1 files changed, 23 insertions, 9 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index a297283154d5..246117142b5c 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -5154,7 +5154,7 @@ sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
          * The sender of the SHUTDOWN MAY also start an overall guard timer
          * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
          */
-        sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+        sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
                         SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
 
         if (asoc->autoclose)
@@ -5299,14 +5299,28 @@ sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
         SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
 
         if (asoc->overall_error_count >= asoc->max_retrans) {
-                sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
-                                SCTP_ERROR(ETIMEDOUT));
-                /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
-                sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
-                                SCTP_PERR(SCTP_ERROR_NO_ERROR));
-                SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
-                SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
-                return SCTP_DISPOSITION_DELETE_TCB;
+                if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
+                        /*
+                         * We are here likely because the receiver had its rwnd
+                         * closed for a while and we have not been able to
+                         * transmit the locally queued data within the maximum
+                         * retransmission attempts limit.  Start the T5
+                         * shutdown guard timer to give the receiver one last
+                         * chance and some additional time to recover before
+                         * aborting.
+                         */
+                        sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
+                                SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+                } else {
+                        sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+                                        SCTP_ERROR(ETIMEDOUT));
+                        /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
+                        sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+                                        SCTP_PERR(SCTP_ERROR_NO_ERROR));
+                        SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
+                        SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
+                        return SCTP_DISPOSITION_DELETE_TCB;
+                }
         }
 
         /* E1) For the destination address for which the timer