| From aded024a12b32fc1ed9a80639681daae2d07ec25 Mon Sep 17 00:00:00 2001 |
| From: Sjur Brændeland <sjur.brandeland@stericsson.com> |
| Date: Tue, 22 Jan 2013 09:50:26 +1030 |
| Subject: virtio_console: Don't access uninitialized data. |
| |
| From: Sjur Brændeland <sjur.brandeland@stericsson.com> |
| |
| commit aded024a12b32fc1ed9a80639681daae2d07ec25 upstream. |
| |
| Don't access uninitialized work-queue when removing device. |
| The work queue is initialized only if the device multi-queue. |
| So don't call cancel_work unless this is a multi-queue device. |
| |
| This fixes the following panic: |
| |
| Kernel panic - not syncing: BUG! |
| Call Trace: |
| 62031b28: [<6026085d>] panic+0x16b/0x2d3 |
| 62031b30: [<6004ef5e>] flush_work+0x0/0x1d7 |
| 62031b60: [<602606f2>] panic+0x0/0x2d3 |
| 62031b68: [<600333b0>] memcpy+0x0/0x140 |
| 62031b80: [<6002d58a>] unblock_signals+0x0/0x84 |
| 62031ba0: [<602609c5>] printk+0x0/0xa0 |
| 62031bd8: [<60264e51>] __mutex_unlock_slowpath+0x13d/0x148 |
| 62031c10: [<6004ef5e>] flush_work+0x0/0x1d7 |
| 62031c18: [<60050234>] try_to_grab_pending+0x0/0x17e |
| 62031c38: [<6004e984>] get_work_gcwq+0x71/0x8f |
| 62031c48: [<60050539>] __cancel_work_timer+0x5b/0x115 |
| 62031c78: [<628acc85>] unplug_port+0x0/0x191 [virtio_console] |
| 62031c98: [<6005061c>] cancel_work_sync+0x12/0x14 |
| 62031ca8: [<628ace96>] virtcons_remove+0x80/0x15c [virtio_console] |
| 62031ce8: [<628191de>] virtio_dev_remove+0x1e/0x7e [virtio] |
| 62031d08: [<601cf242>] __device_release_driver+0x75/0xe4 |
| 62031d28: [<601cf2dd>] device_release_driver+0x2c/0x40 |
| 62031d48: [<601ce0dd>] driver_unbind+0x7d/0xc6 |
| 62031d88: [<601cd5d9>] drv_attr_store+0x27/0x29 |
| 62031d98: [<60115f61>] sysfs_write_file+0x100/0x14d |
| 62031df8: [<600b737d>] vfs_write+0xcb/0x184 |
| 62031e08: [<600b58b8>] filp_close+0x88/0x94 |
| 62031e38: [<600b7686>] sys_write+0x59/0x88 |
| 62031e88: [<6001ced1>] handle_syscall+0x5d/0x80 |
| 62031ea8: [<60030a74>] userspace+0x405/0x531 |
| 62031f08: [<600d32cc>] sys_dup+0x0/0x5e |
| 62031f28: [<601b11d6>] strcpy+0x0/0x18 |
| 62031f38: [<600be46c>] do_execve+0x10/0x12 |
| 62031f48: [<600184c7>] run_init_process+0x43/0x45 |
| 62031fd8: [<60019a91>] new_thread_handler+0xba/0xbc |
| |
| Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com> |
| Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/char/virtio_console.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/char/virtio_console.c |
| +++ b/drivers/char/virtio_console.c |
| @@ -1966,7 +1966,8 @@ static void virtcons_remove(struct virti |
| /* Disable interrupts for vqs */ |
| vdev->config->reset(vdev); |
| /* Finish up work that's lined up */ |
| - cancel_work_sync(&portdev->control_work); |
| + if (use_multiport(portdev)) |
| + cancel_work_sync(&portdev->control_work); |
| |
| list_for_each_entry_safe(port, port2, &portdev->ports, list) |
| unplug_port(port); |
