CVE-2025-38445 md/raid1: Fix stack memory use after return in raid1_reshape
A use-after-free vulnerability in the Linux kernel RAID1 subsystem allows attackers to cause a kernel panic via stack memory access.
- 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-2025-38445?
CVE-2025-38445 is a high-severity use after free 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:
md/raid1: Fix stack memory use after return in raid1_reshape
In the raid1_reshape function, newpool is allocated on the stack and assigned to conf->r1bio_pool. This results in conf->r1bio_pool.wait.head pointing to a stack address. Accessing this address later can lead to a kernel panic.
Example access path:
raid1_reshape() { // newpool is on the stack mempool_t newpool, oldpool; // initialize newpool.wait.head to stack address mempool_init(&newpool, ...); conf->r1bio_pool = newpool; }
raid1_read_request() or raid1_write_request() { alloc_r1bio() { mempool_alloc() { // if pool->alloc fails remove_element() { --pool->curr_nr; } } } }
mempool_free() { if (pool->curr_nr < pool->min_nr) { // pool->wait.head is a stack address // wake_up() will try to access this invalid address // which leads to a kernel panic return; wake_up(&pool->wait); } }
Fix: reinit conf->r1bio_pool.wait after assigning newpool.
Weakness: CWE-125
Which versions are affected by CVE-2025-38445?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38445?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-38445 being exploited?
There is no known exploitation of CVE-2025-38445 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-65747, AZL-72929, BELL-CVE-2025-38445, DEBIAN-CVE-2025-38445, GHSA-hw4p-m7j2-x55f, ROOT-OS-DEBIAN-11-CVE-2025-38445 and 4 more.