发布于3月6日3月6日 Members Red Hat: CVE-2021-47412: kernel: block: don't call rq_qos_ops->done_bio if the bio isn't tracked (Multiple Advisories) Severity 4 CVSS (AV:L/AC:H/Au:S/C:N/I:N/A:C) Published 05/21/2024 Created 09/26/2024 Added 09/25/2024 Modified 09/25/2024 Description 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. Solution(s) redhat-upgrade-kernel redhat-upgrade-kernel-rt References CVE-2021-47412 RHSA-2024:7000 RHSA-2024:7001
