[PATCH 2/2] erofs: validate the extent length for uncompressed pclusters

[Chao Yu]

On 2022/12/5 23:00, Gao Xiang wrote:
> syzkaller reported a KASAN use-after-free:
> https://syzkaller.appspot.com/bug?extid=2ae90e873e97f1faf6f2
> 
> The referenced fuzzed image actually has two issues:
>   - m_pa == 0 as a non-inlined pcluster;
>   - The logical length is longer than its physical length.
> 
> The first issue has already been addressed.  This patch addresses
> the second issue by checking the extent length validity.
> 
> Reported-by: syzbot+2ae90e873e97f1faf6f2 at syzkaller.appspotmail.com
> Fixes: 02827e1796b3 ("staging: erofs: add erofs_map_blocks_iter")
> Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>

Reviewed-by: Chao Yu <chao at kernel.org>

Thanks,