diff options
| author | Prashant Malani <pmalani@chromium.org> | 2019-11-20 11:40:21 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-11-20 12:48:13 -0800 |
| commit | 84811412464d66fcf73661a279aa1d7985166495 (patch) | |
| tree | 9929dd11897149a19c3cf6ec9b04d2d888e4e28e | |
| parent | b172845a4090e52f233e45801ce7f44ecc4cc955 (diff) | |
r8152: Re-order napi_disable in rtl8152_close
Both rtl_work_func_t() and rtl8152_close() call napi_disable().
Since the two calls aren't protected by a lock, if the close
function starts executing before the work function, we can get into a
situation where the napi_disable() function is called twice in
succession (first by rtl8152_close(), then by set_carrier()).
In such a situation, the second call would loop indefinitely, since
rtl8152_close() doesn't call napi_enable() to clear the NAPI_STATE_SCHED
bit.
The rtl8152_close() function in turn issues a
cancel_delayed_work_sync(), and so it would wait indefinitely for the
rtl_work_func_t() to complete. Since rtl8152_close() is called by a
process holding rtnl_lock() which is requested by other processes, this
eventually leads to a system deadlock and crash.
Re-order the napi_disable() call to occur after the work function
disabling and urb cancellation calls are issued.
Change-Id: I6ef0b703fc214998a037a68f722f784e1d07815e
Reported-by: http://crbug.com/1017928
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/usb/r8152.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index d4a95b50bda6..4d34c01826f3 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -4283,10 +4283,10 @@ static int rtl8152_close(struct net_device *netdev) unregister_pm_notifier(&tp->pm_notifier); #endif tasklet_disable(&tp->tx_tl); - napi_disable(&tp->napi); clear_bit(WORK_ENABLE, &tp->flags); usb_kill_urb(tp->intr_urb); cancel_delayed_work_sync(&tp->schedule); + napi_disable(&tp->napi); netif_stop_queue(netdev); res = usb_autopm_get_interface(tp->intf); |