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CVE-2026-64304
crypto: qat - validate RSA CRT component lengths
Published 2026-07-25 (3 months ago) by the Linux kernel CNA. Subsystem drivers/crypto. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-64304 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-4720-1 · 2026-08-05 · text | 6.1.180-1 | Update the kernel and reboot. DLA-4720-1 shipped the fix on 2026-08-05, in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.96-1 | Update the kernel and reboot. Fixed in 6.12.96-1. A running kernel keeps the old code until the machine restarts. |
| 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. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4724-1 · 2026-08-07 · text | 6.12.100-1~deb12u1 | Update the kernel and reboot. DLA-4724-1 shipped the fix on 2026-08-07, in 6.12.100-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
The generic RSA key parser (rsa_helper.c) bounds each CRT component (p, q, dp, dq, qinv) by the modulus size n_sz, but qat_rsa_setkey_crt() allocates half-size DMA buffers (key_sz / 2) and right-aligns each component with: memcpy(dst + half_key_sz - len, src, len) When a CRT component is larger than half_key_sz the subtraction underflows and memcpy writes past the DMA buffer, causing memory corruption. Add a len > half_key_sz check next to the existing !len check for each of the five CRT components so the driver falls back to the non-CRT path instead of writing out of bounds.
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/crypto/intel/qat/qat_common/qat_asym_algs.c
- What this is
- QAT DRIVERMAINTAINERS section matched on drivers/crypto/intel/qat/ · qat-linux@intel.com · Supported
- Kernel module
- intel_qat
Check it on the machine
grep -wE 'CONFIG_CRYPTO|CONFIG_CRYPTO_DEV_QAT' /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 intel_qatPrints 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 1 release, so nothing is claimed about those.
- bookworm?
- trixieMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- 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
- bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- ?
- 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_CRYPTO, CONFIG_CRYPTO_DEV_QAT
- 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 5.8% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/crypto
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.8 | 5.10.261 | 6d99c5fadd2d |
| 4.8 | 5.15.212 | c34369473bfe |
| 4.8 | 6.1.178 | 1002719d1307 |
| 4.8 | 6.6.145 | 500319830d76 |
| 4.8 | 6.12.96 | 3d61a214fdcd |
| 4.8 | 6.18.39 | 6fb62b767f3e |
| 4.8 | 7.1.4 | ce42224487c5 |
| 4.8 | 7.2 | b3ac78756588 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4724-1 | 2026-08-07 | bookworm 6.12.100-1~deb12u1 | tracker |
| DLA-4723-1 | 2026-08-07 | bullseye 6.1.180-1~deb11u1 | tracker |
| DLA-4720-1 | 2026-08-05 | bookworm 6.1.180-1 | tracker |
| DLA-4717-1 | 2026-08-05 | bullseye 5.10.262-1 | 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
- An unprivileged local process can add a crafted PKCS#8 RSA private key to its own keyring and invoke KEYCTL_PKEY_QUERY, which selects qat-rsa and reaches the vulnerable key setup path.
- AC:LAttack complexity, low
- With an active QAT asymmetric service and PKCS#8 parser, an oversized CRT integer deterministically causes unsigned offset underflow and an out-of-bounds memcpy. No race or attacker-uncontrollable condition is required.
- PR:LPrivileges required, low
- An ordinary user can create, search, and use keys in a personal process, thread, or session keyring. No capability, administrator privilege, or user namespace is required.
- UI:NUser interaction, none
- The attacker directly performs the add_key and keyctl system calls without any victim action.
- S:UScope, unchanged
- The vulnerable QAT driver and the corrupted kernel resources share the same security authority. Ordinary kernel privilege escalation does not cross a CVSS scope boundary.
- C:HConfidentiality impact, high
- The controlled kernel-memory overwrite can corrupt page tables, credentials, or control-flow objects and plausibly yield code execution with access to protected kernel memory.
- I:HIntegrity impact, high
- Attacker-controlled CRT bytes are written outside the coherent DMA allocation, potentially through multiple CRT components. This can provide powerful kernel-memory corruption and control-flow hijacking primitives.
- A:HAvailability impact, high
- The invalid destination can cause an immediate kernel fault or corrupt unrelated kernel memory and subsequently panic or hang the system. The attack is repeatable.