Bug 2454807 (CVE-2026-23442)

Summary: CVE-2026-23442 kernel: ipv6: add NULL checks for idev in SRv6 paths
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. Missing null pointer checks in the IPv6 Segment Routing (SRv6) implementation, specifically within the `seg6_hmac_validate_skb()` and `ipv6_srh_rcv()` functions, can occur when an IPv6 device lacks proper configuration. This oversight may allow an attacker to trigger a null pointer dereference, potentially leading to a system crash and a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-04-03 16:01:47 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ipv6: add NULL checks for idev in SRv6 paths

__in6_dev_get() can return NULL when the device has no IPv6 configuration
(e.g. MTU < IPV6_MIN_MTU or after NETDEV_UNREGISTER).

Add NULL checks for idev returned by __in6_dev_get() in both
seg6_hmac_validate_skb() and ipv6_srh_rcv() to prevent potential NULL
pointer dereferences.
Comment 1 Jon Moroney 2026-04-03 19:29:34 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026040314-CVE-2026-23442-fe23@gregkh/T