Bug 2436776 (CVE-2026-23048)

Summary: CVE-2026-23048 kernel: udp: call skb_orphan() before skb_attempt_defer_free()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2026-02-04 17:02:49 UTC
In the Linux kernel, the following vulnerability has been resolved:

udp: call skb_orphan() before skb_attempt_defer_free()

Standard UDP receive path does not use skb->destructor.

But skmsg layer does use it, since it calls skb_set_owner_sk_safe()
from udp_read_skb().

This then triggers this warning in skb_attempt_defer_free():

    DEBUG_NET_WARN_ON_ONCE(skb->destructor);

We must call skb_orphan() to fix this issue.