CVE-2026-80792

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix use-after-free in ip6_finish_output2() ip6_finish_output2() caches a pointer to the IPv6 destination address (daddr) before invoking lwtunnel_xmit(). The LWT-BPF transmit path or other encapsulation operations within lwtunnel_xmit() can reallocate the skb head, freeing the memory that daddr points to. When lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, the function continues to use the stale daddr pointer to compute the nexthop and to look up or create the neighbour entry. This results in a use-after-free read, which can leak sensitive kernel data, pollute the neighbour table with arbitrary values, misdirect traffic, or crash the system. Fix this by re-fetching the IPv6 header and the destination address pointer after lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop computation and neighbour lookup operate on valid memory.

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a
https://git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862
https://git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43
https://git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3
https://git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a
https://git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515
https://git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed
https://git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e
https://git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-04 16:18

Updated : 2026-09-04 16:18

NVD link : CVE-2026-80792

Mitre link : CVE-2026-80792

CVE.ORG link : CVE-2026-80792

JSON object : View

Products Affected

No product.

CWE

No CWE.

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The LWT-BPF\ntransmit path or other encapsulation operations within\nlwtunnel_xmit() can reallocate the skb head, freeing the memory\nthat daddr points to. When lwtunnel_xmit() returns\nLWTUNNEL_XMIT_CONTINUE, the function continues to use the stale\ndaddr pointer to compute the nexthop and to look up or create the\nneighbour entry. This results in a use-after-free read, which can\nleak sensitive kernel data, pollute the neighbour table with\narbitrary values, misdirect traffic, or crash the system.\n\nFix this by re-fetching the IPv6 header and the destination\naddress pointer after lwtunnel_xmit() returns\nLWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop\ncomputation and neighbour lookup operate on valid memory."}], "lastModified": "2026-09-04T16:18:05.460", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}