Re: [PATCH] bcachefs: return err ptr instead of null in read sb clean

[Kent Overstreet]

On Tue, Sep 10, 2024 at 06:18:34PM GMT, Diogo Jahchan Koike wrote:
> syzbot reported a null-ptr-deref in bch2_fs_start. [0]
> 
> When a sb is marked clear but doesn't have a clean section
> bch2_read_superblock_clean returns NULL which PTR_ERR_OR_ZERO
> lets through, eventually leading to a null ptr dereference down
> the line. Adjust read sb clean to return an ERR_PTR indicating the
> invalid clean section.
> 
> [0] https://syzkaller.appspot.com/bug?extid=1cecc37d87c4286e5543
> 
> Reported-by: syzbot+1cecc37d87c4286e5543@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes: https://syzkaller.appspot.com/bug?extid=1cecc37d87c4286e5543
> Signed-off-by: Diogo Jahchan Koike <djahchankoike@xxxxxxxxx>

Thanks, applied