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

[Rochan Avlur <rochan.avlur@gmail.com>]

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@vger.kernel.org
Signed-off-by: Rochan Avlur <rochan.avlur@gmail.com>
---
 fs/f2fs/xattr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 610d5810074d..281e2fd6c778 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -118,7 +118,7 @@ static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
 	unsigned char old_advise = F2FS_I(inode)->i_advise;
 	unsigned char new_advise;
 
-	if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
+	if (!inode_owner_or_capable(idmap, inode))
 		return -EPERM;
 	if (value == NULL)
 		return -EINVAL;
-- 
2.45.2