CVE-2024-39508

MEDIUM EPSS 9.8%
Published Jul 12, 20241y ago · Modified Jun 17, 20261w ago
4.7 CVSS 3.1
Medium
Find Similar
Published Jul 12, 2024 1y ago
Last Modified Jun 17, 2026 1w ago

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 Details

Base Score
4.7
Exploitability
1.0
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity High
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
9.8% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-362

Affected Products 2

VendorProductVersionRange
linuxlinux_kernel*≥5.1  –  <6.6.35
linuxlinux_kernel*≥6.7  –  <6.9.6

References 3

  • git.kernel.org https://git.kernel.org/stable/c/1cbb0affb15470a9621267fe0a8568007553a4bf
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8a565304927fbd28c9f028c492b5c1714002cbab
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ab702c3483db9046bab9f40306f1a28b22dbbdc0
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/1cbb0affb15470a9621267fe0a8568007553a4bf
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8a565304927fbd28c9f028c492b5c1714002cbab
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ab702c3483db9046bab9f40306f1a28b22dbbdc0
    Patch