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CVE-2026-74333
ASoC: amd: acp-sdw-legacy: Bound DAI link iteration
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem sound/soc. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-74333 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 | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
create_sdw_dailinks() walks soc_dais until it finds an entry with initialised cleared, but soc_dais is allocated with exactly num_ends entries. If all entries are initialised, the loop reads past the end of the array. This was reported by KASAN: BUG: KASAN: slab-out-of-bounds in mc_probe+0x26b3/0x2774 [snd_acp_sdw_legacy_mach] Read of size 1 Pass the allocated entry count to create_sdw_dailinks() and stop before reading past the array.
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/soc/amd/acp/acp-sdw-legacy-mach.c
- What this is
- AMD ASoC DRIVERSMAINTAINERS section matched on sound/soc/amd/ · linux-sound@vger.kernel.org · Supported
- Kernel module
- snd_acp_sdw_legacy_mach
Check it on the machine
grep -wE 'CONFIG_SND|CONFIG_SND_AMD_ACP_CONFIG|CONFIG_SND_SOC|CONFIG_SND_SOC_AMD_LEGACY_SDW_MACH' /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_acp_sdw_legacy_machPrints 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. The build rule could not be established for 2 releases, so nothing is claimed about those.
- bookworm, trixie?
- forky, sidMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- ?
- not established - no Makefile entry for the affected file
- M
- a module where it is built at all; some flavours do not build it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switches
- CONFIG_SND, CONFIG_SND_AMD_ACP_CONFIG, CONFIG_SND_SOC, CONFIG_SND_SOC_AMD_LEGACY_SDW_MACH
- 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
- 2026-08-15 (2 months ago)source
- CVSS
- 8.4 high
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.19%, higher than 8.4% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- sound/soc
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.13 | 6.18.40 | 1279bdab5fa1 |
| 6.13 | 7.1.5 | 0230471eef59 |
| 6.13 | 7.2 | d49ecdf327cc |
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 flaw is only reachable during local AMD ACP PCI/platform driver probe (snd_acp63_probe -> acp63_machine_register -> mc_probe); there is no network, Bluetooth, or userspace syscall/ioctl path to create_sdw_dailinks().
- AC:LAttack complexity, low
- On affected AMD SoundWire legacy laptops, when every soc_dais slot is marked initialised the OOB read is deterministic at each boot/probe; KASAN already hit this in mc_probe on real hardware, so no attacker-controlled race or rare timing is required.
- PR:NPrivileges required, none
- Exploitation needs no credentials: mc_probe runs automatically during pre-login kernel initialization when ACPI/PCI matches an amd_sdw machine table on built-in SoundWire hardware, before any authenticated user session exists.
- UI:NUser interaction, none
- No victim interaction is required beyond normal system boot on vulnerable AMD SoundWire hardware; the bug triggers during driver initialization, not from opening audio devices or mounting filesystems.
- S:UScope, unchanged
- Impact is confined to kernel heap corruption and crash/privilege escalation within the host kernel; this is not a VM escape, IOMMU bypass, or cross-security-authority boundary.
- C:HConfidentiality impact, high
- The bug is a slab out-of-bounds read (KASAN: read of size 1) past the soc_dais array, which can disclose adjacent kernel heap objects and satisfies the guidance to rate out-of-bounds reads as High.
- I:HIntegrity impact, high
- After the OOB initialised check, the loop can treat adjacent slab memory as a valid asoc_sdw_dailink and call create_sdw_dailink(), corrupting list heads and allocation sizes and enabling further heap corruption or control-flow hijack.
- A:HAvailability impact, high
- KASAN reported slab-out-of-bounds in mc_probe during audio card registration; continued iteration over corrupt structures can kernel oops/panic at boot, denying availability to all users on the machine.