From c224405c31688d351ed79a304fa491517f541191 Mon Sep 17 00:00:00 2001
From: John Thacker <johnthacker@gmail.com>
Date: Sun, 19 Mar 2023 15:16:39 -0400
Subject: [PATCH] RPCoRDMA: Frame end cleanup for global write offsets

Add a frame end routine for a global which is assigned to packet
scoped memory. It really should be made proto data, but is used
in a function in the header (that doesn't take the packet info
struct as an argument) and this fix needs to be made in stable
branches.

Fix #18852


(cherry picked from commit 3c8be14c827f1587da3c2b3bb0d9c04faff57413)
---
 epan/dissectors/packet-rpcrdma.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/epan/dissectors/packet-rpcrdma.c b/epan/dissectors/packet-rpcrdma.c
index 177e772c44b..815f6a3fc76 100644
--- a/epan/dissectors/packet-rpcrdma.c
+++ b/epan/dissectors/packet-rpcrdma.c
@@ -24,6 +24,7 @@
 #include <epan/addr_resolv.h>
 
 #include "packet-rpcrdma.h"
+#include "packet-frame.h"
 #include "packet-infiniband.h"
 #include "packet-iwarp-ddp-rdmap.h"
 
@@ -271,6 +272,18 @@ void rpcrdma_insert_offset(gint offset)
     wmem_array_append_one(gp_rdma_write_offsets, offset);
 }
 
+/*
+ * Reset the array of write offsets at the end of the frame. These
+ * are packet scoped, so they don't need to be freed, but we want
+ * to ensure that the global doesn't point to no longer allocated
+ * memory in a later packet.
+ */
+static void
+reset_write_offsets(void)
+{
+    gp_rdma_write_offsets = NULL;
+}
+
 /* Get conversation state, it is created if it does not exist */
 static rdma_conv_info_t *get_rdma_conv_info(packet_info *pinfo)
 {
@@ -1409,6 +1422,7 @@ dissect_rpcrdma(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data
             if (write_size > 0 && !pinfo->fd->visited) {
                 /* Initialize array of write chunk offsets */
                 gp_rdma_write_offsets = wmem_array_new(wmem_packet_scope(), sizeof(gint));
+                register_frame_end_routine(pinfo, reset_write_offsets);
                 TRY {
                     /*
                      * Call the upper layer dissector to get a list of offsets
-- 
GitLab

