ceph: just skip unrecognized info in ceph_reply_info_extra

In the future, we're going to want to extend the ceph_reply_info_extra
for create replies. Currently though, the kernel code doesn't accept an
extra blob that is larger than the expected data.

Change the code to skip over any unrecognized fields at the end of the
extra blob, rather than returning -EIO.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index a8a8f84f3bbfae462ba8001faa0dac7721ce883f..a5163296d9d9b10518a1942ee95c2a96f2301cf6 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -384,8 +384,8 @@ static int parse_reply_info_readdir(void **p, void *end,
        }
 
 done:
-       if (*p != end)
-               goto bad;
+       /* Skip over any unrecognized fields */
+       *p = end;
        return 0;
 
 bad:
@@ -406,12 +406,10 @@ static int parse_reply_info_filelock(void **p, void *end,
                goto bad;
 
        info->filelock_reply = *p;
-       *p += sizeof(*info->filelock_reply);
 
-       if (unlikely(*p != end))
-               goto bad;
+       /* Skip over any unrecognized fields */
+       *p = end;
        return 0;
-
 bad:
        return -EIO;
 }
@@ -425,18 +423,21 @@ static int parse_reply_info_create(void **p, void *end,
 {
        if (features == (u64)-1 ||
            (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
+               /* Malformed reply? */
                if (*p == end) {
                        info->has_create_ino = false;
                } else {
                        info->has_create_ino = true;
-                       info->ino = ceph_decode_64(p);
+                       ceph_decode_64_safe(p, end, info->ino, bad);
                }
+       } else {
+               if (*p != end)
+                       goto bad;
        }
 
-       if (unlikely(*p != end))
-               goto bad;
+       /* Skip over any unrecognized fields */
+       *p = end;
        return 0;
-
 bad:
        return -EIO;
 }