CVE-2026-22987: net/sched: act_api: avoid dereferencing ERR_PTR in tcf_idrinfo_destroy

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-23 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_api: avoid dereferencing ERR_PTR in tcf_idrinfo_destroy syzbot reported a crash in tc_act_in_hw() during netns teardown where tcf_idrinfo_destroy() passed an ERR_PTR(-EBUSY) value as a tc_action pointer, leading to an invalid dereference. Guard against ERR_PTR entries when iterating the action IDR so teardown does not call tc_act_in_hw() on an error pointer.

Affected products

Linux kernel: from 6.17 before 6.18.6; 6.19-rc1, 6.19-rc2, 6.19-rc3, 6.19-rc4 — fixed in 6.18.6

How to fix

Upgrade to a fixed version: Linux kernel 6.18.6. Check the vendor advisory for mitigations.

References

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