diff options
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2014-11-04 13:40:11 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-07 10:21:44 -0800 |
| commit | 04a258c162a85c0f4ae56be67634dc43c9a4fa9b (patch) | |
| tree | 999f2bdac525ea05d75899169d97695021fd5a29 /drivers/char | |
| parent | 31d4ea1a093fcf668d5f95af44b8d41488bdb7ec (diff) | |
Drivers: hv: vmbus: Fix a race condition when unregistering a device
When build with Debug the following crash is sometimes observed:
Call Trace:
[<ffffffff812b9600>] string+0x40/0x100
[<ffffffff812bb038>] vsnprintf+0x218/0x5e0
[<ffffffff810baf7d>] ? trace_hardirqs_off+0xd/0x10
[<ffffffff812bb4c1>] vscnprintf+0x11/0x30
[<ffffffff8107a2f0>] vprintk+0xd0/0x5c0
[<ffffffffa0051ea0>] ? vmbus_process_rescind_offer+0x0/0x110 [hv_vmbus]
[<ffffffff8155c71c>] printk+0x41/0x45
[<ffffffffa004ebac>] vmbus_device_unregister+0x2c/0x40 [hv_vmbus]
[<ffffffffa0051ecb>] vmbus_process_rescind_offer+0x2b/0x110 [hv_vmbus]
...
This happens due to the following race: between 'if (channel->device_obj)' check
in vmbus_process_rescind_offer() and pr_debug() in vmbus_device_unregister() the
device can disappear. Fix the issue by taking an additional reference to the
device before proceeding to vmbus_device_unregister().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/char')
0 files changed, 0 insertions, 0 deletions