| Message ID | 20221123132808.2090427-1-yangyingliang@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 369eb2c9f1f72adbe91e0ea8efb130f0a2ba11a6 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] net: phy: fix null-ptr-deref while probe() failed | expand |
Hello: This patch was applied to netdev/net.git (master) by David S. Miller <davem@davemloft.net>: On Wed, 23 Nov 2022 21:28:08 +0800 you wrote: > I got a null-ptr-deref report as following when doing fault injection test: > > BUG: kernel NULL pointer dereference, address: 0000000000000058 > Oops: 0000 [#1] PREEMPT SMP KASAN PTI > CPU: 1 PID: 253 Comm: 507-spi-dm9051 Tainted: G B N 6.1.0-rc3+ > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 > RIP: 0010:klist_put+0x2d/0xd0 > Call Trace: > <TASK> > klist_remove+0xf1/0x1c0 > device_release_driver_internal+0x23e/0x2d0 > bus_remove_device+0x1bd/0x240 > device_del+0x357/0x770 > phy_device_remove+0x11/0x30 > mdiobus_unregister+0xa5/0x140 > release_nodes+0x6a/0xa0 > devres_release_all+0xf8/0x150 > device_unbind_cleanup+0x19/0xd0 > > [...] Here is the summary with links: - [net] net: phy: fix null-ptr-deref while probe() failed https://git.kernel.org/netdev/net/c/369eb2c9f1f7 You are awesome, thank you!
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 57849ac0384e..a72adabfd2a7 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1520,6 +1520,7 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, error_module_put: module_put(d->driver->owner); + d->driver = NULL; error_put_device: put_device(d); if (ndev_owner != bus->owner)
I got a null-ptr-deref report as following when doing fault injection test: BUG: kernel NULL pointer dereference, address: 0000000000000058 Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 PID: 253 Comm: 507-spi-dm9051 Tainted: G B N 6.1.0-rc3+ Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:klist_put+0x2d/0xd0 Call Trace: <TASK> klist_remove+0xf1/0x1c0 device_release_driver_internal+0x23e/0x2d0 bus_remove_device+0x1bd/0x240 device_del+0x357/0x770 phy_device_remove+0x11/0x30 mdiobus_unregister+0xa5/0x140 release_nodes+0x6a/0xa0 devres_release_all+0xf8/0x150 device_unbind_cleanup+0x19/0xd0 //probe path: phy_device_register() device_add() phy_connect phy_attach_direct() //set device driver probe() //it's failed, driver is not bound device_bind_driver() // probe failed, it's not called //remove path: phy_device_remove() device_del() device_release_driver_internal() __device_release_driver() //dev->drv is not NULL klist_remove() <- knode_driver is not added yet, cause null-ptr-deref In phy_attach_direct(), after setting the 'dev->driver', probe() fails, device_bind_driver() is not called, so the knode_driver->n_klist is not set, then it causes null-ptr-deref in __device_release_driver() while deleting device. Fix this by setting dev->driver to NULL in the error path in phy_attach_direct(). Fixes: e13934563db0 ("[PATCH] PHY Layer fixup") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/net/phy/phy_device.c | 1 + 1 file changed, 1 insertion(+)