Re: [PATCH v2] erofs: fix null-ptr-deref caused by erofs_xattr_prefixes_init

[Chao Yu]

On 2023/5/15 18:39, Jingbo Xu wrote:
> Fragments and dedupe share one feature bit, and thus packed inode may not
> exist when fragment feature bit (dedupe feature bit exactly) is set, e.g.
> when deduplication feature is in use while fragments feature is not.  In
> this case, sbi->packed_inode could be NULL while fragments feature bit
> is set.
>
> Fix this by accessing packed inode only when it exists.
>
> Reported-by: syzbot+902d5a9373ae8f748a94@xxxxxxxxxxxxxxxxxxxxxxxxx
> Link: https://syzkaller.appspot.com/bug?extid=902d5a9373ae8f748a94
> Fixes: 9e382914617c ("erofs: add helpers to load long xattr name prefixes")
> Signed-off-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,