Answer in brief
CVE-2021-47646 records a High severity (CVSS 7.8) vulnerability in Revert "Revert "block, bfq: honor already-setup queue merges"". The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=aee69d78dec0ffdf82e35d57c626e80dddc314d5 <f990f0985eda59d4f29fc83fcf300c92b1225d39 || >=aee69d78dec0ffdf82e35d57c626e80dddc314d5 <931aff627469a75c77b9fd3823146d0575afffd6 || >=aee69d78dec0ffdf82e35d57c626e80dddc314d5 <cc051f497eac9d8a0d816cd4bffa3415f2724871 || >=aee69d78dec0ffdf82e35d57c626e80dddc314d5 <65d8a737452e88f251fe5d925371de6d606df613 || >=aee69d78dec0ffdf82e35d57c626e80dddc314d5 <abc2129e646af7b43025d90a071f83043f1ae76c || >=aee69d78dec0ffdf82e35d57c626e80dddc314d5 <4083925bd6dc89216d156474a8076feec904e607 || >=aee69d78dec0ffdf82e35d57c626e80dddc314d5 <15729ff8143f8135b03988a100a19e66d7cb7ecd | f990f0985eda59d4f29fc83fcf300c92b1225d39, 931aff627469a75c77b9fd3823146d0575afffd6, cc051f497eac9d8a0d816cd4bffa3415f2724871, 65d8a737452e88f251fe5d925371de6d606df613, abc2129e646af7b43025d90a071f83043f1ae76c, 4083925bd6dc89216d156474a8076feec904e607, 15729ff8143f8135b03988a100a19e66d7cb7ecd |
| Linux/Linuxgeneric | 4.12 | Not reported |
| Linux/Linuxgeneric | >=430a67f9d6169a7b3e328bceb2ef9542e4153c7c <65d8a737452e88f251fe5d925371de6d606df613 || >=430a67f9d6169a7b3e328bceb2ef9542e4153c7c <abc2129e646af7b43025d90a071f83043f1ae76c || >=430a67f9d6169a7b3e328bceb2ef9542e4153c7c <4083925bd6dc89216d156474a8076feec904e607 || >=430a67f9d6169a7b3e328bceb2ef9542e4153c7c <15729ff8143f8135b03988a100a19e66d7cb7ecd | 65d8a737452e88f251fe5d925371de6d606df613, abc2129e646af7b43025d90a071f83043f1ae76c, 4083925bd6dc89216d156474a8076feec904e607, 15729ff8143f8135b03988a100a19e66d7cb7ecd |
| Linux/Linuxgeneric | 5.13 | Not reported |
Published upstream
Feb 26, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: Revert "Revert "block, bfq: honor already-setup queue merges"" A crash [1] happened to be triggered in conjunction with commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges"). The latter was then reverted by commit ebc69e897e17 ("Revert "block, bfq: honor already-setup queue merges""). Yet, the reverted commit was not the one introducing the bug. In fact, it actually triggered a UAF introduced by a different commit, and now fixed by commit d29bd41428cf ("block, bfq: reset last_bfqq_created on group change"). So, there is no point in keeping commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges") out. This commit restores it. [1] https://bugzilla.kernel.org/show_bug.cgi?id=214503
Quoted source text, attributed separately from HOL analysis.