LU-17504 build: fix lock_handle array-index-out-of-bounds

[fs/lustre-release.git] / lustre / ldlm / ldlm_request.c

diff --git a/lustre/ldlm/ldlm_request.c b/lustre/ldlm/ldlm_request.c
index e51cd98..8ae1c88 100644 (file)
--- a/lustre/ldlm/ldlm_request.c
+++ b/lustre/ldlm/ldlm_request.c
@@ -88,24 +88,21 @@ struct ldlm_async_args {
  * LDLM_LOCKREQ_HANDLE -1 slots are available.
  * Otherwise, LDLM_LOCKREQ_HANDLE slots are available.
  *
- * \param[in] count
- * \param[in] type
+ * \param[in] count - total number of lock handles to include for cancel
+ * \param[in] type  - LDLM RPC request type
  *
  * \retval size of the request buffer
  */
 static int ldlm_request_bufsize(int count, int type)
 {
-       int avail = LDLM_LOCKREQ_HANDLES;
-
        if (type == LDLM_ENQUEUE)
-               avail -= LDLM_ENQUEUE_CANCEL_OFF;
+               count++;
 
-       if (count > avail)
-               avail = (count - avail) * sizeof(struct lustre_handle);
-       else
-               avail = 0;
+       /* keep minimum handles to keep struct size for compatibility */
+       if (count < LDLM_LOCKREQ_HANDLES)
+               count = LDLM_LOCKREQ_HANDLES;
 
-       return sizeof(struct ldlm_request) + avail;
+       return offsetof(struct ldlm_request, lock_handle[count]);
 }
 
 static void ldlm_expired_completion_wait(struct lock_wait_data *lwd)