7.8

CVE-2021-47124: io_uring: fix link timeout refs

Modified
AliasesUBUNTU-CVE-2021-47124DEBIAN-CVE-2021-47124
Published 15-03-2024Last modified 05-08-2026

Vulnerability summary

CVE-2021-47124 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 15.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.24%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 15-03-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.24%

Chance of exploitation in the next 30 days

Percentile

16%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.24% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu62 products
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
  • linux-aws-5.13All versions (No fix recorded)
  • linux-aws-5.19All versions (No fix recorded)
Linux2 products
  • linux≥ 1c20e9040f49687ba2ccc2ffd4411351a6c2ebff, < 0b2a990e5d2f76d020cb840c456e6ec5f0c27530 | ≥ 1c20e9040f49687ba2ccc2ffd4411351a6c2ebff, < 6f5d7a45f58d3abe3a936de1441b8d6318f978ff | ≥ 9ae1f8dd372e0e4c020b345cf9e09f519265e981, < 876808dba2ff7509bdd7f230c4f374a0caf4f410 | ≥ 9ae1f8dd372e0e4c020b345cf9e09f519265e981, < ff4a96ba5c8f9b266706280ff8021d2ef3f17e86 | ≥ 9ae1f8dd372e0e4c020b345cf9e09f519265e981, < a298232ee6b9a1d5d732aa497ff8be0d45b5bd82 | 567c81912cec641db75ac6cb64c63f8367c97d19 | ≥ 5.10.26, < 5.10.43 | ≥ 5.10.26, < 5.10.55 | ≥ 5.11.6, < 5.12 | 5.12
  • linux_kernel≥ 5.10.26, < 5.10.43 | ≥ 5.10.44, < 5.10.55 | ≥ 5.12, < 5.12.10 | ≥ 5.12.11, < 5.12.19 | 5.13:rc1
Debian1 product
  • linux< 5.14.6-1

3 vendors · 65 products

References

9 links