From: Florian Westphal <fw@strlen.de>
Date: Wed, 21 Jan 2026 13:33:21 +0000 (+0100)
Subject: monitor: fix memleak in setelem cb
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d2a427c4abfadd2ce51bdab54c40fbf3d990c724;p=thirdparty%2Fnftables.git

monitor: fix memleak in setelem cb

since 4521732ebbf3 ("monitor: missing cache and set handle initialization")
these fields are set via handle_merge(), so don't clobber those
fields in json output case:

==31877==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 16 byte(s) in 2 object(s) allocated from:
 #0 0x7f0cb9f29d4b in strdup asan/asan_interceptors.cpp:593
 #1 0x7f0cb9b584fd in xstrdup src/utils.c:80
 #2 0x7f0cb9b355b3 in handle_merge src/rule.c:127
 #3 0x7f0cb9ae12b8 in netlink_events_setelem_cb src/monitor.c:457

Seen when running tests/monitor with asan enabled.

Fixes: 4521732ebbf3 ("monitor: missing cache and set handle initialization")
Signed-off-by: Florian Westphal <fw@strlen.de>
---

diff --git a/src/monitor.c b/src/monitor.c
index fafeeebe..6532c9c5 100644
--- a/src/monitor.c
+++ b/src/monitor.c
@@ -496,13 +496,7 @@ static int netlink_events_setelem_cb(const struct nlmsghdr *nlh, int type,
 		nft_mon_print(monh, "\n");
 		break;
 	case NFTNL_OUTPUT_JSON:
-		dummyset->handle.family = family;
-		dummyset->handle.set.name = setname;
-		dummyset->handle.table.name = table;
 		monitor_print_element_json(monh, cmd, dummyset);
-		/* prevent set_free() from trying to free those */
-		dummyset->handle.set.name = NULL;
-		dummyset->handle.table.name = NULL;
 		if (!nft_output_echo(&monh->ctx->nft->output))
 			nft_mon_print(monh, "\n");
 		break;