4.7
MEDIUM
CVE-2024-46704
Linux Kernel Workqueue: Data Race Vulnerability
Description

In the Linux kernel, the following vulnerability has been resolved: workqueue: Fix spruious data race in __flush_work() When flushing a work item for cancellation, __flush_work() knows that it exclusively owns the work item through its PENDING bit. 134874e2eee9 ("workqueue: Allow cancel_work_sync() and disable_work() from atomic contexts on BH work items") added a read of @work->data to determine whether to use busy wait for BH work items that are being canceled. While the read is safe when @from_cancel, @work->data was read before testing @from_cancel to simplify code structure: data = *work_data_bits(work); if (from_cancel && !WARN_ON_ONCE(data & WORK_STRUCT_PWQ) && (data & WORK_OFFQ_BH)) { While the read data was never used if !@from_cancel, this could trigger KCSAN data race detection spuriously: ================================================================== BUG: KCSAN: data-race in __flush_work / __flush_work write to 0xffff8881223aa3e8 of 8 bytes by task 3998 on cpu 0: instrument_write include/linux/instrumented.h:41 [inline] ___set_bit include/asm-generic/bitops/instrumented-non-atomic.h:28 [inline] insert_wq_barrier kernel/workqueue.c:3790 [inline] start_flush_work kernel/workqueue.c:4142 [inline] __flush_work+0x30b/0x570 kernel/workqueue.c:4178 flush_work kernel/workqueue.c:4229 [inline] ... read to 0xffff8881223aa3e8 of 8 bytes by task 50 on cpu 1: __flush_work+0x42a/0x570 kernel/workqueue.c:4188 flush_work kernel/workqueue.c:4229 [inline] flush_delayed_work+0x66/0x70 kernel/workqueue.c:4251 ... value changed: 0x0000000000400000 -> 0xffff88810006c00d Reorganize the code so that @from_cancel is tested before @work->data is accessed. The only problem is triggering KCSAN detection spuriously. This shouldn't need READ_ONCE() or other access qualifiers. No functional changes.

INFO

Published Date :

Sept. 13, 2024, 7:15 a.m.

Last Modified :

Sept. 19, 2024, 1:32 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

3.6

Exploitability Score :

1.0
Affected Products

The following products are affected by CVE-2024-46704 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2024-46704.

URL Resource
https://git.kernel.org/stable/c/8bc35475ef1a23b0e224f3242eb11c76cab0ea88 Patch
https://git.kernel.org/stable/c/91d09642127a32fde231face2ff489af70eef316 Patch

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2024-46704 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2024-46704 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Sep. 19, 2024

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
    Changed Reference Type https://git.kernel.org/stable/c/8bc35475ef1a23b0e224f3242eb11c76cab0ea88 No Types Assigned https://git.kernel.org/stable/c/8bc35475ef1a23b0e224f3242eb11c76cab0ea88 Patch
    Changed Reference Type https://git.kernel.org/stable/c/91d09642127a32fde231face2ff489af70eef316 No Types Assigned https://git.kernel.org/stable/c/91d09642127a32fde231face2ff489af70eef316 Patch
    Added CWE NIST NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.10 up to (excluding) 6.10.7 *cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:*
  • CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Sep. 13, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: workqueue: Fix spruious data race in __flush_work() When flushing a work item for cancellation, __flush_work() knows that it exclusively owns the work item through its PENDING bit. 134874e2eee9 ("workqueue: Allow cancel_work_sync() and disable_work() from atomic contexts on BH work items") added a read of @work->data to determine whether to use busy wait for BH work items that are being canceled. While the read is safe when @from_cancel, @work->data was read before testing @from_cancel to simplify code structure: data = *work_data_bits(work); if (from_cancel && !WARN_ON_ONCE(data & WORK_STRUCT_PWQ) && (data & WORK_OFFQ_BH)) { While the read data was never used if !@from_cancel, this could trigger KCSAN data race detection spuriously: ================================================================== BUG: KCSAN: data-race in __flush_work / __flush_work write to 0xffff8881223aa3e8 of 8 bytes by task 3998 on cpu 0: instrument_write include/linux/instrumented.h:41 [inline] ___set_bit include/asm-generic/bitops/instrumented-non-atomic.h:28 [inline] insert_wq_barrier kernel/workqueue.c:3790 [inline] start_flush_work kernel/workqueue.c:4142 [inline] __flush_work+0x30b/0x570 kernel/workqueue.c:4178 flush_work kernel/workqueue.c:4229 [inline] ... read to 0xffff8881223aa3e8 of 8 bytes by task 50 on cpu 1: __flush_work+0x42a/0x570 kernel/workqueue.c:4188 flush_work kernel/workqueue.c:4229 [inline] flush_delayed_work+0x66/0x70 kernel/workqueue.c:4251 ... value changed: 0x0000000000400000 -> 0xffff88810006c00d Reorganize the code so that @from_cancel is tested before @work->data is accessed. The only problem is triggering KCSAN detection spuriously. This shouldn't need READ_ONCE() or other access qualifiers. No functional changes.
    Added Reference kernel.org https://git.kernel.org/stable/c/91d09642127a32fde231face2ff489af70eef316 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/8bc35475ef1a23b0e224f3242eb11c76cab0ea88 [No types assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2024-46704 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2024-46704 weaknesses.

CVSS31 - Vulnerability Scoring System
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