1 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/ceph/decode.h b/include/linux/ceph/decode.h
index 220ae21e819b..d8615dee5808 100644
--- a/include/linux/ceph/decode.h
+++ b/include/linux/ceph/decode.h
@@ -46,9 +46,14 @@ static inline void ceph_decode_copy(void **p, void *pv, size_t n)
 /*
  * bounds check input.
  */
+static inline int ceph_has_room(void **p, void *end, size_t n)
+{
+        return end >= *p && n <= end - *p;
+}
+
 #define ceph_decode_need(p, end, n, bad)                \
         do {                                            \
-                if (unlikely(*(p) + (n) > (end)))       \
+                if (!likely(ceph_has_room(p, end, n)))  \
                         goto bad;                       \
         } while (0)
 
@@ -167,7 +172,7 @@ static inline void ceph_encode_string(void **p, void *end,
 
 #define ceph_encode_need(p, end, n, bad)                \
         do {                                            \
-                if (unlikely(*(p) + (n) > (end)))       \
+                if (!likely(ceph_has_room(p, end, n)))  \
                         goto bad;                       \
         } while (0)