pimd: prevent invalid memory access

Signalize termination to functions so they can avoid accessing pointers that might be no longer available. Signed-off-by: Rafael Zalamena <[email protected]>
FRRouting · Sep 29, 2024 · 8c6f606 · 8c6f606
1 parent 2e52de3
commit 8c6f606
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diff --git a/pimd/pim_instance.c b/pimd/pim_instance.c
@@ -26,6 +26,8 @@
 
 static void pim_instance_terminate(struct pim_instance *pim)
 {
+	pim->stopping = true;
+
 	pim_vxlan_exit(pim);
 
 	if (pim->ssm_info) {

diff --git a/pimd/pim_instance.h b/pimd/pim_instance.h
@@ -192,6 +192,8 @@ struct pim_instance {
 
 	uint64_t gm_rx_drop_sys;
 
+	bool stopping;
+
 #if PIM_IPV == 6
 	struct {
 		/** Embedded RP enable state. */

diff --git a/pimd/pim_tib.c b/pimd/pim_tib.c
@@ -181,7 +181,14 @@ void tib_sg_gm_prune(struct pim_instance *pim, pim_sgaddr sg,
 	 Making the call to pim_channel_del_oif and ignoring the return code
 	 fixes the issue without ill effect, similar to
 	 pim_forward_stop below.
+
+	 Also on shutdown when the PIM upstream is removed the channel removal
+	 may have already happened, so just return here instead of trying to
+	 access an invalid pointer.
 	*/
+	if (pim->stopping)
+		return;
+
 	result = pim_channel_del_oif(*oilp, oif, PIM_OIF_FLAG_PROTO_GM,
 				     __func__);
 	if (result) {