CVE-2024-26753

What it actually does

Stack-based buffer overflow caused by memcpy of a larger struct (virtio_crypto_op_ctrl_req::u) into a smaller stack variable (virtio_crypto_akcipher_session_para) in the virtio crypto akcipher driver.

Why it matters to the business

Kernel crashes, potential local privilege escalation, or denial of service on Linux systems using virtio-crypto acceleration; widespread impact due to kernel prevalence across servers, cloud instances, and embedded devices.

How an attack unfolds

An attacker with the ability to trigger akcipher session setup via the virtio-crypto interface supplies a control request that causes the oversized memcpy, overwriting adjacent stack frames and potentially leading to control-flow hijacking.

How to fix it

Upgrade the Linux kernel to a fixed version such as 5.10.212 or apply commit 37077ed16c7793e21b005979d33f8a61565b7e86 (or later) from the stable tree; rebuild and reboot affected systems.

How to confirm the fix worked

Verify the running kernel version is at or above the listed fixed releases; inspect the source of virtio_crypto_akcipher_algs.c to confirm the memcpy size check or corrected buffer usage is present; recompile with the same Clang configuration to ensure the warning is resolved.

Typical attack path

1. Identify a system exposing or using a virtio-crypto device
2. Craft and submit a virtio_crypto_op_ctrl_req with akcipher session parameters sized to exceed the target stack buffer
3. Trigger the vulnerable memcpy path in virtio_crypto_akcipher_algs.c during session initialization
4. Leverage the resulting stack corruption for code execution or crash

How to detect it

Review kernel logs (dmesg, syslog) for stack overflow or out-of-bounds write warnings from virtio_crypto_akcipher_algs; look for unusual akcipher session creation failures or crashes around the virtio crypto driver after crypto operations.

What your security team should do

• Prioritize kernel upgrades on all systems using virtio-crypto drivers
• Monitor for kernel oops or stack trace reports referencing virtio_crypto_akcipher
• Restrict untrusted access to crypto accelerator devices until patched
• Apply updates within standard maintenance windows given low EPSS and no KEV listing