From 13f968c8b762e217087a657ee7560dc31170b99f Mon Sep 17 00:00:00 2001 From: Xiyu Yang Date: Wed, 15 Apr 2020 16:35:21 +0800 Subject: [PATCH] batman-adv: Fix refcnt leak in batadv_store_throughput_override commit 6107c5da0fca8b50b4d3215e94d619d38cc4a18c upstream. 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: 0b5ecc6811bd ("batman-adv: add throughput override attribute to hard_ifaces") Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index eb6a98d..079a134 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1150,7 +1150,7 @@ 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) -- 2.7.4