CVE-2025-39711: media: ivsc: Fix crash at shutdown due to missing mei_cldev_disable() calls
In the Linux kernel, the following vulnerability has been resolved:
media: ivsc: Fix crash at shutdown due to missing meicldevdisable() calls
Both the ACE and CSI driver are missing a meicldevdisable() call in their remove() function.
This causes the meicl client to stay part of the meidevice->filelist list even though its memory is freed by meiclbusdevrelease() calling kfree(cldev->cl).
This leads to a use-after-free when meivscremove() runs meistop() which first removes all mei bus devices calling meiaceremove() and meicsiremove() followed by meiclbusdevrelease() and then calls meiclalldisconnect() which walks over meidevice->filelist dereferecing the just freed cldev->cl.
And meivscremove() it self is run at shutdown because of the platformdeviceunregister(tp->pdev) in vsctpshutdown()
When building a kernel with KASAN this leads to the following KASAN report:
[ 106.634504] ================================================================== [ 106.634623] BUG: KASAN: slab-use-after-free in meiclsetdisconnected (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]=UNSIGNEDMODULE [ 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] kasanreport (mm/kasan/report.c:221 mm/kasan/report.c:636) [ 106.634901] meiclsetdisconnected (drivers/misc/mei/client.c:783) mei [ 106.634921] meiclalldisconnect (drivers/misc/mei/client.c:2165 (discriminator 4)) mei [ 106.634941] meireset (drivers/misc/mei/init.c:163) mei ... [ 106.635042] meistop (drivers/misc/mei/init.c:348) mei [ 106.635062] meivscremove (drivers/misc/mei/meidev.h:784 drivers/misc/mei/platform-vsc.c:393) meivsc [ 106.635066] platformremove (drivers/base/platform.c:1424)
Add the missing meicldevdisable() calls so that the meicl gets removed from meidevice->filelist before it is freed to fix this.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Fix the use-after-free at shutdown by adding the missing mei_cldev_disable() calls so the mei_cl gets removed from mei_device->file_list before mei_cl_bus_dev_release() frees kfree(cldev->cl); also ensure mei_vsc_remove() (run at shutdown) no longer triggers mei_cl_all_disconnect() to dereference already-freed cldev->cl.
Linux kernel (mei) Add missing mei_cldev_disable() calls = Ensure mei_cldev_disable() is called for both ACE and CSI driver paths before mei_device->file_list is freed
Event History
Frequently Asked Questions
What is the severity of CVE-2025-39711?
CVE-2025-39711 is considered a medium severity vulnerability due to the potential for a system crash.
How do I fix CVE-2025-39711?
To fix CVE-2025-39711, ensure your Linux kernel is updated to the latest version that includes the mei_cldev_disable() calls.
What systems are affected by CVE-2025-39711?
CVE-2025-39711 affects the Linux kernel, specifically the ACE and CSI drivers.
What is the nature of the vulnerability in CVE-2025-39711?
CVE-2025-39711 is a vulnerability that causes a crash during shutdown due to missing calls that disable the mei_cl client.
Is there a workaround for CVE-2025-39711?
There are no official workarounds for CVE-2025-39711, and updating the kernel is recommended for resolution.