CVE-2024-57945 riscv: mm: Fix the out of bound issue of vmemmap address
A memory corruption vulnerability in the Linux kernel's RISC-V memory management allows attackers to potentially execute arbitrary code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-57945?
CVE-2024-57945 is a high-severity memory corruption vulnerability in Linux kernel, published on 21 Jan 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:
riscv: mm: Fix the out of bound issue of vmemmap address
In sparse vmemmap model, the virtual address of vmemmap is calculated as: ((struct page *)VMEMMAP_START - (phys_ram_base >> PAGE_SHIFT)). And the struct page's va can be calculated with an offset: (vmemmap + (pfn)).
However, when initializing struct pages, kernel actually starts from the first page from the same section that phys_ram_base belongs to. If the first page's physical address is not (phys_ram_base >> PAGE_SHIFT), then we get an va below VMEMMAP_START when calculating va for it's struct page.
For example, if phys_ram_base starts from 0x82000000 with pfn 0x82000, the first page in the same section is actually pfn 0x80000. During init_unavailable_range(), we will initialize struct page for pfn 0x80000 with virtual address ((struct page *)VMEMMAP_START - 0x2000), which is below VMEMMAP_START as well as PCI_IO_END.
This commit fixes this bug by introducing a new variable 'vmemmap_start_pfn' which is aligned with memory section size and using it to calculate vmemmap address instead of phys_ram_base.
Weakness: CWE-125
Which versions are affected by CVE-2024-57945?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-57945?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2024-57945 being exploited?
There is no known exploitation of CVE-2024-57945 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-67845, BELL-CVE-2024-57945, DEBIAN-CVE-2024-57945, GHSA-743f-m6p2-83h6, ROOT-OS-DEBIAN-11-CVE-2024-57945, ROOT-OS-DEBIAN-12-CVE-2024-57945 and 2 more.