Assumption never checked, should fail if the mounter creds are not
sufficient.
Signed-off-by: Mark Salyzyn <saly...@android.com>
Cc: Miklos Szeredi <mik...@szeredi.hu>
Cc: Jonathan Corbet <cor...@lwn.net>
Cc: Vivek Goyal <vgo...@redhat.com>
Cc: Eric W. Biederman <ebied...@xmission.com>
Cc: Amir Goldstein <amir7...@gmail.com>
Cc: Randy Dunlap <rdun...@infradead.org>
Cc: Stephen Smalley <s...@tycho.nsa.gov>
Cc: linux-unio...@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-ker...@vger.kernel.org
Cc: kernel-t...@android.com
v5:
- dependency of "overlayfs: override_creds=off option bypass creator_cred"
v6:
- rebase
---
fs/overlayfs/namei.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index efd372312ef1..aa012b6bd46e 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -163,6 +163,11 @@ struct dentry *ovl_decode_real_fh(struct ovl_fh *fh,
struct vfsmount *mnt,
if (!uuid_equal(&fh->uuid, &mnt->mnt_sb->s_uuid))
return NULL;
+ if (!capable(CAP_DAC_READ_SEARCH)) {
+ origin = ERR_PTR(-EPERM);
+ goto out;
+ }
+
bytes = (fh->len - offsetof(struct ovl_fh, fid));
real = exportfs_decode_fh(mnt, (struct fid *)fh->fid,
bytes >> 2, (int)fh->type,
--
2.19.1.930.g4563a0d9d0-goog
