CVE-2024-38543 lib/test_hmm.c: handle src_pfns and dst_pfns allocation failure
A null pointer dereference in the Linux kernel's HMM test module can cause a system crash when memory allocation fails during device eviction.
- 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-2024-38543?
CVE-2024-38543 is a medium-severity vulnerability in Linux kernel, published on 19 Jun 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:
lib/test_hmm.c: handle src_pfns and dst_pfns allocation failure
The kcalloc() in dmirror_device_evict_chunk() will return null if the physical memory has run out. As a result, if src_pfns or dst_pfns is dereferenced, the null pointer dereference bug will happen.
Moreover, the device is going away. If the kcalloc() fails, the pages mapping a chunk could not be evicted. So add a __GFP_NOFAIL flag in kcalloc().
Finally, as there is no need to have physically contiguous memory, Switch kcalloc() to kvcalloc() in order to avoid failing allocations.
Weakness: CWE-476
Which versions are affected by CVE-2024-38543?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-38543?
Apply the vendor's patch.
Is CVE-2024-38543 being exploited?
There is no known exploitation of CVE-2024-38543 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-48310, BELL-CVE-2024-38543, DEBIAN-CVE-2024-38543, GHSA-3q6x-gxwh-88p9, ROOT-OS-DEBIAN-11-CVE-2024-38543, ROOT-OS-UBUNTU-2204-CVE-2024-38543 and 1 more.