From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
To: linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org
Cc: "K . Y . Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
Michael Kelley <mikelley@microsoft.com>,
Juan Vazquez <juvazq@microsoft.com>,
Saruhan Karademir <skarade@microsoft.com>,
"Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Subject: [PATCH v2 5/7] Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind()
Date: Wed, 2 Dec 2020 10:22:12 +0100 [thread overview]
Message-ID: <20201202092214.13520-6-parri.andrea@gmail.com> (raw)
In-Reply-To: <20201202092214.13520-1-parri.andrea@gmail.com>
When channel->device_obj is non-NULL, vmbus_onoffer_rescind() could
invoke put_device(), that will eventually release the device and free
the channel object (cf. vmbus_device_release()). However, a pointer
to the object is dereferenced again later to load the primary_channel.
The use-after-free can be avoided by noticing that this load/check is
redundant if device_obj is non-NULL: primary_channel must be NULL if
device_obj is non-NULL, cf. vmbus_add_channel_work().
Fixes: 54a66265d6754b ("Drivers: hv: vmbus: Fix rescind handling")
Reported-by: Juan Vazquez <juvazq@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
---
Changes since v1:
- Fix typo in commit message
- Add Fixes: tag
drivers/hv/channel_mgmt.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 5bc5eef5da159..4072fd1f22146 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -1116,8 +1116,7 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
vmbus_device_unregister(channel->device_obj);
put_device(dev);
}
- }
- if (channel->primary_channel != NULL) {
+ } else if (channel->primary_channel != NULL) {
/*
* Sub-channel is being rescinded. Following is the channel
* close sequence when initiated from the driveri (refer to
--
2.25.1
next prev parent reply other threads:[~2020-12-02 9:24 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 9:22 [PATCH v2 0/7] Drivers: hv: vmbus: More VMBus-hardening changes Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 1/7] Drivers: hv: vmbus: Initialize memory to be sent to the host Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 2/7] Drivers: hv: vmbus: Avoid double fetch of msgtype in vmbus_on_msg_dpc() Andrea Parri (Microsoft)
2020-12-02 12:22 ` Wei Liu
2020-12-02 13:37 ` Andrea Parri
2020-12-02 13:40 ` Wei Liu
2020-12-02 14:14 ` Andrea Parri
2020-12-02 9:22 ` [PATCH v2 3/7] Drivers: hv: vmbus: Avoid double fetch of payload_size " Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 4/7] Drivers: hv: vmbus: Copy the hv_message object " Andrea Parri (Microsoft)
2020-12-06 18:39 ` Michael Kelley
2020-12-06 21:33 ` Andrea Parri
2020-12-02 9:22 ` Andrea Parri (Microsoft) [this message]
2020-12-02 9:22 ` [PATCH v2 6/7] Drivers: hv: vmbus: Resolve race condition in vmbus_onoffer_rescind() Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 7/7] Drivers: hv: vmbus: Do not allow overwriting vmbus_connection.channels[] Andrea Parri (Microsoft)
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