TLDRVuln - Cybersecurity Vulnerabilities Made Simple

In the Linux kernel, the following vulnerability has been resolved:

blk-mq: don't touch ->tagset in blk_mq_get_sq_hctx

blk_mq_run_hw_queues() could be run when there isn't queued request and

after queue is cleaned up, at that time tagset is freed, because tagset

lifetime is covered by driver, and often freed after blk_cleanup_queue()

returns.

So don't touch ->tagset for figuring out current default hctx by the mapping

built in request queue, so use-after-free on tagset can be avoided. Meantime

this way should be fast than retrieving mapping from tagset.