Look up another CVE · open CVE-2026-64485 in the interactive tracker
CVE-2026-64485
ALSA: compress: Fix task creation error unwind
Published 2026-07-25 (3 months ago) by the Linux kernel CNA. Subsystem sound/core. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-64485 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 | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.1.4-1 | Update the kernel and reboot. Fixed in 7.1.4-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.4-1 | Update the kernel and reboot. Fixed in 7.1.4-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
snd_compr_task_new() allocates the driver task before validating the returned DMA buffers and reserving file descriptors. When either of those later steps fails, the core frees its task wrapper and DMA-buffer references without calling the driver's task_free() callback. Any driver resources allocated by task_create() are therefore leaked. The dual-fd allocation path also jumps to cleanup without storing the negative get_unused_fd_flags() result in retval. Since retval still contains the successful task_create() return value, TASK_CREATE can incorrectly report success although the task was discarded. Preserve the fd allocation errors and call task_free() when failure occurs after a successful task_create() callback.
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.
sound/core/compress_offload.c
- What this is
- SOUND - COMPRESSED AUDIOMAINTAINERS section matched on sound/core/compress_offload.c · linux-sound@vger.kernel.org · Supported
- Kernel module
- snd_compress
Check it on the machine
grep -wE 'CONFIG_SND|CONFIG_SND_COMPRESS_OFFLOAD' /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.
lsmod | grep -w snd_compressPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/arm64, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_SND, CONFIG_SND_COMPRESS_OFFLOAD
- Reads as
- all on means the file is compiled; any one off means it is not.
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
- 2026-07-25 (3 months 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 6.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- sound/core
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.13 | 6.18.39 | b27a75d42044 |
| 6.13 | 7.1.4 | 426a9947a38d |
| 6.13 | 7.2 | 4a60127debb9 |
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 vulnerable path requires opening the local ALSA compress accelerator device and issuing SET_PARAMS and TASK_CREATE ioctls; no network or physical-input path reaches it.
- AC:LAttack complexity, low
- The attacker can deterministically exhaust its own file-descriptor table so descriptor allocation fails after task_create succeeds. No race or condition outside the attacker’s control is required.
- PR:LPrivileges required, low
- There are no capable(), ns_capable(), or authentication checks in this path, so an unprivileged user with ordinary access to the ASRC device node can trigger it.
- UI:NUser interaction, none
- The attacker alone can configure the stream, exhaust descriptors, issue TASK_CREATE, and close the stream. No separate victim action is required.
- S:UScope, unchanged
- The vulnerable ALSA driver and the affected kernel resources share the same security authority; kernel compromise is a conventional local privilege escalation.
- C:HConfidentiality impact, high
- Skipping task_free leaves asrc->pair[] referencing a driver object that stream close subsequently frees, producing an attacker-reclaimable UAF in interrupt and power-management paths. Reclaimed DMA-channel pointers can influence kernel control flow and expose arbitrary kernel data.
- I:HIntegrity impact, high
- The stale pair is used for writes through completion handling and for an indirect device_terminate_all call through its DMA-channel pointer. Heap reclamation can therefore provide memory-corruption and control-flow-hijacking primitives.
- A:HAvailability impact, high
- The leak exhausts the finite ASRC contexts and exclusive DMA channels, persistently disabling the device. Dereferencing the stale pair during interrupt or suspend/resume handling can also cause a kernel oops, panic, or hang.