From: Saurabh Sengar Date: Thu, 29 Aug 2024 07:13:11 +0000 (+0530) Subject: uio_hv_generic: Fix kernel NULL pointer dereference in hv_uio_rescind X-Git-Tag: v6.11-rc7~3^2~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb1adbd7e50f3d2de56d0a2bb0700e2e819a329e;p=thirdparty%2Flinux.git uio_hv_generic: Fix kernel NULL pointer dereference in hv_uio_rescind 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: ca3cda6fcf1e ("uio_hv_generic: add rescind support") Signed-off-by: Saurabh Sengar Signed-off-by: Naman Jain Link: https://lore.kernel.org/r/20240829071312.1595-2-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c index b45653752301d..e3e66a3e85a81 100644 --- a/drivers/uio/uio_hv_generic.c +++ b/drivers/uio/uio_hv_generic.c @@ -106,10 +106,11 @@ static void hv_uio_channel_cb(void *context) /* * Callback from vmbus_event when channel is rescinded.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); /*