Re: [PATCH v2] hfsplus: Remove the duplicate attr inode dirty marking action

[Viacheslav Dubeyko]

On Thu, 2026-04-16 at 11:37 +0800, Edward Adam Davis wrote:
> Syzbot reported a null-ptr-deref in [1].
> If the attributes file is not loaded during system mount, a trigger
> occurs [1] when setxattr is executed in userspace.
> 
> Remove the first mark attr inode dirty operation.
> 
> [1]
> KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> Call Trace:
>  hfsplus_setxattr+0x124/0x340 fs/hfsplus/xattr.c:555
>  hfsplus_trusted_setxattr+0x40/0x60 fs/hfsplus/xattr_trusted.c:30
>  __vfs_setxattr+0x43c/0x480 fs/xattr.c:218
>  __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:252
>  vfs_setxattr+0x163/0x360 fs/xattr.c:339
>  do_setxattr fs/xattr.c:654 [inline]
> 
> Reported-by: syzbot+bc70a12e438dadba4fb4@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: ee8422d00b7c ("hfsplus: fix potential Allocation File corruption after fsync")
> Closes: https://syzkaller.appspot.com/bug?extid=bc70a12e438dadba4fb4
> Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
> ---
> v1 -> v2: just remove first mark dirty
> 
>  fs/hfsplus/xattr.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
> index 452a1f9becb2..21a1c196c71f 100644
> --- a/fs/hfsplus/xattr.c
> +++ b/fs/hfsplus/xattr.c
> @@ -317,7 +317,6 @@ static int hfsplus_create_attributes_file(struct super_block *sb)
>  		next_node++;
>  	}
>  
> -	hfsplus_mark_inode_dirty(HFSPLUS_ATTR_TREE_I(sb), HFSPLUS_I_ATTR_DIRTY);
>  	hfsplus_mark_inode_dirty(attr_file, HFSPLUS_I_ATTR_DIRTY);
>  
>  	sbi->attr_tree = hfs_btree_open(sb, HFSPLUS_ATTR_CNID);

Looks good.

Reviewed-by: Viacheslav Dubeyko <slava@xxxxxxxxxxx>

Thanks,
Slava.