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TI-2021-22283 Aliases CVE-2021-47646GHSA-8qgg-vj9j-hh4r

Revert "Revert "block, bfq: honor already-setup queue merges""

Priority LOW 36CWE-416Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 3 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00284 21st percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.15.33, 5.16.19, 5.17.2 +1Red Hat: 1 advisoryRed Hat: 3 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.13 and later5.15.33, 5.16.19, 5.17.2, 5.18Patch availableCNA
  • Linux VendorLinux Affected 5.13 and later Fixed in 5.15.33, 5.16.19, 5.17.2, 5.18 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*before 4.19.238; 4.20 to before 5.4.189; 5.5 to before 5.10.110; 5.11 to before 5.15.33; 5.16 to before 5.16.19; 5.17 to before 5.17.2VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.19.238; 4.20 to before 5.4.189; 5.5 to before 5.10.110; 5.11 to before 5.15.33; 5.16 to before 5.16.19; 5.17 to before 5.17.2 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.15.33, 5.16.19, 5.17.2, 5.18

Red Hat 1 advisory

  • RHSA-2022:8267 Released 2022-11-15 · Red Hat rating Moderate
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-162.6.1.el9_1
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-debug-devel-5.14.0-162.6.1.el9_1, kernel-debug-devel-matched-5.14.0-162.6.1.el9_1, kernel-devel-5.14.0-162.6.1.el9_1 +5
    • Red Hat Enterprise Linux BaseOS (v. 9) bpftool-5.14.0-162.6.1.el9_1, kernel-5.14.0-162.6.1.el9_1, kernel-abi-stablelists-5.14.0-162.6.1.el9_1 +14

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 8AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat CodeReady Linux Builder (v. 9)Fixed RHSA-2022:8267
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2022:8267
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2022:8267
Not affected: 3 products
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-47646
  2. 2026-10-03 Alias added: GHSA-8qgg-vj9j-hh4r

References

Patch 4

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences