From: Zhengchao Shao Date: Thu, 3 Nov 2022 09:09:05 +0000 (+0800) Subject: hamradio: fix issue of dev reference count leakage in bpq_device_event() X-Git-Tag: v4.9.334~69 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0bb5d753c06a782a0a79cf3b570ec6cd6c47b5bf;p=thirdparty%2Fkernel%2Fstable.git hamradio: fix issue of dev reference count leakage in bpq_device_event() [ Upstream commit 85cbaf032d3cd9f595152625eda5d4ecb1d6d78d ] When following tests are performed, it will cause dev reference counting leakage. a)ip link add bond2 type bond mode balance-rr b)ip link set bond2 up c)ifenslave -f bond2 rose1 d)ip link del bond2 When new bond device is created, the default type of the bond device is ether. And the bond device is up, bpq_device_event() receives the message and creates a new bpq device. In this case, the reference count value of dev is hold once. But after "ifenslave -f bond2 rose1" command is executed, the type of the bond device is changed to rose. When the bond device is unregistered, bpq_device_event() will not put the dev reference count. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Zhengchao Shao Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- diff --git a/drivers/net/hamradio/bpqether.c b/drivers/net/hamradio/bpqether.c index f5e0983ae2a11..7b766301189a7 100644 --- a/drivers/net/hamradio/bpqether.c +++ b/drivers/net/hamradio/bpqether.c @@ -551,7 +551,7 @@ static int bpq_device_event(struct notifier_block *this, if (!net_eq(dev_net(dev), &init_net)) return NOTIFY_DONE; - if (!dev_is_ethdev(dev)) + if (!dev_is_ethdev(dev) && !bpq_get_ax25_dev(dev)) return NOTIFY_DONE; switch (event) {