From: "K. Y. Srinivasan" <kys@microsoft.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com,
vkuznets@redhat.com
Cc: Vitaly Kuznetsov
<"[mailto:vkuznets@redhat.com]"@linuxonhyperv.com>,
"K. Y. Srinivasan" <kys@microsoft.com>
Subject: [PATCH 04/16] Drivers: hv: vmbus: avoid double kfree for device_obj
Date: Tue, 3 Feb 2015 18:26:32 -0800 [thread overview]
Message-ID: <1423016804-22014-4-git-send-email-kys@microsoft.com> (raw)
In-Reply-To: <1423016804-22014-1-git-send-email-kys@microsoft.com>
From: Vitaly Kuznetsov <[mailto:vkuznets@redhat.com]>
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>
---
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);
}
}
--
1.7.4.1
next prev parent reply other threads:[~2015-02-04 1:17 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-04 2:26 [PATCH 00/16] Drivers: hv: vmbus: Miscellaneous fixes/enhancements K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 01/16] Drivers: hv: vmbus: prevent cpu offlining on newer hypervisors K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 02/16] Drivers: hv: vmbus: rename channel work queues K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 03/16] drivers:hv:vmbus drivers:hv:vmbus Allow for more than one MMIO range for children K. Y. Srinivasan
2015-02-04 2:26 ` K. Y. Srinivasan [this message]
2015-02-04 2:26 ` [PATCH 05/16] Drivers: hv: vmbus: teardown hv_vmbus_con workqueue and vmbus_connection pages on shutdown K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 06/16] drivers: hv: vmbus: Teardown synthetic interrupt controllers on module unload K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 07/16] clockevents: export clockevents_unbind_device instead of clockevents_unbind K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 08/16] Drivers: hv: vmbus: Teardown clockevent devices on module unload K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 09/16] hv: hv_util: move vmbus_open() to a later place K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 10/16] hv: vmbus_post_msg: retry the hypercall on some transient errors K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 11/16] hv: vmbus_open(): reset the channel state on ENOMEM K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 12/16] hv: channel: match var type to return type of wait_for_completion K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 13/16] hv: channel_mgmt: " K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 14/16] hv: hv_balloon: " K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 15/16] Drivers: hv: vmbus: Fix a bug in the error path in vmbus_open() K. Y. Srinivasan
2015-02-04 2:26 ` [PATCH 16/16] Drivers: hv: vmbus: Add support for the NetworkDirect GUID K. Y. Srinivasan
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