Lucene search

K
redhatcveRedhat.comRH:CVE-2021-47412
HistoryMay 22, 2024 - 8:59 a.m.

CVE-2021-47412

2024-05-2208:59:12
redhat.com
access.redhat.com
2
linux kernel
vulnerability
rq_qos_ops
done_bio
untracked bios
mitigation

6.4 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

9.0%

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.

6.4 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

9.0%