CVE-2025-38364 maple_tree: fix MA_STATE_PREALLOC flag in mas_preallocate()
A null pointer dereference in the Linux kernel maple tree implementation can cause a system crash when specific memory allocation conditions are met.
- 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-2025-38364?
CVE-2025-38364 is a medium-severity vulnerability in Debian Debian Linux, published on 25 Jul 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:
maple_tree: fix MA_STATE_PREALLOC flag in mas_preallocate()
Temporarily clear the preallocation flag when explicitly requesting allocations. Pre-existing allocations are already counted against the request through mas_node_count_gfp(), but the allocations will not happen if the MA_STATE_PREALLOC flag is set. This flag is meant to avoid re-allocating in bulk allocation mode, and to detect issues with preallocation calculations.
The MA_STATE_PREALLOC flag should also always be set on zero allocations so that detection of underflow allocations will print a WARN_ON() during consumption.
User visible effect of this flaw is a WARN_ON() followed by a null pointer dereference when subsequent requests for larger number of nodes is ignored, such as the vma merge retry in mmap_region() caused by drivers altering the vma flags (which happens in v6.6, at least)
Weakness: CWE-476
Which versions are affected by CVE-2025-38364?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38364?
Apply the vendor's patch.
Is CVE-2025-38364 being exploited?
There is no known exploitation of CVE-2025-38364 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-65792, BELL-CVE-2025-38364, DEBIAN-CVE-2025-38364, GHSA-p347-69w9-6826, ROOT-OS-DEBIAN-12-CVE-2025-38364, ROOT-OS-UBUNTU-2404-CVE-2025-38364 and 1 more.