linux-stable.git/fs/nilfs2, branch linux-5.4.y

nilfs2: fix CFI failure when accessing /sys/fs/nilfs2/features/*

2025-10-02T11:34:31+00:00

commit 025e87f8ea2ae3a28bf1fe2b052bfa412c27ed4a upstream.

When accessing one of the files under /sys/fs/nilfs2/features when
CONFIG_CFI_CLANG is enabled, there is a CFI violation:

  CFI failure at kobj_attr_show+0x59/0x80 (target: nilfs_feature_revision_show+0x0/0x30; expected type: 0xfc392c4d)
  ...
  Call Trace:
   
   sysfs_kf_seq_show+0x2a6/0x390
   ? __cfi_kobj_attr_show+0x10/0x10
   kernfs_seq_show+0x104/0x15b
   seq_read_iter+0x580/0xe2b
  ...

When the kobject of the kset for /sys/fs/nilfs2 is initialized, its ktype
is set to kset_ktype, which has a ->sysfs_ops of kobj_sysfs_ops.  When
nilfs_feature_attr_group is added to that kobject via
sysfs_create_group(), the kernfs_ops of each files is sysfs_file_kfops_rw,
which will call sysfs_kf_seq_show() when ->seq_show() is called.
sysfs_kf_seq_show() in turn calls kobj_attr_show() through
->sysfs_ops->show().  kobj_attr_show() casts the provided attribute out to
a 'struct kobj_attribute' via container_of() and calls ->show(), resulting
in the CFI violation since neither nilfs_feature_revision_show() nor
nilfs_feature_README_show() match the prototype of ->show() in 'struct
kobj_attribute'.

Resolve the CFI violation by adjusting the second parameter in
nilfs_feature_{revision,README}_show() from 'struct attribute' to 'struct
kobj_attribute' to match the expected prototype.

Link: https://lkml.kernel.org/r/20250906144410.22511-1-konishi.ryusuke@gmail.com
Fixes: aebe17f68444 ("nilfs2: add /sys/fs/nilfs2/features group")
Signed-off-by: Nathan Chancellor 
Signed-off-by: Ryusuke Konishi 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-lkp/202509021646.bc78d9ef-lkp@intel.com/
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: reject invalid file types when reading inodes

2025-08-28T14:21:18+00:00

commit 4aead50caf67e01020c8be1945c3201e8a972a27 upstream.

To prevent inodes with invalid file types from tripping through the vfs
and causing malfunctions or assertion failures, add a missing sanity check
when reading an inode from a block device.  If the file type is not valid,
treat it as a filesystem error.

Link: https://lkml.kernel.org/r/20250710134952.29862-1-konishi.ryusuke@gmail.com
Fixes: 05fe58fdc10d ("nilfs2: inode operations")
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: do not propagate ENOENT error from nilfs_btree_propagate()

2025-06-27T10:02:47+00:00

[ Upstream commit 8e39fbb1edbb4ec9d7c1124f403877fc167fcecd ]

In preparation for writing logs, in nilfs_btree_propagate(), which makes
parent and ancestor node blocks dirty starting from a modified data block
or b-tree node block, if the starting block does not belong to the b-tree,
i.e.  is isolated, nilfs_btree_do_lookup() called within the function
fails with -ENOENT.

In this case, even though -ENOENT is an internal code, it is propagated to
the log writer via nilfs_bmap_propagate() and may be erroneously returned
to system calls such as fsync().

Fix this issue by changing the error code to -EINVAL in this case, and
having the bmap layer detect metadata corruption and convert the error
code appropriately.

Link: https://lkml.kernel.org/r/20250428173808.6452-3-konishi.ryusuke@gmail.com
Fixes: 1f5abe7e7dbc ("nilfs2: replace BUG_ON and BUG calls triggerable from ioctl")
Signed-off-by: Ryusuke Konishi 
Cc: Wentao Liang 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

nilfs2: add pointer check for nilfs_direct_propagate()

2025-06-27T10:02:47+00:00

[ Upstream commit f43f02429295486059605997bc43803527d69791 ]

Patch series "nilfs2: improve sanity checks in dirty state propagation".

This fixes one missed check for block mapping anomalies and one improper
return of an error code during a preparation step for log writing, thereby
improving checking for filesystem corruption on writeback.

This patch (of 2):

In nilfs_direct_propagate(), the printer get from nilfs_direct_get_ptr()
need to be checked to ensure it is not an invalid pointer.

If the pointer value obtained by nilfs_direct_get_ptr() is
NILFS_BMAP_INVALID_PTR, means that the metadata (in this case, i_bmap in
the nilfs_inode_info struct) that should point to the data block at the
buffer head of the argument is corrupted and the data block is orphaned,
meaning that the file system has lost consistency.

Add a value check and return -EINVAL when it is an invalid pointer.

Link: https://lkml.kernel.org/r/20250428173808.6452-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20250428173808.6452-2-konishi.ryusuke@gmail.com
Fixes: 36a580eb489f ("nilfs2: direct block mapping")
Signed-off-by: Wentao Liang 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

nilfs2: protect access to buffers with no active references

2025-03-13T11:43:18+00:00

commit 367a9bffabe08c04f6d725032cce3d891b2b9e1a upstream.

nilfs_lookup_dirty_data_buffers(), which iterates through the buffers
attached to dirty data folios/pages, accesses the attached buffers without
locking the folios/pages.

For data cache, nilfs_clear_folio_dirty() may be called asynchronously
when the file system degenerates to read only, so
nilfs_lookup_dirty_data_buffers() still has the potential to cause use
after free issues when buffers lose the protection of their dirty state
midway due to this asynchronous clearing and are unintentionally freed by
try_to_free_buffers().

Eliminate this race issue by adjusting the lock section in this function.

[konishi.ryusuke@gmail.com: adjusted for page/folio conversion]
Link: https://lkml.kernel.org/r/20250107200202.6432-3-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Fixes: 8c26c4e2694a ("nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption")
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: do not force clear folio if buffer is referenced

2025-03-13T11:43:18+00:00

commit ca76bb226bf47ff04c782cacbd299f12ddee1ec1 upstream.

Patch series "nilfs2: protect busy buffer heads from being force-cleared".

This series fixes the buffer head state inconsistency issues reported by
syzbot that occurs when the filesystem is corrupted and falls back to
read-only, and the associated buffer head use-after-free issue.

This patch (of 2):

Syzbot has reported that after nilfs2 detects filesystem corruption and
falls back to read-only, inconsistencies in the buffer state may occur.

One of the inconsistencies is that when nilfs2 calls mark_buffer_dirty()
to set a data or metadata buffer as dirty, but it detects that the buffer
is not in the uptodate state:

 WARNING: CPU: 0 PID: 6049 at fs/buffer.c:1177 mark_buffer_dirty+0x2e5/0x520
  fs/buffer.c:1177
 ...
 Call Trace:
  
  nilfs_palloc_commit_alloc_entry+0x4b/0x160 fs/nilfs2/alloc.c:598
  nilfs_ifile_create_inode+0x1dd/0x3a0 fs/nilfs2/ifile.c:73
  nilfs_new_inode+0x254/0x830 fs/nilfs2/inode.c:344
  nilfs_mkdir+0x10d/0x340 fs/nilfs2/namei.c:218
  vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257
  do_mkdirat+0x264/0x3a0 fs/namei.c:4280
  __do_sys_mkdirat fs/namei.c:4295 [inline]
  __se_sys_mkdirat fs/namei.c:4293 [inline]
  __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
  entry_SYSCALL_64_after_hwframe+0x77/0x7f

The other is when nilfs_btree_propagate(), which propagates the dirty
state to the ancestor nodes of a b-tree that point to a dirty buffer,
detects that the origin buffer is not dirty, even though it should be:

 WARNING: CPU: 0 PID: 5245 at fs/nilfs2/btree.c:2089
  nilfs_btree_propagate+0xc79/0xdf0 fs/nilfs2/btree.c:2089
 ...
 Call Trace:
  
  nilfs_bmap_propagate+0x75/0x120 fs/nilfs2/bmap.c:345
  nilfs_collect_file_data+0x4d/0xd0 fs/nilfs2/segment.c:587
  nilfs_segctor_apply_buffers+0x184/0x340 fs/nilfs2/segment.c:1006
  nilfs_segctor_scan_file+0x28c/0xa50 fs/nilfs2/segment.c:1045
  nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1216 [inline]
  nilfs_segctor_collect fs/nilfs2/segment.c:1540 [inline]
  nilfs_segctor_do_construct+0x1c28/0x6b90 fs/nilfs2/segment.c:2115
  nilfs_segctor_construct+0x181/0x6b0 fs/nilfs2/segment.c:2479
  nilfs_segctor_thread_construct fs/nilfs2/segment.c:2587 [inline]
  nilfs_segctor_thread+0x69e/0xe80 fs/nilfs2/segment.c:2701
  kthread+0x2f0/0x390 kernel/kthread.c:389
  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
  

Both of these issues are caused by the callbacks that handle the
page/folio write requests, forcibly clear various states, including the
working state of the buffers they hold, at unexpected times when they
detect read-only fallback.

Fix these issues by checking if the buffer is referenced before clearing
the page/folio state, and skipping the clear if it is.

[konishi.ryusuke@gmail.com: adjusted for page/folio conversion]
Link: https://lkml.kernel.org/r/20250107200202.6432-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20250107200202.6432-2-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+b2b14916b77acf8626d7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b2b14916b77acf8626d7
Reported-by: syzbot+d98fd19acd08b36ff422@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=d98fd19acd08b36ff422
Fixes: 8c26c4e2694a ("nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption")
Tested-by: syzbot+b2b14916b77acf8626d7@syzkaller.appspotmail.com
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: do not output warnings when clearing dirty buffers

2025-03-13T11:43:18+00:00

commit 299910dcb4525ac0274f3efa9527876315ba4f67 upstream.

After detecting file system corruption and degrading to a read-only mount,
dirty folios and buffers in the page cache are cleared, and a large number
of warnings are output at that time, often filling up the kernel log.

In this case, since the degrading to a read-only mount is output to the
kernel log, these warnings are not very meaningful, and are rather a
nuisance in system management and debugging.

The related nilfs2-specific page/folio routines have a silent argument
that suppresses the warning output, but since it is not currently used
meaningfully, remove both the silent argument and the warning output.

[konishi.ryusuke@gmail.com: adjusted for page/folio conversion]
Link: https://lkml.kernel.org/r/20240816090128.4561-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Stable-dep-of: ca76bb226bf4 ("nilfs2: do not force clear folio if buffer is referenced")
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix possible int overflows in nilfs_fiemap()

2025-03-13T11:43:11+00:00

commit 6438ef381c183444f7f9d1de18f22661cba1e946 upstream.

Since nilfs_bmap_lookup_contig() in nilfs_fiemap() calculates its result
by being prepared to go through potentially maxblocks == INT_MAX blocks,
the value in n may experience an overflow caused by left shift of blkbits.

While it is extremely unlikely to occur, play it safe and cast right hand
expression to wider type to mitigate the issue.

Found by Linux Verification Center (linuxtesting.org) with static analysis
tool SVACE.

Link: https://lkml.kernel.org/r/20250124222133.5323-1-konishi.ryusuke@gmail.com
Fixes: 622daaff0a89 ("nilfs2: fiemap support")
Signed-off-by: Nikita Zhandarovich 
Signed-off-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: handle errors that nilfs_prepare_chunk() may return

2025-03-13T11:43:04+00:00

commit ee70999a988b8abc3490609142f50ebaa8344432 upstream.

Patch series "nilfs2: fix issues with rename operations".

This series fixes BUG_ON check failures reported by syzbot around rename
operations, and a minor behavioral issue where the mtime of a child
directory changes when it is renamed instead of moved.


This patch (of 2):

The directory manipulation routines nilfs_set_link() and
nilfs_delete_entry() rewrite the directory entry in the folio/page
previously read by nilfs_find_entry(), so error handling is omitted on the
assumption that nilfs_prepare_chunk(), which prepares the buffer for
rewriting, will always succeed for these.  And if an error is returned, it
triggers the legacy BUG_ON() checks in each routine.

This assumption is wrong, as proven by syzbot: the buffer layer called by
nilfs_prepare_chunk() may call nilfs_get_block() if necessary, which may
fail due to metadata corruption or other reasons.  This has been there all
along, but improved sanity checks and error handling may have made it more
reproducible in fuzzing tests.

Fix this issue by adding missing error paths in nilfs_set_link(),
nilfs_delete_entry(), and their caller nilfs_rename().

Link: https://lkml.kernel.org/r/20250111143518.7901-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20250111143518.7901-2-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+32c3706ebf5d95046ea1@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=32c3706ebf5d95046ea1
Reported-by: syzbot+1097e95f134f37d9395c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1097e95f134f37d9395c
Fixes: 2ba466d74ed7 ("nilfs2: directory entry operations")
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: eliminate staggered calls to kunmap in nilfs_rename

2025-03-13T11:43:04+00:00

commit 8cf57c6df818f58fdad16a909506be213623a88e upstream.

In nilfs_rename(), calls to nilfs_put_page() to release pages obtained
with nilfs_find_entry() or nilfs_dotdot() are alternated in the normal
path.

When replacing the kernel memory mapping method from kmap to
kmap_local_{page,folio}, this violates the constraint on the calling order
of kunmap_local().

Swap the order of nilfs_put_page calls where the kmap sections of multiple
pages overlap so that they are nested, allowing direct replacement of
nilfs_put_page() -> unmap_and_put_page().

Without this reordering, that replacement will cause a kernel WARNING in
kunmap_local_indexed() on architectures with high memory mapping.

Link: https://lkml.kernel.org/r/20231127143036.2425-3-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Reviewed-by: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton 
Stable-dep-of: ee70999a988b ("nilfs2: handle errors that nilfs_prepare_chunk() may return")
Signed-off-by: Greg Kroah-Hartman