media: ivsc: Fix crash at shutdown due to missing mei_cldev_disable() calls

Both the ACE and CSI driver are missing a mei_cldev_disable() call in
their remove() function.

This causes the mei_cl client to stay part of the mei_device->file_list
list even though its memory is freed by mei_cl_bus_dev_release() calling
kfree(cldev->cl).

This leads to a use-after-free when mei_vsc_remove() runs mei_stop()
which first removes all mei bus devices calling mei_ace_remove() and
mei_csi_remove() followed by mei_cl_bus_dev_release() and then calls
mei_cl_all_disconnect() which walks over mei_device->file_list dereferecing
the just freed cldev->cl.

And mei_vsc_remove() it self is run at shutdown because of the
platform_device_unregister(tp->pdev) in vsc_tp_shutdown()

When building a kernel with KASAN this leads to the following KASAN report:

[ 106.634504] ==================================================================
[ 106.634623] BUG: KASAN: slab-use-after-free in mei_cl_set_disconnected (drivers/misc/mei/client.c:783) mei
[ 106.634683] Read of size 4 at addr ffff88819cb62018 by task systemd-shutdow/1
[ 106.634729]
[ 106.634767] Tainted: [E]=UNSIGNED_MODULE
[ 106.634770] Hardware name: Dell Inc. XPS 16 9640/09CK4V, BIOS 1.12.0 02/10/2025
[ 106.634773] Call Trace:
[ 106.634777]  <TASK>
...
[ 106.634871] kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:636)
[ 106.634901] mei_cl_set_disconnected (drivers/misc/mei/client.c:783) mei
[ 106.634921] mei_cl_all_disconnect (drivers/misc/mei/client.c:2165 (discriminator 4)) mei
[ 106.634941] mei_reset (drivers/misc/mei/init.c:163) mei
...
[ 106.635042] mei_stop (drivers/misc/mei/init.c:348) mei
[ 106.635062] mei_vsc_remove (drivers/misc/mei/mei_dev.h:784 drivers/misc/mei/platform-vsc.c:393) mei_vsc
[ 106.635066] platform_remove (drivers/base/platform.c:1424)

Add the missing mei_cldev_disable() calls so that the mei_cl gets removed
from mei_device->file_list before it is freed to fix this.

Fixes: 78876f71b3e9 ("media: pci: intel: ivsc: Add ACE submodule")
Fixes: 29006e196a56 ("media: pci: intel: ivsc: Add CSI submodule")
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

diff --git a/drivers/media/pci/intel/ivsc/mei_ace.c b/drivers/media/pci/intel/ivsc/mei_ace.c
index 3622271c71c8834bd21f78b3d6d5918d727a5515..50d18b627e152e2cd559f652d68026f815fd5792 100644 (file)
--- a/drivers/media/pci/intel/ivsc/mei_ace.c
+++ b/drivers/media/pci/intel/ivsc/mei_ace.c
@@ -529,6 +529,8 @@ static void mei_ace_remove(struct mei_cl_device *cldev)
 
        ace_set_camera_owner(ace, ACE_CAMERA_IVSC);
 
+       mei_cldev_disable(cldev);
+
        mutex_destroy(&ace->lock);
 }
 

diff --git a/drivers/media/pci/intel/ivsc/mei_csi.c b/drivers/media/pci/intel/ivsc/mei_csi.c
index 92d871a378ba248300063f43006680fac0d724c1..955f687e5d59c2e73a32fb6340e5fe8d6150d0c0 100644 (file)
--- a/drivers/media/pci/intel/ivsc/mei_csi.c
+++ b/drivers/media/pci/intel/ivsc/mei_csi.c
@@ -760,6 +760,8 @@ static void mei_csi_remove(struct mei_cl_device *cldev)
 
        pm_runtime_disable(&cldev->dev);
 
+       mei_cldev_disable(cldev);
+
        mutex_destroy(&csi->lock);
 }