usbnet: smsc95xx: Fix use-after-free after removal
[ Upstream commit b835a71ef64a61383c414d6bf2896d2c0161deca ]
Syzbot reports an use-after-free in workqueue context:
BUG: KASAN: use-after-free in mutex_unlock+0x19/0x40 kernel/locking/mutex.c:737
mutex_unlock+0x19/0x40 kernel/locking/mutex.c:737
__smsc95xx_mdio_read drivers/net/usb/smsc95xx.c:217 [inline]
smsc95xx_mdio_read+0x583/0x870 drivers/net/usb/smsc95xx.c:278
check_carrier+0xd1/0x2e0 drivers/net/usb/smsc95xx.c:644
process_one_work+0x777/0xf90 kernel/workqueue.c:2274
worker_thread+0xa8f/0x1430 kernel/workqueue.c:2420
kthread+0x2df/0x300 kernel/kthread.c:255
It looks like that smsc95xx_unbind() is freeing the structures that are
still in use by the concurrently running workqueue callback. Thus switch
to using cancel_delayed_work_sync() to ensure the work callback really
is no longer active.
Reported-by: syzbot+29dc7d4ae19b703ff947@syzkaller.appspotmail.com
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
1 file changed
