linux.git/fs/nilfs2, branch vsnprintf

nilfs2: fix buffer head leaks in calls to truncate_inode_pages()

2024-12-19T03:04:45+00:00

When block_invalidatepage was converted to block_invalidate_folio, the
fallback to block_invalidatepage in folio_invalidate() if the
address_space_operations method invalidatepage (currently
invalidate_folio) was not set, was removed.

Unfortunately, some pseudo-inodes in nilfs2 use empty_aops set by
inode_init_always_gfp() as is, or explicitly set it to
address_space_operations.  Therefore, with this change,
block_invalidatepage() is no longer called from folio_invalidate(), and as
a result, the buffer_head structures attached to these pages/folios are no
longer freed via try_to_free_buffers().

Thus, these buffer heads are now leaked by truncate_inode_pages(), which
cleans up the page cache from inode evict(), etc.

Three types of caches use empty_aops: gc inode caches and the DAT shadow
inode used by GC, and b-tree node caches.  Of these, b-tree node caches
explicitly call invalidate_mapping_pages() during cleanup, which involves
calling try_to_free_buffers(), so the leak was not visible during normal
operation but worsened when GC was performed.

Fix this issue by using address_space_operations with invalidate_folio set
to block_invalidate_folio instead of empty_aops, which will ensure the
same behavior as before.

Link: https://lkml.kernel.org/r/20241212164556.21338-1-konishi.ryusuke@gmail.com
Fixes: 7ba13abbd31e ("fs: Turn block_invalidatepage into block_invalidate_folio")
Signed-off-by: Ryusuke Konishi 
Cc: 	[5.18+]
Signed-off-by: Andrew Morton

nilfs2: prevent use of deleted inode

2024-12-19T03:04:44+00:00

syzbot reported a WARNING in nilfs_rmdir. [1]

Because the inode bitmap is corrupted, an inode with an inode number that
should exist as a ".nilfs" file was reassigned by nilfs_mkdir for "file0",
causing an inode duplication during execution.  And this causes an
underflow of i_nlink in rmdir operations.

The inode is used twice by the same task to unmount and remove directories
".nilfs" and "file0", it trigger warning in nilfs_rmdir.

Avoid to this issue, check i_nlink in nilfs_iget(), if it is 0, it means
that this inode has been deleted, and iput is executed to reclaim it.

[1]
WARNING: CPU: 1 PID: 5824 at fs/inode.c:407 drop_nlink+0xc4/0x110 fs/inode.c:407
...
Call Trace:
 
 nilfs_rmdir+0x1b0/0x250 fs/nilfs2/namei.c:342
 vfs_rmdir+0x3a3/0x510 fs/namei.c:4394
 do_rmdir+0x3b5/0x580 fs/namei.c:4453
 __do_sys_rmdir fs/namei.c:4472 [inline]
 __se_sys_rmdir fs/namei.c:4470 [inline]
 __x64_sys_rmdir+0x47/0x50 fs/namei.c:4470
 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

Link: https://lkml.kernel.org/r/20241209065759.6781-1-konishi.ryusuke@gmail.com
Fixes: d25006523d0b ("nilfs2: pathname operations")
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+9260555647a5132edd48@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9260555647a5132edd48
Tested-by: syzbot+9260555647a5132edd48@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis 
Cc: 
Signed-off-by: Andrew Morton

nilfs2: fix potential out-of-bounds memory access in nilfs_find_entry()

2024-12-06T03:54:43+00:00

Syzbot reported that when searching for records in a directory where the
inode's i_size is corrupted and has a large value, memory access outside
the folio/page range may occur, or a use-after-free bug may be detected if
KASAN is enabled.

This is because nilfs_last_byte(), which is called by nilfs_find_entry()
and others to calculate the number of valid bytes of directory data in a
page from i_size and the page index, loses the upper 32 bits of the 64-bit
size information due to an inappropriate type of local variable to which
the i_size value is assigned.

This caused a large byte offset value due to underflow in the end address
calculation in the calling nilfs_find_entry(), resulting in memory access
that exceeds the folio/page size.

Fix this issue by changing the type of the local variable causing the bit
loss from "unsigned int" to "u64".  The return value of nilfs_last_byte()
is also of type "unsigned int", but it is truncated so as not to exceed
PAGE_SIZE and no bit loss occurs, so no change is required.

Link: https://lkml.kernel.org/r/20241119172403.9292-1-konishi.ryusuke@gmail.com
Fixes: 2ba466d74ed7 ("nilfs2: directory entry operations")
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+96d5d14c47d97015c624@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=96d5d14c47d97015c624
Tested-by: syzbot+96d5d14c47d97015c624@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-11-26T00:09:48+00:00

Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...

Merge tag 'vfs-6.13.pagecache' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-11-18T17:54:32+00:00

Pull vfs pagecache updates from Christian Brauner:
 "Cleanup filesystem page flag usage: This continues the work to make
  the mappedtodisk/owner_2 flag available to filesystems which don't use
  buffer heads. Further patches remove uses of Private2. This brings us
  very close to being rid of it entirely"

* tag 'vfs-6.13.pagecache' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  migrate: Remove references to Private2
  ceph: Remove call to PagePrivate2()
  btrfs: Switch from using the private_2 flag to owner_2
  mm: Remove PageMappedToDisk
  nilfs2: Convert nilfs_copy_buffer() to use folios
  fs: Move clearing of mappedtodisk to buffer.c

nilfs2: fix null-ptr-deref in block_dirty_buffer tracepoint

2024-11-12T01:20:23+00:00

When using the "block:block_dirty_buffer" tracepoint, mark_buffer_dirty()
may cause a NULL pointer dereference, or a general protection fault when
KASAN is enabled.

This happens because, since the tracepoint was added in
mark_buffer_dirty(), it references the dev_t member bh->b_bdev->bd_dev
regardless of whether the buffer head has a pointer to a block_device
structure.

In the current implementation, nilfs_grab_buffer(), which grabs a buffer
to read (or create) a block of metadata, including b-tree node blocks,
does not set the block device, but instead does so only if the buffer is
not in the "uptodate" state for each of its caller block reading
functions.  However, if the uptodate flag is set on a folio/page, and the
buffer heads are detached from it by try_to_free_buffers(), and new buffer
heads are then attached by create_empty_buffers(), the uptodate flag may
be restored to each buffer without the block device being set to
bh->b_bdev, and mark_buffer_dirty() may be called later in that state,
resulting in the bug mentioned above.

Fix this issue by making nilfs_grab_buffer() always set the block device
of the super block structure to the buffer head, regardless of the state
of the buffer's uptodate flag.

Link: https://lkml.kernel.org/r/20241106160811.3316-3-konishi.ryusuke@gmail.com
Fixes: 5305cb830834 ("block: add block_{touch|dirty}_buffer tracepoint")
Signed-off-by: Ryusuke Konishi 
Cc: Tejun Heo 
Cc: Ubisectech Sirius 
Cc: 
Signed-off-by: Andrew Morton

nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint

2024-11-12T01:20:23+00:00

Patch series "nilfs2: fix null-ptr-deref bugs on block tracepoints".

This series fixes null pointer dereference bugs that occur when using
nilfs2 and two block-related tracepoints.


This patch (of 2):

It has been reported that when using "block:block_touch_buffer"
tracepoint, touch_buffer() called from __nilfs_get_folio_block() causes a
NULL pointer dereference, or a general protection fault when KASAN is
enabled.

This happens because since the tracepoint was added in touch_buffer(), it
references the dev_t member bh->b_bdev->bd_dev regardless of whether the
buffer head has a pointer to a block_device structure.  In the current
implementation, the block_device structure is set after the function
returns to the caller.

Here, touch_buffer() is used to mark the folio/page that owns the buffer
head as accessed, but the common search helper for folio/page used by the
caller function was optimized to mark the folio/page as accessed when it
was reimplemented a long time ago, eliminating the need to call
touch_buffer() here in the first place.

So this solves the issue by eliminating the touch_buffer() call itself.

Link: https://lkml.kernel.org/r/20241106160811.3316-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20241106160811.3316-2-konishi.ryusuke@gmail.com
Fixes: 5305cb830834 ("block: add block_{touch|dirty}_buffer tracepoint")
Signed-off-by: Ryusuke Konishi 
Reported-by: Ubisectech Sirius 
Closes: https://lkml.kernel.org/r/86bd3013-887e-4e38-960f-ca45c657f032.bugreport@valiantsec.com
Reported-by: syzbot+9982fb8d18eba905abe2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9982fb8d18eba905abe2
Tested-by: syzbot+9982fb8d18eba905abe2@syzkaller.appspotmail.com
Cc: Tejun Heo 
Cc: 
Signed-off-by: Andrew Morton

nilfs2: convert metadata aops from writepage to writepages

2024-11-06T01:12:40+00:00

By implementing ->writepages instead of ->writepage, we remove a layer of
indirect function calls from the writeback path and the last use of struct
page in nilfs2.

[konishi.ryusuke@gmail.com: fixed panic by using buffer_migrate_folio_norefs]
Link: https://lkml.kernel.org/r/20241002150036.1339475-5-willy@infradead.org
Link: https://lkml.kernel.org/r/20241024092602.13395-13-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton

nilfs2: convert nilfs_recovery_copy_block() to take a folio

2024-11-06T01:12:40+00:00

Use memcpy_to_folio() instead of open-coding it, and use offset_in_folio()
in case anybody wants to use nilfs2 on a device with large blocks.

[konishi.ryusuke@gmail.com: added label name change]
Link: https://lkml.kernel.org/r/20241002150036.1339475-4-willy@infradead.org
Link: https://lkml.kernel.org/r/20241024092602.13395-12-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton

nilfs2: convert nilfs_page_count_clean_buffers() to take a folio

2024-11-06T01:12:39+00:00

Both callers have a folio, so pass it in and use it directly.

[konishi.ryusuke@gmail.com: fixed a checkpatch warning about function declaration]
Link: https://lkml.kernel.org/r/20241002150036.1339475-3-willy@infradead.org
Link: https://lkml.kernel.org/r/20241024092602.13395-11-konishi.ryusuke@gmail.com
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton