CVE-2021-47123

io_uring: fix ltout double free on completion race

HIGH
7.8
CVSS Score
Published: March 15, 2024 at 08:14 PM UTC
Updated: August 5, 2026 at 09:24 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring: fix ltout double free on completion race Always remove linked timeout on io_link_timeout_fn() from the master request link list, otherwise we may get use-after-free when first io_link_timeout_fn() puts linked timeout in the fail path, and then will be found and put on master's free.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.11 ≤ v < 5.12.105.11 ≤ v < 5.135.13 rc190cd7e424969d29aff653333b4dcb4e2e199d791
Vendor states this is fixed in 1f64f5e903b9d1d157875721e02adadc9d6f0a5d (fixed)
Vendor states this is fixed in 447c19f3b5074409c794b350b10306e1da1ef4ba (fixed)
Vendor states this is fixed in 5.11 (unaffected)
Vendor states this is fixed in 5.12.10 (unaffected)
Vendor states this is fixed in 5.13 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/1f64f5e903b9d1d157875721e02adadc9d6f0a5d
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/447c19f3b5074409c794b350b10306e1da1ef4ba

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-415CWE-416

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