CVE-2022-49556 KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak

What is CVE-2022-49556?

CVE-2022-49556 is a high-severity vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak

For some sev ioctl interfaces, the length parameter that is passed maybe less than or equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data that PSP firmware returns. In this case, kmalloc will allocate memory that is the size of the input rather than the size of the data. Since PSP firmware doesn't fully overwrite the allocated buffer, these sev ioctl interface may return uninitialized kernel slab memory.

Which versions are affected by CVE-2022-49556?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-49556?

Apply the vendor's patch.

Is CVE-2022-49556 being exploited?

There is no known exploitation of CVE-2022-49556 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2022-49556, GHSA-78rg-cj9j-75rj, UBUNTU-CVE-2022-49556.