CVE-2025-38445: md/raid1: Fix stack memory use after return in raid1_reshape

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-25 · updated 2026-06-17
Weakness: CWE-125

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.

Affected products

Debian Linux: 11.0
Linux kernel: from 4.18 before 5.4.296; from 5.5 before 5.10.240; from 5.11 before 5.15.189; from 5.16 before 6.1.146; from 6.2 before 6.6.99; from 6.7 before 6.12.39 — fixed in 5.10.240, 5.15.189, 5.4.296, 6.1.146, 6.12.39, 6.15.7

How to fix

Upgrade to a fixed version: Linux kernel 5.10.240, 5.15.189, 5.4.296, 6.1.146. Check the vendor advisory for mitigations.

References

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