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CVE-2021-47321
watchdog: Fix possible use-after-free by calling del_timer_sync()
High7.8EPSS 0.25%
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: watchdog: Fix possible use-after-free by calling del_timer_sync() This driver's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.25% · top 84% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < 58606882ad8ec6c39e0f40344b922921ef94ab4d
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < ca96b8ea5e74956071154bdb456778cc3027e79f
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < 8bec568d7518b1504a602ed5376bb322e4dbb270
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < ecd620e0fb1ff7f78fdb593379b2e6938c99707a
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < db222f1477ad5692cd454709b714949807e5d111
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < 66ba9cf929b1c4fabf545bd4c18f6f64e23e46e4
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < 4c05dac488a660fe2925c047ecb119e7afaaeb1e
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < 1a053c4d716898a53c2e31c574a70ea0c37044a3
- affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc – < d0212f095ab56672f6f36aabc605bda205e1e0bf
- affected 4.3
- unaffected < 4.3
- unaffected 4.4.276 – ≤ 4.4.*
- unaffected 4.9.276 – ≤ 4.9.*
- unaffected 4.14.240 – ≤ 4.14.*
- unaffected 4.19.198 – ≤ 4.19.*
- unaffected 5.4.134 – ≤ 5.4.*
- unaffected 5.10.52 – ≤ 5.10.*
- unaffected 5.12.19 – ≤ 5.12.*
- unaffected 5.13.4 – ≤ 5.13.*
- unaffected 5.14 – ≤ *
References (9)
- https://git.kernel.org/stable/c/58606882ad8ec6c39e0f40344b922921ef94ab4d (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/ca96b8ea5e74956071154bdb456778cc3027e79f (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/8bec568d7518b1504a602ed5376bb322e4dbb270 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/ecd620e0fb1ff7f78fdb593379b2e6938c99707a (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/db222f1477ad5692cd454709b714949807e5d111 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/66ba9cf929b1c4fabf545bd4c18f6f64e23e46e4 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/4c05dac488a660fe2925c047ecb119e7afaaeb1e (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/1a053c4d716898a53c2e31c574a70ea0c37044a3 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/d0212f095ab56672f6f36aabc605bda205e1e0bf (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2021-47321)Record last updated .