svn commit: r360745 - stable/11/sys/netinet

[Michael Tuexen]

Author: tuexen
Date: Thu May  7 02:13:28 2020
New Revision: 360745
URL: https://svnweb.freebsd.org/changeset/base/360745

Log:
  MFC r353145: Plump a memory leak
  
  Plumb an mbuf leak in a code path that should not be taken. Also avoid
  that this path is taken by setting the tail pointer correctly.
  There is still bug related to handling unordered unfragmented messages
  which were delayed in deferred handling.
  This issue was found by OSS-Fuzz testing the usrsctp stack and reported in
  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=17794

Modified:
  stable/11/sys/netinet/sctp_indata.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/netinet/sctp_indata.c
==============================================================================
--- stable/11/sys/netinet/sctp_indata.c	Thu May  7 02:10:44 2020	(r360744)
+++ stable/11/sys/netinet/sctp_indata.c	Thu May  7 02:13:28 2020	(r360745)
@@ -714,6 +714,7 @@ sctp_add_to_tail_pointer(struct sctp_queued_to_read *c
 	}
 	if (control->tail_mbuf == NULL) {
 		/* TSNH */
+		sctp_m_freem(control->data);
 		control->data = m;
 		sctp_setup_tail_pointer(control);
 		return;
@@ -2117,10 +2118,13 @@ sctp_process_a_data_chunk(struct sctp_tcb *stcb, struc
 			struct mbuf *mm;
 
 			control->data = dmbuf;
+			control->tail_mbuf = NULL;
 			for (mm = control->data; mm; mm = mm->m_next) {
 				control->length += SCTP_BUF_LEN(mm);
+				if (SCTP_BUF_NEXT(mm) == NULL) {
+					control->tail_mbuf = mm;
+				}
 			}
-			control->tail_mbuf = NULL;
 			control->end_added = 1;
 			control->last_frag_seen = 1;
 			control->first_frag_seen = 1;