Commit 28a66432 authored by Saurabh Sengar's avatar Saurabh Sengar Committed by Cai Xinchen
Browse files

uio_hv_generic: Fix kernel NULL pointer dereference in hv_uio_rescind 

stable inclusion
from stable-v4.19.322
commit 3d414b64ecf6fd717d7510ffb893c6f23acbf50e
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IARWG0
CVE: CVE-2024-46739

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3d414b64ecf6fd717d7510ffb893c6f23acbf50e



--------------------------------

commit fb1adbd7e50f3d2de56d0a2bb0700e2e819a329e upstream.

For primary VM Bus channels, primary_channel pointer is always NULL. This
pointer is valid only for the secondary channels. Also, rescind callback
is meant for primary channels only.

Fix NULL pointer dereference by retrieving the device_obj from the parent
for the primary channel.

Cc: stable@vger.kernel.org
Fixes: ca3cda6f ("uio_hv_generic: add rescind support")
Signed-off-by: default avatarSaurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: default avatarNaman Jain <namjain@linux.microsoft.com>
Link: https://lore.kernel.org/r/20240829071312.1595-2-namjain@linux.microsoft.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarCai Xinchen <caixinchen1@huawei.com>
parent ecca3ab8

drivers/uio/uio_hv_generic.c

+2 −1
Original line number Diff line number Diff line
@@ -104,10 +104,11 @@ static void hv_uio_channel_cb(void *context) 


/*

 * Callback from vmbus_event when channel is rescinded.

 * It is meant for rescind of primary channels only.

 */

static void hv_uio_rescind(struct vmbus_channel *channel)

{

	struct hv_device *hv_dev = channel->primary_channel->device_obj;

	struct hv_device *hv_dev = channel->device_obj;

	struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev);



	/*