CVE-2017-18261

Severity: medium (CVSS 5.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-04-19 · updated 2026-06-17
Weakness: CWE-835

Description

The arch_timer_reg_read_stable macro in arch/arm64/include/asm/arch_timer.h in the Linux kernel before 4.13 allows local users to cause a denial of service (infinite recursion) by writing to a file under /sys/kernel/debug in certain circumstances, as demonstrated by a scenario involving debugfs, ftrace, PREEMPT_TRACER, and FUNCTION_GRAPH_TRACER.

Affected products

Linux kernel: before 4.13 — fixed in 4.13

How to fix

Upgrade to a fixed version: Linux kernel 4.13. Check the vendor advisory for mitigations.

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=adb4f11e0a8f4e29900adb2b7af28b6bbd5c1fa4
https://github.com/torvalds/linux/commit/adb4f11e0a8f4e29900adb2b7af28b6bbd5c1fa4
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=adb4f11e0a8f4e29900adb2b7af28b6bbd5c1fa4
https://github.com/torvalds/linux/commit/adb4f11e0a8f4e29900adb2b7af28b6bbd5c1fa4

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