CVE-2026-64304VulnerabilityPublished 07/25/2026

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - validate RSA CRT component lengths The generic RSA key parser… (CVE-2026-64304)

Source GCVE Database

Severity

High

No CVSS score published yet

Exploitation: Not in CISA KEV, no exploitation reported
EPSS: 0.2% chance of exploitation in 30 days – higher than 5% of CVEs

What to do

AI-suggested

A fix has been implemented in the Linux kernel to add length checks for RSA CRT components in the crypto qat driver, preventing out-of-bounds writes. Users should update their Linux kernel to a version that includes this patch. Since this is a kernel-level vulnerability, applying the official kernel update is the recommended remediation. Patch status is not explicitly stated here; check the Linux kernel vendor advisory or source repository for the exact fixed version.

Description

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - validate RSA CRT component lengths 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.

Summary

The Linux kernel's crypto qat driver had a vulnerability (CVE-2026-64304) where the RSA CRT components (p, q, dp, dq, qinv) could be larger than the half-size DMA buffers allocated by qat_rsa_setkey_crt(). The existing generic RSA key parser bounds each CRT component by the modulus size, but the qat driver copies these components into half-size buffers without verifying if the component length exceeds half the key size. This leads to an underflow in the memcpy offset calculation and causes memory corruption by writing out of bounds. The patch adds explicit length checks for each CRT component to ensure they do not exceed half the key size, causing the driver to revert to a non-CRT code path instead of corrupting memory.

Impact

This vulnerability can cause memory corruption in the kernel crypto qat driver when processing RSA keys with CRT components larger than expected. Memory corruption in kernel space can lead to system instability, crashes, or potentially privilege escalation if exploited. However, no known exploits are reported in the wild.

What to do

Description

AnalysisAI-generated, updated 07/25/2026, 23:37:44 UTC

Technical details

References

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