CVE-2024-45022 mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0
A flaw in Linux kernel vmalloc allows memory corruption when high-order allocations fail, potentially enabling code execution or privilege escalation.
- 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-2024-45022?
CVE-2024-45022 is a high-severity memory corruption vulnerability in Linux kernel, published on 11 Sep 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:
mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0
The __vmap_pages_range_noflush() assumes its argument pages** contains pages with the same page shift. However, since commit e9c3cda4d86e ("mm, vmalloc: fix high order __GFP_NOFAIL allocations"), if gfp_flags includes __GFP_NOFAIL with high order in vm_area_alloc_pages() and page allocation failed for high order, the pages** may contain two different page shifts (high order and order-0). This could lead __vmap_pages_range_noflush() to perform incorrect mappings, potentially resulting in memory corruption.
Users might encounter this as follows (vmap_allow_huge = true, 2M is for PMD_SIZE):
kvmalloc(2M, __GFP_NOFAIL|GFP_X) __vmalloc_node_range_noprof(vm_flags=VM_ALLOW_HUGE_VMAP) vm_area_alloc_pages(order=9) ---> order-9 allocation failed and fallback to order-0 vmap_pages_range() vmap_pages_range_noflush() __vmap_pages_range_noflush(page_shift = 21) ----> wrong mapping happens
We can remove the fallback code because if a high-order allocation fails, __vmalloc_node_range_noprof() will retry with order-0. Therefore, it is unnecessary to fallback to order-0 here. Therefore, fix this by removing the fallback code.
Weakness: CWE-787
Which versions are affected by CVE-2024-45022?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-45022?
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-2024-45022 being exploited?
There is no known exploitation of CVE-2024-45022 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-49218, BELL-CVE-2024-45022, DEBIAN-CVE-2024-45022, GHSA-7fv4-rmp7-g4qh, UBUNTU-CVE-2024-45022.