CVE-2021-47412: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: block: don't call rq_qos_ops->done_bio if the bio isn't tracked rq_qos framework is only applied on request based driver, so: 1) rq_qos_done_bio() needn't to be called for bio based driver 2) rq_qos_done_bio() needn't to be called for bio which isn't tracked, such as bios ended from error handling code. Especially in bio_endio(): 1) request queue is referred via bio->bi_bdev->bd_disk->queue, which may be gone since request queue refcount may not be held in above two cases 2) q->rq_qos may be freed in blk_cleanup_queue() when calling into __rq_qos_done_bio() Fix the potential kernel panic by not calling rq_qos_ops->done_bio if the bio isn't tracked. This way is safe because both ioc_rqos_done_bio() and blkcg_iolatency_done_bio() are nop if the bio isn't tracked.

Affected products

• Linux Linux Kernel: before 5.10.241 (fixed in 5.10.241); from 5.11, before 5.14.11 (fixed in 5.14.11); version 5.15 only

Published 2024-05-21. Last modified 2026-08-04.