linux.git/fs/jffs2, branch v6.16

jffs2: check jffs2_prealloc_raw_node_refs() result in few other places

2025-05-22T18:54:38+00:00

Fuzzing hit another invalid pointer dereference due to the lack of
checking whether jffs2_prealloc_raw_node_refs() completed successfully.
Subsequent logic implies that the node refs have been allocated.

Handle that. The code is ready for propagating the error upwards.

KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 5835 Comm: syz-executor145 Not tainted 5.10.234-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:jffs2_link_node_ref+0xac/0x690 fs/jffs2/nodelist.c:600
Call Trace:
 jffs2_mark_erased_block fs/jffs2/erase.c:460 [inline]
 jffs2_erase_pending_blocks+0x688/0x1860 fs/jffs2/erase.c:118
 jffs2_garbage_collect_pass+0x638/0x1a00 fs/jffs2/gc.c:253
 jffs2_reserve_space+0x3f4/0xad0 fs/jffs2/nodemgmt.c:167
 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362
 jffs2_write_end+0x712/0x1110 fs/jffs2/file.c:302
 generic_perform_write+0x2c2/0x500 mm/filemap.c:3347
 __generic_file_write_iter+0x252/0x610 mm/filemap.c:3465
 generic_file_write_iter+0xdb/0x230 mm/filemap.c:3497
 call_write_iter include/linux/fs.h:2039 [inline]
 do_iter_readv_writev+0x46d/0x750 fs/read_write.c:740
 do_iter_write+0x18c/0x710 fs/read_write.c:866
 vfs_writev+0x1db/0x6a0 fs/read_write.c:939
 do_pwritev fs/read_write.c:1036 [inline]
 __do_sys_pwritev fs/read_write.c:1083 [inline]
 __se_sys_pwritev fs/read_write.c:1078 [inline]
 __x64_sys_pwritev+0x235/0x310 fs/read_write.c:1078
 do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x67/0xd1

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 2f785402f39b ("[JFFS2] Reduce visibility of raw_node_ref to upper layers of JFFS2 code.")
Fixes: f560928baa60 ("[JFFS2] Allocate node_ref for wasted space when skipping to page boundary")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin 
Reviewed-by: Zhihao Cheng 
Signed-off-by: Richard Weinberger

jffs2: check that raw node were preallocated before writing summary

2025-05-22T18:53:32+00:00

Syzkaller detected a kernel bug in jffs2_link_node_ref, caused by fault
injection in jffs2_prealloc_raw_node_refs. jffs2_sum_write_sumnode doesn't
check return value of jffs2_prealloc_raw_node_refs and simply lets any
error propagate into jffs2_sum_write_data, which eventually calls
jffs2_link_node_ref in order to link the summary to an expectedly allocated
node.

kernel BUG at fs/jffs2/nodelist.c:592!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 PID: 31277 Comm: syz-executor.7 Not tainted 6.1.128-syzkaller-00139-ge10f83ca10a1 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:jffs2_link_node_ref+0x570/0x690 fs/jffs2/nodelist.c:592
Call Trace:
 
 jffs2_sum_write_data fs/jffs2/summary.c:841 [inline]
 jffs2_sum_write_sumnode+0xd1a/0x1da0 fs/jffs2/summary.c:874
 jffs2_do_reserve_space+0xa18/0xd60 fs/jffs2/nodemgmt.c:388
 jffs2_reserve_space+0x55f/0xaa0 fs/jffs2/nodemgmt.c:197
 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362
 jffs2_write_end+0x726/0x15d0 fs/jffs2/file.c:301
 generic_perform_write+0x314/0x5d0 mm/filemap.c:3856
 __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3973
 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4005
 call_write_iter include/linux/fs.h:2265 [inline]
 do_iter_readv_writev+0x20f/0x3c0 fs/read_write.c:735
 do_iter_write+0x186/0x710 fs/read_write.c:861
 vfs_iter_write+0x70/0xa0 fs/read_write.c:902
 iter_file_splice_write+0x73b/0xc90 fs/splice.c:685
 do_splice_from fs/splice.c:763 [inline]
 direct_splice_actor+0x10c/0x170 fs/splice.c:950
 splice_direct_to_actor+0x337/0xa10 fs/splice.c:896
 do_splice_direct+0x1a9/0x280 fs/splice.c:1002
 do_sendfile+0xb13/0x12c0 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Fix this issue by checking return value of jffs2_prealloc_raw_node_refs
before calling jffs2_sum_write_data.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Cc: stable@vger.kernel.org
Fixes: 2f785402f39b ("[JFFS2] Reduce visibility of raw_node_ref to upper layers of JFFS2 code.")
Signed-off-by: Artem Sadovnikov 
Reviewed-by: Zhihao Cheng 
Signed-off-by: Richard Weinberger

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

Change inode_operations.mkdir to return struct dentry *

2025-02-27T19:00:17+00:00

Some filesystems, such as NFS, cifs, ceph, and fuse, do not have
complete control of sequencing on the actual filesystem (e.g.  on a
different server) and may find that the inode created for a mkdir
request already exists in the icache and dcache by the time the mkdir
request returns.  For example, if the filesystem is mounted twice the
directory could be visible on the other mount before it is on the
original mount, and a pair of name_to_handle_at(), open_by_handle_at()
calls could instantiate the directory inode with an IS_ROOT() dentry
before the first mkdir returns.

This means that the dentry passed to ->mkdir() may not be the one that
is associated with the inode after the ->mkdir() completes.  Some
callers need to interact with the inode after the ->mkdir completes and
they currently need to perform a lookup in the (rare) case that the
dentry is no longer hashed.

This lookup-after-mkdir requires that the directory remains locked to
avoid races.  Planned future patches to lock the dentry rather than the
directory will mean that this lookup cannot be performed atomically with
the mkdir.

To remove this barrier, this patch changes ->mkdir to return the
resulting dentry if it is different from the one passed in.
Possible returns are:
  NULL - the directory was created and no other dentry was used
  ERR_PTR() - an error occurred
  non-NULL - this other dentry was spliced in

This patch only changes file-systems to return "ERR_PTR(err)" instead of
"err" or equivalent transformations.  Subsequent patches will make
further changes to some file-systems to return a correct dentry.

Not all filesystems reliably result in a positive hashed dentry:

- NFS, cifs, hostfs will sometimes need to perform a lookup of
  the name to get inode information.  Races could result in this
  returning something different. Note that this lookup is
  non-atomic which is what we are trying to avoid.  Placing the
  lookup in filesystem code means it only happens when the filesystem
  has no other option.
- kernfs and tracefs leave the dentry negative and the ->revalidate
  operation ensures that lookup will be called to correctly populate
  the dentry.  This could be fixed but I don't think it is important
  to any of the users of vfs_mkdir() which look at the dentry.

The recommendation to use
    d_drop();d_splice_alias()
is ugly but fits with current practice.  A planned future patch will
change this.

Reviewed-by: Jeff Layton 
Reviewed-by: Jan Kara 
Signed-off-by: NeilBrown 
Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de
Signed-off-by: Christian Brauner

jffs2: Fix rtime decompressor

2024-12-05T11:31:40+00:00

The fix for a memory corruption contained a off-by-one error and
caused the compressor to fail in legit cases.

Cc: Kinsey Moore 
Cc: stable@vger.kernel.org
Fixes: fe051552f5078 ("jffs2: Prevent rtime decompress memory corruption")
Signed-off-by: Richard Weinberger

jffs2: Prevent rtime decompress memory corruption

2024-11-14T19:56:19+00:00

The rtime decompression routine does not fully check bounds during the
entirety of the decompression pass and can corrupt memory outside the
decompression buffer if the compressed data is corrupted. This adds the
required check to prevent this failure mode.

Cc: stable@vger.kernel.org
Signed-off-by: Kinsey Moore 
Signed-off-by: Richard Weinberger

jffs2: remove redundant check on outpos > pos

2024-11-14T19:27:39+00:00

The check for outpos > pos is always false because outpos is zero
and pos is at least zero; outpos can never be greater than pos.
The check is redundant and can be removed.

Signed-off-by: Colin Ian King 
Signed-off-by: Richard Weinberger

fs: jffs2: Fix inconsistent indentation in jffs2_mark_node_obsolete

2024-11-14T19:21:53+00:00

Fix the indentation to ensure consistent code style and improve
readability, and to fix this warnings:
fs/jffs2/nodemgmt.c:635 jffs2_mark_node_obsolete() warn: inconsistent
indenting
fs/jffs2/nodemgmt.c:646 jffs2_mark_node_obsolete() warn: inconsistent
indenting

Signed-off-by: Suraj Sonawane 
Reviewed-by: Zhihao Cheng 
Signed-off-by: Richard Weinberger

jffs2: Correct some typos in comments

2024-11-14T19:15:55+00:00

Fixed some confusing spelling errors, the details are as follows:

-in the code comments:
	wating		-> waiting
	succefully	-> successfully

Signed-off-by: Shen Lichuan 
Reviewed-by: Zhihao Cheng 
Signed-off-by: Richard Weinberger

jffs2: fix use of uninitialized variable

2024-11-14T19:14:27+00:00

When building the kernel with -Wmaybe-uninitialized, the compiler
reports this warning:

In function 'jffs2_mark_erased_block',
    inlined from 'jffs2_erase_pending_blocks' at fs/jffs2/erase.c:116:4:
fs/jffs2/erase.c:474:9: warning: 'bad_offset' may be used uninitialized [-Wmaybe-uninitialized]
  474 |         jffs2_erase_failed(c, jeb, bad_offset);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/jffs2/erase.c: In function 'jffs2_erase_pending_blocks':
fs/jffs2/erase.c:402:18: note: 'bad_offset' was declared here
  402 |         uint32_t bad_offset;
      |                  ^~~~~~~~~~

When mtd->point() is used, jffs2_erase_pending_blocks can return -EIO
without initializing bad_offset, which is later used at the filebad
label in jffs2_mark_erased_block.
Fix it by initializing this variable.

Fixes: 8a0f572397ca ("[JFFS2] Return values of jffs2_block_check_erase error paths")
Signed-off-by: Qingfang Deng 
Reviewed-by: Zhihao Cheng 
Signed-off-by: Richard Weinberger