diff options
| author | Deepanshu Kartikey <kartikey406@gmail.com> | 2026-04-01 02:52:09 +0900 |
|---|---|---|
| committer | Viacheslav Dubeyko <slava@dubeyko.com> | 2026-03-31 11:05:55 -0700 |
| commit | be3e5d10643d3be1cbac9d9939f220a99253f980 (patch) | |
| tree | 770ef21685ebb10deaa51a0d923fd2ccc8fe6bb2 /fs/nilfs2 | |
| parent | 4a4e0328edd9e9755843787d28f16dd4165f8b48 (diff) | |
nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty()
nilfs_ioctl_mark_blocks_dirty() uses bd_oblocknr to detect dead blocks
by comparing it with the current block number bd_blocknr. If they differ,
the block is considered dead and skipped.
However, bd_oblocknr should never be 0 since block 0 typically stores the
primary superblock and is never a valid GC target block. A corrupted ioctl
request with bd_oblocknr set to 0 causes the comparison to incorrectly
match when the lookup returns -ENOENT and sets bd_blocknr to 0, bypassing
the dead block check and calling nilfs_bmap_mark() on a non-existent
block. This causes nilfs_btree_do_lookup() to return -ENOENT, triggering
the WARN_ON(ret == -ENOENT).
Fix this by rejecting ioctl requests with bd_oblocknr set to 0 at the
beginning of each iteration.
[ryusuke: slightly modified the commit message and comments for accuracy]
Fixes: 7942b919f732 ("nilfs2: ioctl operations")
Reported-by: syzbot+98a040252119df0506f8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=98a040252119df0506f8
Suggested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Deepanshu Kartikey <Kartikey406@gmail.com>
Reported-by: syzbot+466a45fcfb0562f5b9a0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=466a45fcfb0562f5b9a0
Cc: Junjie Cao <junjie.cao@linux.dev>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Diffstat (limited to 'fs/nilfs2')
| -rw-r--r-- | fs/nilfs2/ioctl.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c index e17b8da66491..e0a606643e87 100644 --- a/fs/nilfs2/ioctl.c +++ b/fs/nilfs2/ioctl.c @@ -736,6 +736,12 @@ static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs, int ret, i; for (i = 0; i < nmembs; i++) { + /* + * bd_oblocknr must never be 0 as block 0 + * is never a valid GC target block + */ + if (unlikely(!bdescs[i].bd_oblocknr)) + return -EINVAL; /* XXX: use macro or inline func to check liveness */ ret = nilfs_bmap_lookup_at_level(bmap, bdescs[i].bd_offset, |