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authorPrashant Malani <pmalani@chromium.org>2019-11-20 11:40:21 -0800
committerDavid S. Miller <davem@davemloft.net>2019-11-20 12:48:13 -0800
commit84811412464d66fcf73661a279aa1d7985166495 (patch)
tree9929dd11897149a19c3cf6ec9b04d2d888e4e28e /drivers/net/usb
parentb172845a4090e52f233e45801ce7f44ecc4cc955 (diff)
downloadlinux-84811412464d66fcf73661a279aa1d7985166495.tar.bz2
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>
Diffstat (limited to 'drivers/net/usb')
-rw-r--r--drivers/net/usb/r8152.c2
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);