{"id":"CVE-2024-46704","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-46704","generatedAt":"2026-10-28T08:27:20.650Z","title":"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.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nworkqueue: Fix spruious data race in __flush_work()\n\nWhen flushing a work item for cancellation, __flush_work() knows that it\nexclusively owns the work item through its PENDING bit. 134874e2eee9\n(\"workqueue: Allow cancel_work_sync() and disable_work() from atomic\ncontexts on BH work items\") added a read of @work->data to determine whether\nto use busy wait for BH work items that are being canceled. While the read\nis safe when @from_cancel, @work->data was read before testing @from_cancel\nto simplify code structure:\n\n\tdata = *work_data_bits(work);\n\tif (from_cancel &&\n\t    !WARN_ON_ONCE(data & WORK_STRUCT_PWQ) && (data & WORK_OFFQ_BH)) {\n\nWhile the read data was never used if !@from_cancel, this could trigger\nKCSAN data race detection spuriously:\n\n  ==================================================================\n  BUG: KCSAN: data-race in __flush_work / __flush_work\n\n  write to 0xffff8881223aa3e8 of 8 bytes by task 3998 on cpu 0:\n   instrument_write include/linux/instrumented.h:41 [inline]\n   ___set_bit include/asm-generic/bitops/instrumented-non-atomic.h:28 [inline]\n   insert_wq_barrier kernel/workqueue.c:3790 [inline]\n   start_flush_work kernel/workqueue.c:4142 [inline]\n   __flush_work+0x30b/0x570 kernel/workqueue.c:4178\n   flush_work kernel/workqueue.c:4229 [inline]\n   ...\n\n  read to 0xffff8881223aa3e8 of 8 bytes by task 50 on cpu 1:\n   __flush_work+0x42a/0x570 kernel/workqueue.c:4188\n   flush_work kernel/workqueue.c:4229 [inline]\n   flush_delayed_work+0x66/0x70 kernel/workqueue.c:4251\n   ...\n\n  value changed: 0x0000000000400000 -> 0xffff88810006c00d\n\nReorganize the code so that @from_cancel is tested before @work->data is\naccessed. The only problem is triggering KCSAN detection spuriously. This\nshouldn't need READ_ONCE() or other access qualifiers.\n\nNo functional changes.","published":"2024-09-13T07:15:05.000Z","lastModified":"2026-06-17T07:55:46.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":4.7,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":["linux/linux kernel"],"epss":{"score":0.00175,"percentile":0.06951,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.18%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/8bc35475ef1a23b0e224f3242eb11c76cab0ea88","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/91d09642127a32fde231face2ff489af70eef316","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-46704","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}