CVE-2021-47321
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().
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.25%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.25% probability · 16th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/1a053c4d716898a53c2e31c574a70ea0c37044a3Patch
- https://git.kernel.org/stable/c/4c05dac488a660fe2925c047ecb119e7afaaeb1ePatch
- https://git.kernel.org/stable/c/58606882ad8ec6c39e0f40344b922921ef94ab4dPatch
- https://git.kernel.org/stable/c/66ba9cf929b1c4fabf545bd4c18f6f64e23e46e4Patch
- https://git.kernel.org/stable/c/8bec568d7518b1504a602ed5376bb322e4dbb270Patch
- https://git.kernel.org/stable/c/ca96b8ea5e74956071154bdb456778cc3027e79fPatch
- https://git.kernel.org/stable/c/d0212f095ab56672f6f36aabc605bda205e1e0bfPatch
- https://git.kernel.org/stable/c/db222f1477ad5692cd454709b714949807e5d111Patch
- https://git.kernel.org/stable/c/ecd620e0fb1ff7f78fdb593379b2e6938c99707aPatch
- https://git.kernel.org/stable/c/1a053c4d716898a53c2e31c574a70ea0c37044a3Patch
- https://git.kernel.org/stable/c/4c05dac488a660fe2925c047ecb119e7afaaeb1ePatch
- https://git.kernel.org/stable/c/58606882ad8ec6c39e0f40344b922921ef94ab4dPatch
- https://git.kernel.org/stable/c/66ba9cf929b1c4fabf545bd4c18f6f64e23e46e4Patch
- https://git.kernel.org/stable/c/8bec568d7518b1504a602ed5376bb322e4dbb270Patch
- https://git.kernel.org/stable/c/ca96b8ea5e74956071154bdb456778cc3027e79fPatch
- https://git.kernel.org/stable/c/d0212f095ab56672f6f36aabc605bda205e1e0bfPatch
- https://git.kernel.org/stable/c/db222f1477ad5692cd454709b714949807e5d111Patch
- https://git.kernel.org/stable/c/ecd620e0fb1ff7f78fdb593379b2e6938c99707aPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.