Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Linux Linux — block: don't call rq_qos_ops->done_bio if the bio isn't tracked
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0023 14.3 —
AFFECTED
Product Versions Fixed
Linux 67b42d0bf7a8fd1ec0cf1acdc9550e688d7c8578 – —
Linux 4.19 – 5.10.241
TIMELINE
May 21 Reserved by Linux
May 21 Published (CNA: Linux)
Aug 4 RESCORED — CVE-2021-47412 (Linux). CVSS 7.8 → 5.5 (NVD).
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.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| May 21, 2024 | Reserved | Reserved by Linux |
| May 21, 2024 | Published | Published (CNA: Linux) |
| August 4, 2026 | RESCORED | RESCORED — CVE-2021-47412 (Linux). CVSS 7.8 → 5.5 (NVD). |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | 67b42d0bf7a8fd1ec0cf1acdc9550e688d7c8578 | — |
| Linux | Linux | — | 4.19 | 5.10.241 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-47412 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.