2.6 KiB
CVE-2025-39711
Description
In the Linux kernel, the following vulnerability has been resolved:media: ivsc: Fix crash at shutdown due to missing mei_cldev_disable() callsBoth the ACE and CSI driver are missing a mei_cldev_disable() call intheir remove() function.This causes the mei_cl client to stay part of the mei_device->file_listlist even though its memory is freed by mei_cl_bus_dev_release() callingkfree(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() andmei_csi_remove() followed by mei_cl_bus_dev_release() and then callsmei_cl_all_disconnect() which walks over mei_device->file_list dereferecingthe just freed cldev->cl.And mei_vsc_remove() it self is run at shutdown because of theplatform_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] ...[ 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 removedfrom mei_device->file_list before it is freed to fix this.
POC
Reference
No PoCs from references.