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

[Christian Brauner]

Hi Rochan,

> f2fs_xattr_advise_set() calls inode_owner_or_capable() with
> &nop_mnt_idmap before allowing the advise xattr to be set, instead of
> the idmap that was passed into the handler.
> 
> Since f2fs supports idmapped mounts, this compares the caller's fsuid
> against the unmapped on-disk owner rather than the mapped owner; resulting
> in the actual owner to be wrongly denied with -EPERM. Use the idmap
> argument that was already passed to the xattr handler instead.
> 
> Fixes: 984fc4e76d63 ("f2fs: support idmapped mounts")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Rochan Avlur <rochan.avlur@xxxxxxxxx>

Seems generally fine to me,
Acked-by: Christian Brauner (Amutable) <braurg>

--