CVE-2026-90186

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the null blk driver where resizing submit queues or poll queues via configfs on a device with shared tags enabled can lead to a kernel crash. When a shared tag set is used, the driver falls back to module-wide queues. Shrinking the number of hardware queues via blk mq update nr hw queues() results in the nulling of excess hardware context slots. However, null map queues() continues to map CPUs to these now-NULL slots. Subsequently, blk mq map swqueue() dereferences a NULL hardware context pointer (hctx->cpumask), causing a null-pointer dereference and crashing the system.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.