Bug 2432377 (CVE-2026-22987)

Summary: CVE-2026-22987 kernel: Linux kernel: Denial of Service due to invalid dereference in networking scheduler during netns teardown
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in the Linux kernel's networking scheduler component (net/sched: act_api). A local user with low privileges could exploit this vulnerability during network namespace (netns) teardown. The tcf_idrinfo_destroy function incorrectly dereferences an error pointer, leading to a system crash (Denial of Service).
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Description OSIDB Bzimport 2026-01-23 16:01:39 UTC 
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.
Comment 1 Keith Grant 2026-01-23 19:37:49 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026012350-CVE-2026-22987-8984@gregkh/T