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author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2015-02-27 19:25:53 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-02 03:29:05 (GMT) |
commit | adcde069a85cb6674bdcf5f49f434d18b2db6e58 (patch) | |
tree | 557870ef82a87fa9c56fc3daa11355a78df92797 | |
parent | bc63b6f634d91a0b2a7f3ba4f266e55fec369de3 (diff) | |
download | linux-adcde069a85cb6674bdcf5f49f434d18b2db6e58.tar.xz |
Drivers: hv: vmbus: avoid double kfree for device_obj
On driver shutdown device_obj is being freed twice:
1) In vmbus_free_channels()
2) vmbus_device_release() (which is being triggered by device_unregister() in
vmbus_device_unregister().
This double kfree leads to the following sporadic crash on driver unload:
[ 23.469876] general protection fault: 0000 [#1] SMP
[ 23.470036] Modules linked in: hv_vmbus(-)
[ 23.470036] CPU: 2 PID: 213 Comm: rmmod Not tainted 3.19.0-rc5_bug923184+ #488
[ 23.470036] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS 090006 05/23/2012
[ 23.470036] task: ffff880036ef1cb0 ti: ffff880036ce8000 task.ti: ffff880036ce8000
[ 23.470036] RIP: 0010:[<ffffffff811d2e1b>] [<ffffffff811d2e1b>] __kmalloc_node_track_caller+0xdb/0x1e0
[ 23.470036] RSP: 0018:ffff880036cebcc8 EFLAGS: 00010246
...
When this crash does not happen on driver unload the similar one is expected if
we try to load hv_vmbus again.
Remove kfree from vmbus_free_channels() as freeing it from
vmbus_device_release() seems right.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/hv/channel_mgmt.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index ba4b25f..36bacc7 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -262,7 +262,6 @@ void vmbus_free_channels(void) list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { vmbus_device_unregister(channel->device_obj); - kfree(channel->device_obj); free_channel(channel); } } |