Commit graph

3 commits

Author SHA1 Message Date
Gao Xiang
08a4c231f1 erofs: fix incorrect symlink detection in fast symlink
commit 9ed50b8231e37b1ae863f5dec8153b98d9f389b4 upstream.

Fast symlink can be used if the on-disk symlink data is stored
in the same block as the on-disk inode, so we don’t need to trigger
another I/O for symlink data.  However, currently fs correction could be
reported _incorrectly_ if inode xattrs are too large.

In fact, these should be valid images although they cannot be handled as
fast symlinks.

Many thanks to Colin for reporting this!

Reported-by: Colin Walters <walters@verbum.org>
Reported-by: https://honggfuzz.dev/
Link: https://lore.kernel.org/r/bb2dd430-7de0-47da-ae5b-82ab2dd4d945@app.fastmail.com
Fixes: 431339ba9042 ("staging: erofs: add inode operations")
[ Note that it's a runtime misbehavior instead of a security issue. ]
Link: https://lore.kernel.org/r/20240909031911.1174718-1-hsiangkao@linux.alibaba.com
[ Gao Xiang: fix 5.10.y build warning due to `check_add_overflow`. ]
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-15 16:29:40 +01:00
Gao Xiang
9fc2be9da8 erofs: fix order >= MAX_ORDER warning due to crafted negative i_size
commit 1dd73601a1cba37a0ed5f89a8662c90191df5873 upstream.

As syzbot reported [1], the root cause is that i_size field is a
signed type, and negative i_size is also less than EROFS_BLKSIZ.
As a consequence, it's handled as fast symlink unexpectedly.

Let's fall back to the generic path to deal with such unusual i_size.

[1] https://lore.kernel.org/r/000000000000ac8efa05e7feaa1f@google.com

Reported-by: syzbot+f966c13b1b4fc0403b19@syzkaller.appspotmail.com
Fixes: 431339ba9042 ("staging: erofs: add inode operations")
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Link: https://lore.kernel.org/r/20220909023948.28925-1-hsiangkao@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-15 16:29:40 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00