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CVE-2026-89870
media: zoran: Avoid freeing a registered video_device twice
Published 2026-09-16 (33 days ago) by the Linux kernel CNA. Subsystem drivers/media. Debian urgency: not yet assigned.
Debian does not build this code. The per-release build detail is under "Where it lives" below.
What to do, per Debian release
Debian's own status for CVE-2026-89870 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixedDLA-4841-1 · 2026-10-17 · text | 6.1.190-1 | Update the kernel and reboot. DLA-4841-1 shipped the fix on 2026-10-17, in 6.1.190-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixedDSA-6528-1 · 2026-09-29 · text | 6.12.111-1 | Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4817-1 · 2026-10-04 · text | 6.12.111-1~deb12u1 | Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
zoran_init_video_device() installs zoran_vdev_release() as the video_device release callback through zoran_template. After video_register_device() succeeds, video_unregister_device() drops the registered video_device reference and the V4L2 core eventually invokes that release callback, which kfree()s the video_device. zoran_exit_video_devices() called video_unregister_device() and then kfree(zr->video_dev), so device teardown could free the same video_device twice. Remove the direct kfree() and clear the cached pointer after unregistering. The pre-registration failure path keeps its manual free because the video_device was not registered there. This issue was found by a static analysis checker and confirmed by manual source review.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/media/pci/zoran/zoran_card.c
- What this is
- ZR36067 VIDEO FOR LINUX DRIVERMAINTAINERS section matched on drivers/media/pci/zoran/ · mjpeg-users@lists.sourceforge.net · Maintained
- Kernel module
- none to look for. The file would have gone into zr36067, and Debian does not compile it into that module, so finding zr36067 in lsmod would say nothing about this CVE.
Check it on the machine
grep -w CONFIG_VIDEO_ZORAN /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
Show whether Debian builds this, per release
Debian does not build this code. In 5 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.
- bookworm, trixie, forky, sid, bookworm · linux-6.12n
- n
- not enabled on any flavour - this release does not build the code
- Build switch
- CONFIG_VIDEO_ZORAN
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-09-16 (33 days ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.17%, higher than 5.8% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/media
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.18 | 6.1.188 | 3ad6cf275050 |
| 5.18 | 6.6.157 | c4acac8cdc00 |
| 5.18 | 6.12.110 | 4d99d8d0d895 |
| 5.18 | 6.18.51 | f1c4f3885df1 |
| 5.18 | 7.2.5 | 672dbccf4351 |
| 5.18 | 7.3 | 0735e0b5a967 |
| 5.10.110 | 0 | 0 |
| 5.15.33 | 0 | 0 |
| 5.16.19 | 0 | 0 |
| 5.17.2 | 0 | 0 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4841-1 | 2026-10-17 | bookworm 6.1.190-1 | tracker |
| DLA-4817-1 | 2026-10-04 | bookworm 6.12.111-1~deb12u1 | tracker |
| DSA-6528-1 | 2026-09-29 | trixie 6.12.111-1 | tracker |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The double-free is in zoran_exit_video_devices() on the ZR36057/36067 PCI MJPEG capture driver's zoran_remove() path (rmmod zr36067, PCI sysfs unbind, or hot-remove). It is reached from local driver teardown, not from network packets or a remote protocol.
- AC:LAttack complexity, low
- After a successful probe, zoran_remove() always calls video_unregister_device() then kfree(zr->video_dev). With no open fds, v4l2_device_release() already kfree's via zoran_vdev_release, so the second kfree is a deterministic double-free. With an fd held, the extra kfree is a deterministic UAF. No attacker-uncontrollable race or layout is required.
- PR:LPrivileges required, low
- v4l2_open() has no capable() check; udev typically grants /dev/video* to the video group or seated uaccess user on capture/surveillance hosts (e.g. AverMedia 6 Eyes). Per CNA driver-removal UAF precedent, an unprivileged local user can hold the node and spray the freed video_device while teardown proceeds; init-namespace root is not required.
- UI:NUser interaction, none
- No victim action such as mounting a filesystem is required; the attacker opens /dev/video themselves and coordinates with driver removal (unbind/rmmod/maintenance). CNA driver-removal UAFs score UI:N.
- S:UScope, unchanged
- The double-free/UAF corrupts the host kernel slab object struct video_device. Any privilege escalation remains in the same kernel; this is not a VM/IOMMU boundary bypass.
- C:HConfidentiality impact, high
- Double-free/UAF of struct video_device lets an attacker reclaim the slab object and read leftover kernel pointers/object state via subsequent ioctl/mmap on a still-open /dev/video fd, so confidentiality is High.
- I:HIntegrity impact, high
- struct video_device embeds fops, ioctl_ops, and a release callback; reclaiming the freed object enables function-pointer overwrite and control-flow hijacking, so integrity is High.
- A:HAvailability impact, high
- A kernel double-free of video_device causes an oops/panic on the second kfree or on use of the dangling device, so availability is High.