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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2024-39508
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2024-07-12 13:15:13 UTC
Updated2026-08-04 11:19:02 UTC
DescriptionIn 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.

Risk And Classification

Primary CVSS: v3.1 4.7 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-362

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary4.7MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 2b188cc1bb857a9d4701ae59aa7768b5124e262e ab702c3483db9046bab9f40306f1a28b22dbbdc0 git Not specified
CNA Linux Linux affected 2b188cc1bb857a9d4701ae59aa7768b5124e262e 1cbb0affb15470a9621267fe0a8568007553a4bf git Not specified
CNA Linux Linux affected 2b188cc1bb857a9d4701ae59aa7768b5124e262e 8a565304927fbd28c9f028c492b5c1714002cbab git Not specified
CNA Linux Linux affected 5.1 Not specified
CNA Linux Linux unaffected 5.1 semver Not specified
CNA Linux Linux unaffected 6.6.35 6.6.* semver Not specified
CNA Linux Linux unaffected 6.9.6 6.9.* semver Not specified
CNA Linux Linux unaffected 6.10 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/8a565304927fbd28c9f028c492b5c1714002cbab af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/1cbb0affb15470a9621267fe0a8568007553a4bf af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/ab702c3483db9046bab9f40306f1a28b22dbbdc0 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
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