7.8

CVE-2024-39508: io_uring/io-wq: Use set_bit() and test_bit() at worker->flags

Modified
AliasesUBUNTU-CVE-2024-39508DEBIAN-CVE-2024-39508
Published 12-07-2024Last modified 05-08-2026

Vulnerability summary

CVE-2024-39508 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.8% 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
0.22%
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

Advisory lineage

Upstream 0 · Downstream 16 · Related 15
RHSA-2024:9315SUSE-SU-2024:2894-1SUSE-SU-2024:2939-1SUSE-SU-2024:2947-1SUSE-SU-2024:3194-1SUSE-SU-2024:3195-1

Timeline

  1. 12-07-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/io-wq: Use set_bit() and test_bit() at worker->flags Utilize set_bit() and test_bit() on worker->flags within io_uring/io-wq to address potential data races. The structure io_worker->flags may be accessed through various data paths, leading to concurrency issues. When KCSAN is enabled, it reveals data races occurring in io_worker_handle_work and io_wq_activate_free_worker functions. BUG: KCSAN: data-race in io_worker_handle_work / io_wq_activate_free_worker write to 0xffff8885c4246404 of 4 bytes by task 49071 on cpu 28: io_worker_handle_work (io_uring/io-wq.c:434 io_uring/io-wq.c:569) io_wq_worker (io_uring/io-wq.c:?) <snip> read to 0xffff8885c4246404 of 4 bytes by task 49024 on cpu 5: io_wq_activate_free_worker (io_uring/io-wq.c:? io_uring/io-wq.c:285) io_wq_enqueue (io_uring/io-wq.c:947) io_queue_iowq (io_uring/io_uring.c:524) io_req_task_submit (io_uring/io_uring.c:1511) io_handle_tw_list (io_uring/io_uring.c:1198) <snip> Line numbers against commit 18daea77cca6 ("Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm"). These races involve writes and reads to the same memory location by different tasks running on different CPUs. To mitigate this, refactor the code to use atomic operations such as set_bit(), test_bit(), and clear_bit() instead of basic "and" and "or" operations. This ensures thread-safe manipulation of worker flags. Also, move `create_index` to avoid holes in the structure.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

13%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.22% 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

Affected systems

Version check

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

Ubuntu125 products
  • linuxAll versions (No fix recorded) | < 6.8.0-44.44
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1015.16
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 2b188cc1bb857a9d4701ae59aa7768b5124e262e, < ab702c3483db9046bab9f40306f1a28b22dbbdc0 | ≥ 2b188cc1bb857a9d4701ae59aa7768b5124e262e, < 1cbb0affb15470a9621267fe0a8568007553a4bf | ≥ 2b188cc1bb857a9d4701ae59aa7768b5124e262e, < 8a565304927fbd28c9f028c492b5c1714002cbab | 5.1
  • linux_kernel≥ 5.1, < 6.6.35 | ≥ 6.7, < 6.9.6
Debian1 product
  • linuxAll versions (No fix recorded) | < 6.9.7-1

3 vendors · 128 products

References

14 links
Show all 14 references