The following commit has been merged in the master branch: commit f872de8185acf1b48b954ba5bd8f9bc0a0d14016 Author: Xiyu Yang xiyuyang19@fudan.edu.cn Date: Wed Apr 15 16:31:50 2020 +0800

batman-adv: Fix refcnt leak in batadv_show_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_show_throughput_override() returns, "hard_iface" becomes invalid, so the refcount should be decreased to keep refcount balanced.

The issue happens in the normal path of batadv_show_throughput_override(), which forgets to decrease the refcnt increased by batadv_hardif_get_by_netdev() before the function returns, causing a refcnt leak.

Fix this issue by calling batadv_hardif_put() before the batadv_show_throughput_override() returns in the normal path.

Fixes: 0b5ecc6811bd ("batman-adv: add throughput override attribute to hard_ifaces") Signed-off-by: Xiyu Yang xiyuyang19@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de

diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index c45962d8527b..c0b00268aac4 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1190,6 +1190,7 @@ static ssize_t batadv_show_throughput_override(struct kobject *kobj,

tp_override = atomic_read(&hard_iface->bat_v.throughput_override);

+ batadv_hardif_put(hard_iface); return sprintf(buff, "%u.%u MBit\n", tp_override / 10, tp_override % 10); }