From 7839990f9cdf34e55435ed90109e82709032466a Mon Sep 17 00:00:00 2001
From: Jan Friesse <jfriesse@redhat.com>
Date: Mon, 24 Mar 2025 12:05:08 +0100
Subject: [PATCH] totemsrp: Check size of orf_token msg

orf_token message is stored into preallocated array on endian convert
so carefully crafted malicious message can lead to crash of corosync.

Solution is to check message size beforehand.

Signed-off-by: Jan Friesse <jfriesse@redhat.com>
Reviewed-by: Christine Caulfield <ccaulfie@redhat.com>
---
 exec/totemsrp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/exec/totemsrp.c b/exec/totemsrp.c
index 962d0e2a..364528ce 100644
--- a/exec/totemsrp.c
+++ b/exec/totemsrp.c
@@ -3679,12 +3679,20 @@ static int check_orf_token_sanity(
 	const struct totemsrp_instance *instance,
 	const void *msg,
 	size_t msg_len,
+	size_t max_msg_len,
 	int endian_conversion_needed)
 {
 	int rtr_entries;
 	const struct orf_token *token = (const struct orf_token *)msg;
 	size_t required_len;
 
+	if (msg_len > max_msg_len) {
+		log_printf (instance->totemsrp_log_level_security,
+		    "Received orf_token message is too long...  ignoring.");
+
+		return (-1);
+	}
+
 	if (msg_len < sizeof(struct orf_token)) {
 		log_printf (instance->totemsrp_log_level_security,
 		    "Received orf_token message is too short...  ignoring.");
@@ -3698,6 +3706,13 @@ static int check_orf_token_sanity(
 		rtr_entries = token->rtr_list_entries;
 	}
 
+	if (rtr_entries > RETRANSMIT_ENTRIES_MAX) {
+		log_printf (instance->totemsrp_log_level_security,
+		    "Received orf_token message rtr_entries is corrupted...  ignoring.");
+
+		return (-1);
+	}
+
 	required_len = sizeof(struct orf_token) + rtr_entries * sizeof(struct rtr_item);
 	if (msg_len < required_len) {
 		log_printf (instance->totemsrp_log_level_security,
@@ -3866,7 +3881,8 @@ static int message_handler_orf_token (
 	"Time since last token %0.4f ms", ((float)tv_diff) / 1000000.0);
 #endif
 
-	if (check_orf_token_sanity(instance, msg, msg_len, endian_conversion_needed) == -1) {
+	if (check_orf_token_sanity(instance, msg, msg_len, sizeof(token_storage),
+            endian_conversion_needed) == -1) {
 		return (0);
 	}
 
