CVE-2021-47323

watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff()

State: Published
Severity: 8.8 High
Published: May 21, 2024
Updated: May 11, 2026
Reserved: May 21, 2024

Description

In the Linux kernel, the following vulnerability has been resolved:

watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff()

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.

Scores

CVSS	Score	Vector	Source
3.1	8.8 High	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	CISA-ADP

Weaknesses

CWE-416 Use After Free

Affected Products

Product	Versions
LinuxLinux	1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 0015581a79bbf8e521f85dddb7d3e4a66b9f51d4Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b4565a8a2d6bffb05bfbec11399d261ec16fe373Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 2aef07017fae21c3d8acea9656b10e3b9c0f1e04Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 522e75ed63f67e815d4ec0deace67df22d9ce78eAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 7c56c5508dc20a6b133bc669fc34327a6711c24cAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b3c41ea5bc34d8c7b19e230d80e0e555c6f5057dAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before f0feab82f6a0323f54d85e8b512a2be64f83648aAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 90b7c141132244e8e49a34a4c1e445cce33e07f4Affected
LinuxLinux	2.6.12Affected before 2.6.12Not 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

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 0015581a79bbf8e521f85dddb7d3e4a66b9f51d4Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b4565a8a2d6bffb05bfbec11399d261ec16fe373Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 2aef07017fae21c3d8acea9656b10e3b9c0f1e04Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 522e75ed63f67e815d4ec0deace67df22d9ce78eAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 7c56c5508dc20a6b133bc669fc34327a6711c24cAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b3c41ea5bc34d8c7b19e230d80e0e555c6f5057dAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before f0feab82f6a0323f54d85e8b512a2be64f83648aAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 90b7c141132244e8e49a34a4c1e445cce33e07f4Affected

LinuxLinux

2.6.12Affected
before 2.6.12Not 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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