In the Linux kernel, the following vulnerability has been resolved:

io_uring: fix link timeout refs

WARNING: CPU: 0 PID: 10242 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28
RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
io_put_req fs/io_uring.c:2140 [inline]
io_queue_linked_timeout fs/io_uring.c:6300 [inline]
__io_queue_sqe+0xbef/0xec0 fs/io_uring.c:6354
io_submit_sqe fs/io_uring.c:6534 [inline]
io_submit_sqes+0x2bbd/0x7c50 fs/io_uring.c:6660
__do_sys_io_uring_enter fs/io_uring.c:9240 [inline]
__se_sys_io_uring_enter+0x256/0x1d60 fs/io_uring.c:9182

io_link_timeout_fn() should put only one reference of the linked timeout
request, however in case of racing with the master request's completion
first io_req_complete() puts one and then io_put_req_deferred() is
called.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00019.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
1c20e9040f49687ba2ccc2ffd4411351a6c2ebff affected < 0b2a990e5d2f76d020cb840c456e6ec5f0c27530
1c20e9040f49687ba2ccc2ffd4411351a6c2ebff affected < 6f5d7a45f58d3abe3a936de1441b8d6318f978ff
9ae1f8dd372e0e4c020b345cf9e09f519265e981 affected < 876808dba2ff7509bdd7f230c4f374a0caf4f410
9ae1f8dd372e0e4c020b345cf9e09f519265e981 affected < ff4a96ba5c8f9b266706280ff8021d2ef3f17e86
9ae1f8dd372e0e4c020b345cf9e09f519265e981 affected < a298232ee6b9a1d5d732aa497ff8be0d45b5bd82
567c81912cec641db75ac6cb64c63f8367c97d19 affected —
Linux Linux affected
Version Status Constraints
5.12 affected —
0 unaffected < 5.12
5.10.43 unaffected ≤ 5.10.*
5.10.55 unaffected ≤ 5.10.*
5.12.10 unaffected ≤ 5.12.*
5.12.19 unaffected ≤ 5.12.*
5.13 unaffected ≤ *

Configuration 1 [-]

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*

No data.

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/0b2a990e5d2f76d020cb840c456e6ec5f0c27530 cve-icon cve-icon
https://git.kernel.org/stable/c/6f5d7a45f58d3abe3a936de1441b8d6318f978ff cve-icon cve-icon
https://git.kernel.org/stable/c/876808dba2ff7509bdd7f230c4f374a0caf4f410 cve-icon cve-icon
https://git.kernel.org/stable/c/a298232ee6b9a1d5d732aa497ff8be0d45b5bd82 cve-icon cve-icon
https://git.kernel.org/stable/c/ff4a96ba5c8f9b266706280ff8021d2ef3f17e86 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2024031511-CVE-2021-47124-42c9@gregkh/T/#u cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2021-47124 cve-icon
https://www.cve.org/CVERecord?id=CVE-2021-47124 cve-icon
History

Sun, 04 May 2025 13:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 13 Mar 2025 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 0.0, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N'}

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T12:41:06.098Z

Reserved: 2024-03-04T18:12:48.839Z

Link: CVE-2021-47124

cve-icon Vulnrichment

Updated: 2024-08-04T05:24:39.807Z

cve-icon NVD

Status : Analyzed

Published: 2024-03-15T21:15:07.260

Modified: 2025-03-13T19:35:51.843

Link: CVE-2021-47124

cve-icon Redhat

Severity : Low

Publid Date: 2024-03-15T00:00:00Z

Links: CVE-2021-47124 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses