| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 69/90] batman-adv: Fix refcnt leak in batadv_show_throughput_override | Date | Wed, 13 May 2020 11:45:05 +0200 |
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From: Xiyu Yang <xiyuyang19@fudan.edu.cn>
commit f872de8185acf1b48b954ba5bd8f9bc0a0d14016 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_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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/batman-adv/sysfs.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1190,6 +1190,7 @@ static ssize_t batadv_show_throughput_ov 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); }
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