[ Upstream commit be3e5d1064 ]
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: 7942b919f7 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
9472d37799