{"id":"CVE-2021-47324","state":"PUBLISHED","title":"watchdog: Fix possible use-after-free in wdt_startup()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nwatchdog: Fix possible use-after-free in wdt_startup()\n\nThis module's remove path calls del_timer(). However, that function\ndoes not wait until the timer handler finishes. This means that the\ntimer handler may still be running after the driver's remove function\nhas finished, which would result in a use-after-free.\n\nFix by calling del_timer_sync(), which makes sure the timer handler\nhas finished, and unable to re-schedule itself.","publishedAt":"2024-05-21T14:35:37.844Z","updatedAt":"2026-05-11T13:52:17.710Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"CISA-ADP"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"63a3dc24bd053792f84cb4eef0168b1266202a02","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"862f2b5a7c38762ac9e369daefbf361a91aca685","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0ac50a76cf3cd63db000648b3b19f3f98b8aaa76","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"dc9403097be52d57a5c9c35efa9be79d166a78af","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"146cc288fb80c662c9c35e7bc58325d1ac0a7875","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"a397cb4576fc2fc802562418b3a50b8f67d60d31","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b4ebf4a4692e84163a69444c70ad515de06e2259","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"c08a6b31e4917034f0ed0cb457c3bb209576f542","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/watchdog/sbc60xxwdt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"4.4.276","status":"unaffected","lessThanOrEqual":"4.4.*","versionType":"semver"},{"version":"4.9.276","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.240","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.198","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.134","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.52","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.12.19","status":"unaffected","lessThanOrEqual":"5.12.*","versionType":"semver"},{"version":"5.13.4","status":"unaffected","lessThanOrEqual":"5.13.*","versionType":"semver"},{"version":"5.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/watchdog/sbc60xxwdt.c"]}],"references":["https://git.kernel.org/stable/c/63a3dc24bd053792f84cb4eef0168b1266202a02","https://git.kernel.org/stable/c/862f2b5a7c38762ac9e369daefbf361a91aca685","https://git.kernel.org/stable/c/0ac50a76cf3cd63db000648b3b19f3f98b8aaa76","https://git.kernel.org/stable/c/dc9403097be52d57a5c9c35efa9be79d166a78af","https://git.kernel.org/stable/c/146cc288fb80c662c9c35e7bc58325d1ac0a7875","https://git.kernel.org/stable/c/a397cb4576fc2fc802562418b3a50b8f67d60d31","https://git.kernel.org/stable/c/b4ebf4a4692e84163a69444c70ad515de06e2259","https://git.kernel.org/stable/c/8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90","https://git.kernel.org/stable/c/c08a6b31e4917034f0ed0cb457c3bb209576f542"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47324.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47324","state":"PUBLISHED","datePublished":"2024-05-21T14:35:37.844Z","dateUpdated":"2026-05-11T13:52:17.710Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-05-21T14:28:16.974Z"},"containers":{"cna":{"title":"watchdog: Fix possible use-after-free in wdt_startup()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nwatchdog: Fix possible use-after-free in wdt_startup()\n\nThis module's remove path calls del_timer(). 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