From: Douglas Anderson dianders@chromium.org
stable inclusion from stable-v6.6.7 commit 8defe1643dd36219c552752d417c34a073592984 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8SSQ4
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
[ Upstream commit e62adaeecdc6a1e8ae86e7f3f9f8223a3ede94f5 ]
As of commit d9962b0d4202 ("r8152: Block future register access if register access fails") there is a race condition that can happen between the USB device reset thread and napi_enable() (not) getting called during rtl8152_open(). Specifically: * While rtl8152_open() is running we get a register access error that's _not_ -ENODEV and queue up a USB reset. * rtl8152_open() exits before calling napi_enable() due to any reason (including usb_submit_urb() returning an error).
In that case: * Since the USB reset is perform in a separate thread asynchronously, it can run at anytime USB device lock is not held - even before rtl8152_open() has exited with an error and caused __dev_open() to clear the __LINK_STATE_START bit. * The rtl8152_pre_reset() will notice that the netif_running() returns true (since __LINK_STATE_START wasn't cleared) so it won't exit early. * rtl8152_pre_reset() will then hang in napi_disable() because napi_enable() was never called.
We can fix the race by making sure that the r8152 reset routines don't run at the same time as we're opening the device. Specifically we need the reset routines in their entirety rely on the return value of netif_running(). The only way to reliably depend on that is for them to hold the rntl_lock() mutex for the duration of reset.
Grabbing the rntl_lock() mutex for the duration of reset seems like a long time, but reset is not expected to be common and the rtnl_lock() mutex is already held for long durations since the core grabs it around the open/close calls.
Fixes: d9962b0d4202 ("r8152: Block future register access if register access fails") Reviewed-by: Grant Grundler grundler@chromium.org Signed-off-by: Douglas Anderson dianders@chromium.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/net/usb/r8152.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index be18d72cefcc..77408265e612 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -8364,6 +8364,8 @@ static int rtl8152_pre_reset(struct usb_interface *intf) struct r8152 *tp = usb_get_intfdata(intf); struct net_device *netdev;
+ rtnl_lock(); + if (!tp || !test_bit(PROBED_WITH_NO_ERRORS, &tp->flags)) return 0;
@@ -8395,20 +8397,17 @@ static int rtl8152_post_reset(struct usb_interface *intf) struct sockaddr sa;
if (!tp || !test_bit(PROBED_WITH_NO_ERRORS, &tp->flags)) - return 0; + goto exit;
rtl_set_accessible(tp);
/* reset the MAC address in case of policy change */ - if (determine_ethernet_addr(tp, &sa) >= 0) { - rtnl_lock(); + if (determine_ethernet_addr(tp, &sa) >= 0) dev_set_mac_address (tp->netdev, &sa, NULL); - rtnl_unlock(); - }
netdev = tp->netdev; if (!netif_running(netdev)) - return 0; + goto exit;
set_bit(WORK_ENABLE, &tp->flags); if (netif_carrier_ok(netdev)) { @@ -8427,6 +8426,8 @@ static int rtl8152_post_reset(struct usb_interface *intf) if (!list_empty(&tp->rx_done)) napi_schedule(&tp->napi);
+exit: + rtnl_unlock(); return 0; }