From: Xiyu Yang Date: Wed, 15 Apr 2020 16:35:21 +0800 Subject: batman-adv: Fix refcnt leak in batadv_store_throughput_override batadv_show_throughput_override() invokes batadv_hardif_get_by_netdev(), which gets a batadv_hard_iface object from net_dev with increased refcnt and its reference is assigned to a local pointer 'hard_iface'. When batadv_store_throughput_override() returns, "hard_iface" becomes invalid, so the refcount should be decreased to keep refcount balanced. The issue happens in one error path of batadv_store_throughput_override(). When batadv_parse_throughput() returns NULL, the refcnt increased by batadv_hardif_get_by_netdev() is not decreased, causing a refcnt leak. Fix this issue by jumping to "out" label when batadv_parse_throughput() returns NULL. Fixes: c513176e4b7a ("batman-adv: add throughput override attribute to hard_ifaces") Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: Sven Eckelmann Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/b69cd8bdbfd6fa7e61878c2fa9e6637406f40dd9 diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index c20f2bab9db56021f7280ebdfc2afcfd772991bd..34e9948fbd45ef6f2690052a208d6a4e4a4f215b 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1149,7 +1149,7 @@ static ssize_t batadv_store_throughput_override(struct kobject *kobj, ret = batadv_parse_throughput(net_dev, buff, "throughput_override", &tp_override); if (!ret) - return count; + goto out; old_tp_override = atomic_read(&hard_iface->bat_v.throughput_override); if (old_tp_override == tp_override)