CVE-2022-49004 riscv: Sync efi page table's kernel mappings before switching

What is CVE-2022-49004?

CVE-2022-49004 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 Oct 2024. 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:

riscv: Sync efi page table's kernel mappings before switching

The EFI page table is initially created as a copy of the kernel page table. With VMAP_STACK enabled, kernel stacks are allocated in the vmalloc area: if the stack is allocated in a new PGD (one that was not present at the moment of the efi page table creation or not synced in a previous vmalloc fault), the kernel will take a trap when switching to the efi page table when the vmalloc kernel stack is accessed, resulting in a kernel panic.

Fix that by updating the efi kernel mappings before switching to the efi page table.

Which versions are affected by CVE-2022-49004?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-49004?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2022-49004 being exploited?

There is no known exploitation of CVE-2022-49004 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-2022-49004, GHSA-f43m-69ch-cggg, ROOT-OS-DEBIAN-11-CVE-2022-49004, UBUNTU-CVE-2022-49004.