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| author | Andrea Parri (Microsoft) <parri.andrea@gmail.com> | 2020-12-09 08:08:25 +0100 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2021-02-05 09:55:42 +0000 |
| commit | e3fa4b747f085d2cda09bba0533b86fa76038635 (patch) | |
| tree | 1412fdb51d363f02a26b344d1cff661f084acfc4 | |
| parent | fe8c1b18a27de4d6ca5d99b3ffb3125dc69a5b76 (diff) | |
| download | linux-e3fa4b747f085d2cda09bba0533b86fa76038635.tar.gz linux-e3fa4b747f085d2cda09bba0533b86fa76038635.tar.bz2 linux-e3fa4b747f085d2cda09bba0533b86fa76038635.zip | |
Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind()
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>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-5-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 5bc5eef5da15..4072fd1f2214 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primary_channel != NULL) { /* * Sub-channel is being rescinded.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 |