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CVE-2026-93039
ASoC: meson: Keep link pointers valid on realloc failure
Published 2026-09-17 (31 days ago) by the Linux kernel CNA. Subsystem sound/soc. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-93039 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
meson_card_reallocate_links() grows the DAI link and private data arrays with two consecutive krealloc() calls and updates the owner pointers only after both calls have succeeded. A successful krealloc() may move the data: it frees the old block and returns a new one. When that happens for the link array and the second krealloc() then fails, card->dai_link still points to the block that krealloc() already freed, and the error path frees the new block too. The probe error path then calls meson_card_clean_references(), which dereferences card->dai_link and kfree()s it again, resulting in a use-after-free and a double free. Commit card->dai_link and card->num_links right after the first krealloc() succeeds, so the pointer always refers to a valid allocation that meson_card_clean_references() can walk and free. krealloc() with __GFP_ZERO zero-initializes the added entries, so walking them on the error path is safe. With both failure paths reduced to a plain return, drop the goto labels and the error message.
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/meson/meson-card-utils.c
- What this is
- ARM/Amlogic Meson SoC Sound DriversMAINTAINERS section matched on sound/soc/meson/ · linux-sound@vger.kernel.org · Maintained
- Kernel module
- snd_soc_meson_card_utils
Check it on the machine
grep -wE 'CONFIG_SND|CONFIG_SND_MESON_CARD_UTILS|CONFIG_SND_SOC' /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_soc_meson_card_utilsPrints 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/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-arm64, i386/686, i386/686-pae, i386/rt/686-pae, ppc64el/powerpc64le
- trixieMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-arm64, armel/rpi, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- forky, sidMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, arm64/cloud-arm64, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-arm64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_SND, CONFIG_SND_MESON_CARD_UTILS, CONFIG_SND_SOC
- 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
- 2026-09-17 (31 days ago)source
- CVSS
- 7.4 high
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.16%, higher than 4.4% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- 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 |
|---|---|---|
| 4.19 | 5.10.270 | de33afc57f24 |
| 4.19 | 5.15.221 | 1c1485343b7c |
| 4.19 | 6.1.188 | 8db0a0fc84e8 |
| 4.19 | 6.6.157 | 41e92e0caa1f |
| 4.19 | 6.12.110 | 0b30fbe6bf7c |
| 4.19 | 6.18.52 | 8fec16898f18 |
| 4.19 | 7.2.6 | 5ed1b048527b |
| 4.19 | 7.3 | 2aaa41cf974f |
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
- meson_card_reallocate_links() is reached only from meson_card_probe() (axg_card_pdrv.probe for compatible "amlogic,axg-sound-card") via meson_card_add_links() and axg_card_add_tdm_loopback(); no network protocol message or USB descriptor carries the dangling dai_link pointer.
- AC:HAttack complexity, high
- The UAF fires only if meson_card_reallocate_links()'s krealloc of card->dai_link succeeds and the following krealloc of priv->link_data returns NULL. Both are GFP_KERNEL (reclaim allowed). meson_card_probe() then returns -ENOMEM; snd_soc_bind_card() maps DAI-component -EPROBE_DEFER to 0, so driver core does not retry axg_card_add_tdm_loopback().
- PR:NPrivileges required, none
- meson_card_probe() and axg_card_add_tdm_loopback() have no capable() check. On Amlogic boards whose DT includes amlogic,axg-sound-card with a TDM playback link (meson-axg-s400.dts dai-link-6 / meson-khadas-vim3.dtsi dai-link-6), of_platform or udev autoload of snd-soc-meson-axg-sound-card runs this probe without an OS account.
- UI:NUser interaction, none
- axg_card_add_tdm_loopback() runs inside meson_card_probe() during automatic platform bind of the DT sound node; no victim must open /dev/snd/*, mount media, or plug extra hardware.
- S:UScope, unchanged
- meson_card_clean_references() use-after-frees and double-frees the host-kernel card->dai_link array from meson_card_reallocate_links(); impact stays in this kernel and is not a VM escape or IOMMU/DMA bypass.
- C:HConfidentiality impact, high
- On the second-krealloc failure, meson_card_clean_references() walks the stale card->dai_link with for_each_card_prelinks() and reads link->cpus and link->codecs from the already-freed snd_soc_dai_link array, a heap UAF read.
- I:HIntegrity impact, high
- The same path kfree()s card->dai_link again (the old block krealloc may already have freed, or err_ldata's kfree(links) already released) and of_node_put()s pointers loaded from that freed array, a double-free/UAF write primitive.
- A:HAvailability impact, high
- meson_card_clean_references() dereferences and kfree()s the freed dai_link array after meson_card_reallocate_links() returns -ENOMEM, causing a kernel oops or panic (slab UAF / invalid-free).