CVE-2021-47321

watchdog: Fix possible use-after-free by calling del_timer_sync()

State: Published
Severity: Not scored
Published: May 21, 2024
Updated: May 11, 2026
Reserved: May 21, 2024

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

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 58606882ad8ec6c39e0f40344b922921ef94ab4dAffected 7c25f8c9f67708e6464d2221bc311cbd99e950dc to before ca96b8ea5e74956071154bdb456778cc3027e79fAffected 7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 8bec568d7518b1504a602ed5376bb322e4dbb270Affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc to before ecd620e0fb1ff7f78fdb593379b2e6938c99707aAffected 7c25f8c9f67708e6464d2221bc311cbd99e950dc to before db222f1477ad5692cd454709b714949807e5d111Affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 66ba9cf929b1c4fabf545bd4c18f6f64e23e46e4Affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 4c05dac488a660fe2925c047ecb119e7afaaeb1eAffected 7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 1a053c4d716898a53c2e31c574a70ea0c37044a3Affected 7c25f8c9f67708e6464d2221bc311cbd99e950dc to before d0212f095ab56672f6f36aabc605bda205e1e0bfAffected
LinuxLinux	4.3Affected before 4.3Not affected 4.4.276 through 4.4.Not affected 4.9.276 through 4.9.Not affected 4.14.240 through 4.14.Not affected 4.19.198 through 4.19.Not affected 5.4.134 through 5.4.Not affected 5.10.52 through 5.10.Not affected 5.12.19 through 5.12.Not affected 5.13.4 through 5.13.Not affected 5.14 and laterNot affected

Product

Versions

LinuxLinux

7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 58606882ad8ec6c39e0f40344b922921ef94ab4dAffected
7c25f8c9f67708e6464d2221bc311cbd99e950dc to before ca96b8ea5e74956071154bdb456778cc3027e79fAffected
7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 8bec568d7518b1504a602ed5376bb322e4dbb270Affected
7c25f8c9f67708e6464d2221bc311cbd99e950dc to before ecd620e0fb1ff7f78fdb593379b2e6938c99707aAffected
7c25f8c9f67708e6464d2221bc311cbd99e950dc to before db222f1477ad5692cd454709b714949807e5d111Affected
7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 66ba9cf929b1c4fabf545bd4c18f6f64e23e46e4Affected
7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 4c05dac488a660fe2925c047ecb119e7afaaeb1eAffected
7c25f8c9f67708e6464d2221bc311cbd99e950dc to before 1a053c4d716898a53c2e31c574a70ea0c37044a3Affected
7c25f8c9f67708e6464d2221bc311cbd99e950dc to before d0212f095ab56672f6f36aabc605bda205e1e0bfAffected

LinuxLinux

4.3Affected
before 4.3Not affected
4.4.276 through 4.4.*Not affected
4.9.276 through 4.9.*Not affected
4.14.240 through 4.14.*Not affected
4.19.198 through 4.19.*Not affected
5.4.134 through 5.4.*Not affected
5.10.52 through 5.10.*Not affected
5.12.19 through 5.12.*Not affected
5.13.4 through 5.13.*Not affected
5.14 and laterNot affected

References

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