forked from Minki/linux
543d7784b0
There is a race in the hub driver between hub_disconnect() and recursively_mark_NOTATTACHED(). This race can be triggered if the driver is unbound from a device at the same time as the bus's root hub is removed. When the race occurs, it can cause an oops: BUG: unable to handle kernel NULL pointer dereference at 0000015c IP: [<c16d5fb0>] recursively_mark_NOTATTACHED+0x20/0x60 Call Trace: [<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60 [<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60 [<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60 [<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60 [<c16d6082>] usb_set_device_state+0x92/0x120 [<c16d862b>] usb_disconnect+0x2b/0x1a0 [<c16dd4c0>] usb_remove_hcd+0xb0/0x160 [<c19ca846>] ? _raw_spin_unlock_irqrestore+0x26/0x50 [<c1704efc>] ehci_mid_remove+0x1c/0x30 [<c1704f26>] ehci_mid_stop_host+0x16/0x30 [<c16f7698>] penwell_otg_work+0xd28/0x3520 [<c19c945b>] ? __schedule+0x39b/0x7f0 [<c19cdb9d>] ? sub_preempt_count+0x3d/0x50 [<c125e97d>] process_one_work+0x11d/0x3d0 [<c19c7f4d>] ? mutex_unlock+0xd/0x10 [<c125e0e5>] ? manage_workers.isra.24+0x1b5/0x270 [<c125f009>] worker_thread+0xf9/0x320 [<c19ca846>] ? _raw_spin_unlock_irqrestore+0x26/0x50 [<c125ef10>] ? rescuer_thread+0x2b0/0x2b0 [<c1264ac4>] kthread+0x94/0xa0 [<c19d0f77>] ret_from_kernel_thread+0x1b/0x28 [<c1264a30>] ? kthread_create_on_node+0xc0/0xc0 One problem is that recursively_mark_NOTATTACHED() uses the intfdata value and hub->hdev->maxchild while hub_disconnect() is clearing them. Another problem is that it uses hub->ports[i] while the port device is being released. To fix this race, we need to hold the device_state_lock while hub_disconnect() changes the values. (Note that usb_disconnect() and hub_port_connect_change() already acquire this lock at similar critical times during a USB device's life cycle.) We also need to remove the port devices after maxchild has been set to 0, instead of before. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: "Du, Changbin" <changbinx.du@intel.com> Tested-by: "Du, Changbin" <changbinx.du@intel.com> CC: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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| .. | ||
| buffer.c | ||
| config.c | ||
| devices.c | ||
| devio.c | ||
| driver.c | ||
| endpoint.c | ||
| file.c | ||
| generic.c | ||
| hcd-pci.c | ||
| hcd.c | ||
| hub.c | ||
| hub.h | ||
| Kconfig | ||
| Makefile | ||
| message.c | ||
| notify.c | ||
| otg_whitelist.h | ||
| port.c | ||
| quirks.c | ||
| sysfs.c | ||
| urb.c | ||
| usb-acpi.c | ||
| usb.c | ||
| usb.h | ||