Linux Kernel Array Index Out-of-Bounds Vulnerability in Block Layer

A vulnerability in the Linux kernel's block layer has been addressed, which involved improper handling of offline queues in the function blk_mq_alloc_request_hctx(). This flaw could be triggered by the test nvme/004, leading to a undefined behavior sanitization (UBSAN) error for array index out-of-bounds. The issue arose because the index exceeded the allocated range for a specific data type, causing potential memory access violations.

Impact

Exploitation of this vulnerability could lead to array index out-of-bounds errors, allowing for memory corruption or unauthorized memory access.

Reproduction

The vulnerability can be reproduced by running the NVMe test suite, specifically the test case 'nvme/004', which triggers the array index out-of-bounds error in the block layer's request handling function.