4.9-stable review patch. If anyone has any objections, please let me know.
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From: Jeremy Linton jeremy.linton@arm.com
[ Upstream commit e06513d78d54e6c7026c9043a39e2c01ee25bdbe ]
The smsc911x driver will crash if it is rmmod'ed while the netdev is up like:
Call trace: phy_detach+0x94/0x150 phy_disconnect+0x40/0x50 smsc911x_stop+0x104/0x128 [smsc911x] __dev_close_many+0xb4/0x138 dev_close_many+0xbc/0x190 rollback_registered_many+0x140/0x460 rollback_registered+0x68/0xb0 unregister_netdevice_queue+0x100/0x118 unregister_netdev+0x28/0x38 smsc911x_drv_remove+0x58/0x130 [smsc911x] platform_drv_remove+0x30/0x50 device_release_driver_internal+0x15c/0x1f8 driver_detach+0x54/0x98 bus_remove_driver+0x64/0xe8 driver_unregister+0x34/0x60 platform_driver_unregister+0x20/0x30 smsc911x_cleanup_module+0x14/0xbca8 [smsc911x] SyS_delete_module+0x1e8/0x238 __sys_trace_return+0x0/0x4
This is caused by the mdiobus being unregistered/free'd and the code in phy_detach() attempting to manipulate mdio related structures from unregister_netdev() calling close()
To fix this, we delay the mdiobus teardown until after the netdev is deregistered.
Reported-by: Matt Sealey matt.sealey@arm.com Signed-off-by: Jeremy Linton jeremy.linton@arm.com Reviewed-by: Andrew Lunn andrew@lunn.ch Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/smsc/smsc911x.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/smsc/smsc911x.c +++ b/drivers/net/ethernet/smsc/smsc911x.c @@ -2330,14 +2330,14 @@ static int smsc911x_drv_remove(struct pl pdata = netdev_priv(dev); BUG_ON(!pdata); BUG_ON(!pdata->ioaddr); - WARN_ON(dev->phydev);
SMSC_TRACE(pdata, ifdown, "Stopping driver");
+ unregister_netdev(dev); + mdiobus_unregister(pdata->mii_bus); mdiobus_free(pdata->mii_bus);
- unregister_netdev(dev); res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "smsc911x-memory"); if (!res)