on
that bogus root inode will wrongly decrement the reference counter of
struct nilfs_root, and this will erroneously free struct nilfs_root,
causing kernel oopses.
This fixes the problem by changing nilfs_new_inode() to skip reserved
inode numbers while repairing the inode bitmap.
Link: https://lkml.kernel.org/r/20221003150519.39789-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+b8c672b0e22615c80fe0@syzkaller.appspotmail.com
Reported-by: Khalid Masum <khalid.masum.92@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 723ac75120 upstream.
If creation or finalization of a checkpoint fails due to anomalies in the
checkpoint metadata on disk, a kernel warning is generated.
This patch replaces the WARN_ONs by nilfs_error, so that a kernel, booted
with panic_on_warn, does not panic. A nilfs_error is appropriate here to
handle the abnormal filesystem condition.
This also replaces the detected error codes with an I/O error so that
neither of the internal error codes is returned to callers.
Link: https://lkml.kernel.org/r/20220929123330.19658-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+fbb3e0b24e8dae5a16ee@syzkaller.appspotmail.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d0d51a9706 upstream.
If nilfs_attach_log_writer() failed to create a log writer thread, it
frees a data structure of the log writer without any cleanup. After
commit e912a5b668 ("nilfs2: use root object to get ifile"), this causes
a leak of struct nilfs_root, which started to leak an ifile metadata inode
and a kobject on that struct.
In addition, if the kernel is booted with panic_on_warn, the above
ifile metadata inode leak will cause the following panic when the
nilfs2 kernel module is removed:
kmem_cache_destroy nilfs2_inode_cache: Slab cache still has objects when
called from nilfs_destroy_cachep+0x16/0x3a [nilfs2]
WARNING: CPU: 8 PID: 1464 at mm/slab_common.c:494 kmem_cache_destroy+0x138/0x140
...
RIP: 0010:kmem_cache_destroy+0x138/0x140
Code: 00 20 00 00 e8 a9 55 d8 ff e9 76 ff ff ff 48 8b 53 60 48 c7 c6 20 70 65 86 48 c7 c7 d8 69 9c 86 48 8b 4c 24 28 e8 ef 71 c7 00 <0f> 0b e9 53 ff ff ff c3 48 81 ff ff 0f 00 00 77 03 31 c0 c3 53 48
...
Call Trace:
<TASK>
? nilfs_palloc_freev.cold.24+0x58/0x58 [nilfs2]
nilfs_destroy_cachep+0x16/0x3a [nilfs2]
exit_nilfs_fs+0xa/0x1b [nilfs2]
__x64_sys_delete_module+0x1d9/0x3a0
? __sanitizer_cov_trace_pc+0x1a/0x50
? syscall_trace_enter.isra.19+0x119/0x190
do_syscall_64+0x34/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
...
</TASK>
Kernel panic - not syncing: panic_on_warn set ...
This patch fixes these issues by calling nilfs_detach_log_writer() cleanup
function if spawning the log writer thread fails.
Link: https://lkml.kernel.org/r/20221007085226.57667-1-konishi.ryusuke@gmail.com
Fixes: e912a5b668 ("nilfs2: use root object to get ifile")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+7381dc4ad60658ca4c05@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 21a87d88c2 upstream.
If the i_mode field in inode of metadata files is corrupted on disk, it
can cause the initialization of bmap structure, which should have been
called from nilfs_read_inode_common(), not to be called. This causes a
lockdep warning followed by a NULL pointer dereference at
nilfs_bmap_lookup_at_level().
This patch fixes these issues by adding a missing sanitiy check for the
i_mode field of metadata file's inode.
Link: https://lkml.kernel.org/r/20221002030804.29978-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+2b32eb36c1a825b7a74c@syzkaller.appspotmail.com
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5924e6ec15 upstream.
The permission flags of newly created symlinks are wrongly dropped on
nilfs2 with the current umask value even though symlinks should have 777
(rwxrwxrwx) permissions:
$ umask
0022
$ touch file && ln -s file symlink; ls -l file symlink
-rw-r--r--. 1 root root 0 Jun 23 16:29 file
lrwxr-xr-x. 1 root root 4 Jun 23 16:29 symlink -> file
This fixes the bug by inserting a missing check that excludes
symlinks.
Link: https://lkml.kernel.org/r/1655974441-5612-1-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: Tommy Pettersson <ptp@lysator.liu.se>
Reported-by: Ciprian Craciun <ciprian.craciun@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6e211930f7 ]
During disk space reclamation, nilfs2 still emits the following lockdep
warning due to page/folio operations on shadowed page caches that nilfs2
uses to get a snapshot of DAT file in memory:
WARNING: CPU: 0 PID: 2643 at include/linux/backing-dev.h:272 __folio_mark_dirty+0x645/0x670
...
RIP: 0010:__folio_mark_dirty+0x645/0x670
...
Call Trace:
filemap_dirty_folio+0x74/0xd0
__set_page_dirty_nobuffers+0x85/0xb0
nilfs_copy_dirty_pages+0x288/0x510 [nilfs2]
nilfs_mdt_save_to_shadow_map+0x50/0xe0 [nilfs2]
nilfs_clean_segments+0xee/0x5d0 [nilfs2]
nilfs_ioctl_clean_segments.isra.19+0xb08/0xf40 [nilfs2]
nilfs_ioctl+0xc52/0xfb0 [nilfs2]
__x64_sys_ioctl+0x11d/0x170
This fixes the remaining warning by using inode objects to hold those
page caches.
Link: https://lkml.kernel.org/r/1647867427-30498-3-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e897be17a4 ]
Patch series "nilfs2 lockdep warning fixes".
The first two are to resolve the lockdep warning issue, and the last one
is the accompanying cleanup and low priority.
Based on your comment, this series solves the issue by separating inode
object as needed. Since I was worried about the impact of the object
composition changes, I tested the series carefully not to cause
regressions especially for delicate functions such like disk space
reclamation and snapshots.
This patch (of 3):
If CONFIG_LOCKDEP is enabled, nilfs2 hits lockdep warnings at
inode_to_wb() during page/folio operations for btree nodes:
WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 inode_to_wb include/linux/backing-dev.h:269 [inline]
WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 folio_account_dirtied mm/page-writeback.c:2460 [inline]
WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 __folio_mark_dirty+0xa7c/0xe30 mm/page-writeback.c:2509
Modules linked in:
...
RIP: 0010:inode_to_wb include/linux/backing-dev.h:269 [inline]
RIP: 0010:folio_account_dirtied mm/page-writeback.c:2460 [inline]
RIP: 0010:__folio_mark_dirty+0xa7c/0xe30 mm/page-writeback.c:2509
...
Call Trace:
__set_page_dirty include/linux/pagemap.h:834 [inline]
mark_buffer_dirty+0x4e6/0x650 fs/buffer.c:1145
nilfs_btree_propagate_p fs/nilfs2/btree.c:1889 [inline]
nilfs_btree_propagate+0x4ae/0xea0 fs/nilfs2/btree.c:2085
nilfs_bmap_propagate+0x73/0x170 fs/nilfs2/bmap.c:337
nilfs_collect_dat_data+0x45/0xd0 fs/nilfs2/segment.c:625
nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1009
nilfs_segctor_scan_file+0x47a/0x700 fs/nilfs2/segment.c:1048
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1224 [inline]
nilfs_segctor_collect fs/nilfs2/segment.c:1494 [inline]
nilfs_segctor_do_construct+0x14f3/0x6c60 fs/nilfs2/segment.c:2036
nilfs_segctor_construct+0x7a7/0xb30 fs/nilfs2/segment.c:2372
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2480 [inline]
nilfs_segctor_thread+0x3c3/0xf90 fs/nilfs2/segment.c:2563
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
This is because nilfs2 uses two page caches for each inode and
inode->i_mapping never points to one of them, the btree node cache.
This causes inode_to_wb(inode) to refer to a different page cache than
the caller page/folio operations such like __folio_start_writeback(),
__folio_end_writeback(), or __folio_mark_dirty() acquired the lock.
This patch resolves the issue by allocating and using an additional
inode to hold the page cache of btree nodes. The inode is attached
one-to-one to the traditional nilfs2 inode if it requires a block
mapping with b-tree. This setup change is in memory only and does not
affect the disk format.
Link: https://lkml.kernel.org/r/1647867427-30498-1-git-send-email-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/1647867427-30498-2-git-send-email-konishi.ryusuke@gmail.com
Link: https://lore.kernel.org/r/YXrYvIo8YRnAOJCj@casper.infradead.org
Link: https://lore.kernel.org/r/9a20b33d-b38f-b4a2-4742-c1eb5b8e4d6c@redhat.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+0d5b462a6f07447991b3@syzkaller.appspotmail.com
Reported-by: syzbot+34ef28bb2aeb28724aa0@syzkaller.appspotmail.com
Reported-by: Hao Sun <sunhao.th@gmail.com>
Reported-by: David Hildenbrand <david@redhat.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b2fe39c248 ]
If kobject_init_and_add returns with error, kobject_put() is needed here
to avoid memory leak, because kobject_init_and_add may return error
without freeing the memory associated with the kobject it allocated.
Link: https://lkml.kernel.org/r/20210629022556.3985106-6-sunnanyong@huawei.com
Link: https://lkml.kernel.org/r/1625651306-10829-6-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 24f8cb1ed0 ]
If kobject_init_and_add return with error, kobject_put() is needed here to
avoid memory leak, because kobject_init_and_add may return error without
freeing the memory associated with the kobject it allocated.
Link: https://lkml.kernel.org/r/20210629022556.3985106-4-sunnanyong@huawei.com
Link: https://lkml.kernel.org/r/1625651306-10829-4-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dbc6e7d44a ]
In nilfs_##name##_attr_release, kobj->parent should not be referenced
because it is a NULL pointer. The release() method of kobject is always
called in kobject_put(kobj), in the implementation of kobject_put(), the
kobj->parent will be assigned as NULL before call the release() method.
So just use kobj to get the subgroups, which is more efficient and can fix
a NULL pointer reference problem.
Link: https://lkml.kernel.org/r/20210629022556.3985106-3-sunnanyong@huawei.com
Link: https://lkml.kernel.org/r/1625651306-10829-3-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5f5dec07ac ]
Patch series "nilfs2: fix incorrect usage of kobject".
This patchset from Nanyong Sun fixes memory leak issues and a NULL
pointer dereference issue caused by incorrect usage of kboject in nilfs2
sysfs implementation.
This patch (of 6):
Reported by syzkaller:
BUG: memory leak
unreferenced object 0xffff888100ca8988 (size 8):
comm "syz-executor.1", pid 1930, jiffies 4294745569 (age 18.052s)
hex dump (first 8 bytes):
6c 6f 6f 70 31 00 ff ff loop1...
backtrace:
kstrdup+0x36/0x70 mm/util.c:60
kstrdup_const+0x35/0x60 mm/util.c:83
kvasprintf_const+0xf1/0x180 lib/kasprintf.c:48
kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289
kobject_add_varg lib/kobject.c:384 [inline]
kobject_init_and_add+0xc9/0x150 lib/kobject.c:473
nilfs_sysfs_create_device_group+0x150/0x7d0 fs/nilfs2/sysfs.c:986
init_nilfs+0xa21/0xea0 fs/nilfs2/the_nilfs.c:637
nilfs_fill_super fs/nilfs2/super.c:1046 [inline]
nilfs_mount+0x7b4/0xe80 fs/nilfs2/super.c:1316
legacy_get_tree+0x105/0x210 fs/fs_context.c:592
vfs_get_tree+0x8e/0x2d0 fs/super.c:1498
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0xf9b/0x1990 fs/namespace.c:3235
do_mount+0xea/0x100 fs/namespace.c:3248
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount fs/namespace.c:3433 [inline]
__x64_sys_mount+0x14b/0x1f0 fs/namespace.c:3433
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
If kobject_init_and_add return with error, then the cleanup of kobject
is needed because memory may be allocated in kobject_init_and_add
without freeing.
And the place of cleanup_dev_kobject should use kobject_put to free the
memory associated with the kobject. As the section "Kobject removal" of
"Documentation/core-api/kobject.rst" says, kobject_del() just makes the
kobject "invisible", but it is not cleaned up. And no more cleanup will
do after cleanup_dev_kobject, so kobject_put is needed here.
Link: https://lkml.kernel.org/r/1625651306-10829-1-git-send-email-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/1625651306-10829-2-git-send-email-konishi.ryusuke@gmail.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Link: https://lkml.kernel.org/r/20210629022556.3985106-2-sunnanyong@huawei.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Ryusuke Konishi