fs: dlm: change allocation limits

While running tcpkill I experienced invalid header length values while receiving to check that a node doesn't try to send a invalid dlm message we also check on applications minimum allocation limit. Also use DEFAULT_BUFFER_SIZE as maximum allocation limit. The define LOWCOMMS_MAX_TX_BUFFER_LEN is to calculate maximum buffer limits on application layer, future midcomms layer will subtract their needs from this define. Signed-off-by: Alexander Aring <[email protected]> Signed-off-by: David Teigland <[email protected]>
vieko · Mar 9, 2021 · c45674f · c45674f
1 parent 5174616
commit c45674f
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
@@ -1376,9 +1376,11 @@ void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
 	struct writequeue_entry *e;
 	int offset = 0;
 
-	if (len > LOWCOMMS_MAX_TX_BUFFER_LEN) {
-		BUILD_BUG_ON(PAGE_SIZE < LOWCOMMS_MAX_TX_BUFFER_LEN);
+	if (len > DEFAULT_BUFFER_SIZE ||
+	    len < sizeof(struct dlm_header)) {
+		BUILD_BUG_ON(PAGE_SIZE < DEFAULT_BUFFER_SIZE);
 		log_print("failed to allocate a buffer of size %d", len);
+		WARN_ON(1);
 		return NULL;
 	}