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Vulnerability · Published May 21, 2024 · Assigned by Linux

CVE-2021-47324watchdog: Fix possible use-after-free in wdt_startup()

High 8.8

In plain English

A high-severity use-after-free in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 67% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)1.2%top 32.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: watchdog: Fix possible use-after-free in wdt_startup() This module'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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.14.6-1DEBIAN-CVE-2021-47324
Debian:13linux5.14.6-1DEBIAN-CVE-2021-47324
Debian:14linux5.14.6-1DEBIAN-CVE-2021-47324
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2021-47324
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2021-47324
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2021-47324

Affected products (as reported)

VendorProductVersions
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 63a3dc24bd053792f84cb4eef0168b1266202a021da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 862f2b5a7c38762ac9e369daefbf361a91aca6851da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 0ac50a76cf3cd63db000648b3b19f3f98b8aaa761da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before dc9403097be52d57a5c9c35efa9be79d166a78af1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 146cc288fb80c662c9c35e7bc58325d1ac0a78751da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before a397cb4576fc2fc802562418b3a50b8f67d60d311da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before b4ebf4a4692e84163a69444c70ad515de06e22591da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 8adbbe6c86bb13e14f8a19e036ae5f4f5661fd90
Linux Linux 2.6.12

Weakness: CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References