system-linux: fix memory leak on error in system_if_check

Detected by Coverity CID 1330302

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

diff --git a/system-linux.c b/system-linux.c
index 27c0f1e3416baaece91579dd32cf66daf87ce805..611acb882d4db0fe2f4444f65217ba685d6d4721 100644 (file)
--- a/system-linux.c
+++ b/system-linux.c
@@ -1295,10 +1295,13 @@ int system_if_check(struct device *dev)
        int ret = 1;
 
        msg = nlmsg_alloc_simple(RTM_GETLINK, 0);
-       if (!msg || nlmsg_append(msg, &ifi, sizeof(ifi), 0) ||
-           nla_put_string(msg, IFLA_IFNAME, dev->ifname))
+       if (!msg)
                goto out;
 
+       if (nlmsg_append(msg, &ifi, sizeof(ifi), 0) ||
+           nla_put_string(msg, IFLA_IFNAME, dev->ifname))
+               goto free;
+
        nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, cb_if_check_valid, &chk);
        nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, cb_if_check_ack, &chk);
        nl_cb_err(cb, NL_CB_CUSTOM, cb_if_check_error, &chk);
@@ -1307,9 +1310,10 @@ int system_if_check(struct device *dev)
        while (chk.pending > 0)
                nl_recvmsgs(sock_rtnl, cb);
 
-       nlmsg_free(msg);
        ret = chk.pending;
 
+free:
+       nlmsg_free(msg);
 out:
        nl_cb_put(cb);
        return ret;