CVE-2021-47321

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < 58606882ad8ec6c39e0f40344b922921ef94ab4daffected
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < ca96b8ea5e74956071154bdb456778cc3027e79faffected
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < 8bec568d7518b1504a602ed5376bb322e4dbb270affected
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < ecd620e0fb1ff7f78fdb593379b2e6938c99707aaffected
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < db222f1477ad5692cd454709b714949807e5d111affected
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < 66ba9cf929b1c4fabf545bd4c18f6f64e23e46e4affected
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < 4c05dac488a660fe2925c047ecb119e7afaaeb1eaffected
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < 1a053c4d716898a53c2e31c574a70ea0c37044a3affected
LinuxLinux7c25f8c9f67708e6464d2221bc311cbd99e950dc < d0212f095ab56672f6f36aabc605bda205e1e0bfaffected
LinuxLinux4.3affected
LinuxLinux0 < 4.3unaffected
LinuxLinux4.4.276 <= 4.4.*unaffected
LinuxLinux4.9.276 <= 4.9.*unaffected
LinuxLinux4.14.240 <= 4.14.*unaffected
LinuxLinux4.19.198 <= 4.19.*unaffected
LinuxLinux5.4.134 <= 5.4.*unaffected
LinuxLinux5.10.52 <= 5.10.*unaffected
LinuxLinux5.12.19 <= 5.12.*unaffected
LinuxLinux5.13.4 <= 5.13.*unaffected
LinuxLinux5.14 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References