Re: [PATCH] f2fs: use the mount idmap for the owner check in f2fs_xattr_advise_set()

[Chao Yu <chao@kernel.org>]

On 7/16/26 10:59, Zhan Xusheng wrote:
> f2fs_xattr_advise_set() calls inode_owner_or_capable() with &nop_mnt_idmap
> before allowing the "system.advise" xattr to be set, instead of the idmap
> that the VFS passes to the ->set() handler.
> 
> f2fs supports idmapped mounts, so on such a mount this checks the caller's
> fsuid against the unmapped on-disk owner rather than the mapped owner: the
> actual owner can be wrongly denied with -EPERM and an unrelated caller
> wrongly allowed.  Pass the handler's idmap instead.
> 
> Fixes: 01beba7957a2 ("fs: port inode_owner_or_capable() to mnt_idmap")
> Cc: stable@vger.kernel.org
> Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>

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

Thanks,