MT#55283 Fix for crash introduced by 6c03a44c

NFTNL_EXPR_TG_INFO actually expects the info data to be heap allocated
via malloc(), as it will free() it when the expression is freed via
nftnl_expr_free().

No symbol table info available.
No symbol table info available.
No symbol table info available.
No locals.
No locals.
        r = 0x55e087c75130
        err = <optimized out>
        err = <optimized out>
    args=args@entry=0x7ffc80943460) at ./nftables.c:593
        err = <optimized out>
        nl = 0x55e087c4add0
        seq = 1711621092
        err = 0x0
        nl = <optimized out>
        seq = <optimized out>
        err = <optimized out>
No locals.

Log:

rtpengine[269176]: INFO: [crypto] Generating new DTLS certificate
rtpengine[269176]: DEBUG: [crypto] Using EC-prime256v1 key for DTLS certificate
rtpengine[269176]: free(): invalid pointer
rtpengine[269792]: INFO: [crypto] Generating new DTLS certificate
rtpengine[269792]: DEBUG: [crypto] Using EC-prime256v1 key for DTLS certificate
rtpengine[269792]: free(): invalid pointer
rtpengine[270372]: INFO: [crypto] Generating new DTLS certificate
rtpengine[270372]: DEBUG: [crypto] Using EC-prime256v1 key for DTLS certificate
rtpengine[270372]: free(): invalid pointer
rtpengine[2487]: INFO: [crypto] Generating new DTLS certificate
rtpengine[2487]: DEBUG: [crypto] Using EC-prime256v1 key for DTLS certificate
rtpengine[2487]: free(): invalid pointer

Change-Id: Id67a4bb4cd3627d7ea6aed1b9f7d73b80ed676c8

daemon/nftables.c

@@ -54,9 +54,6 @@ struct add_rule_callbacks {
 	const char *base_chain;
 	int table;
 	bool append;
-
-	// intermediate storage area
-	struct xt_rtpengine_info rtpe_target_info;
 };
 
 
@@ -463,9 +460,12 @@ static const char *rtpe_target_base(struct nftnl_rule *r, struct add_rule_callba
 	nftnl_expr_set_str(e, NFTNL_EXPR_TG_NAME, "RTPENGINE");
 	nftnl_expr_set_u32(e, NFTNL_EXPR_TG_REV, 0);
 
-	callbacks->rtpe_target_info = (struct xt_rtpengine_info) { .id = callbacks->table };
+	struct xt_rtpengine_info *info = malloc(sizeof(*info));
+	if (!info)
+		return "failed to allocate target info for RTPENGINE";
+	*info = (__typeof__(*info)) { .id = callbacks->table };
 
-	nftnl_expr_set(e, NFTNL_EXPR_TG_INFO, &callbacks->rtpe_target_info, sizeof(callbacks->rtpe_target_info));
+	nftnl_expr_set(e, NFTNL_EXPR_TG_INFO, info, sizeof(*info));
 
 	nftnl_rule_add_expr(r, e);