CVE-2025-38445

/// Technical 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.wa

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References