{"id":"CVE-2026-98371","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix runt reassembly panic from short inner tot_len\n\nWhen the start of an inner packet is split across two outer packets\nsuch that fewer than 4 bytes land a…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix runt reassembly panic from short inner tot_len\n\nWhen the start of an inner packet is split across two outer packets\nsuch that fewer than 4 bytes land a…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 07569476544681816335099929ff3494dfbf6b05 < a7018ee0ea8622ed59edc064be4e0f2c26464f53","Linux >= 07569476544681816335099929ff3494dfbf6b05 < 5b8afb56ccb7c014b0f1ac40341708b200443c2d","Linux >= 07569476544681816335099929ff3494dfbf6b05 < dc33262be1fe43d0eb0b84fb58c6ed42e2f64a8c","Linux 6.14"],"published":"2026-10-06","updated":"2026-10-06","sourceUpdated":"2026-10-06T09:18:31.613","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98371","references":[{"url":"https://git.kernel.org/stable/c/5b8afb56ccb7c014b0f1ac40341708b200443c2d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a7018ee0ea8622ed59edc064be4e0f2c26464f53","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dc33262be1fe43d0eb0b84fb58c6ed42e2f64a8c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-06T08:50:17.390Z","slug":"CVE-2026-98371","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix runt reassembly panic from short inner tot_len\n\nWhen the start of an inner packet is split across two outer packets\nsuch that fewer than 4 bytes land at the end of the first one,\n__input_process_payload() saves those bytes as a runt and skips the\niplen/iphlen validation performed for in-place packets. When the\ncontinuation packet arrives, iptfs_reassem_cont() only requires the\ndeclared inner length to be >= sizeof(ra_runt) (6) before allocating\nthe reassembly skb with that attacker-controlled length.\n\nHowever, __iptfs_iphlen() always returns the fixed minimum IP header\nsize (20 for IPv4, 40 for IPv6), so for an inner IPv4 tot_len in\n[6, 19] the header-completion copy writes past the declared packet\nlength, and the subsequent \"ipremain -= copylen\" underflows to ~4GB,\nleaving the payload copy length bounded only by blkoff (up to 64KB).\nAt runtime the skb_put() tailroom check turns this into\nskb_over_panic(), i.e. an unprivileged kernel panic (DoS), reachable\nlocally via userns+netns IPTFS SAs and remotely against IPTFS VPN\ngateways when the decrypted outer skb is linear (e.g. AF_PACKET taps,\ntun/tap delivery).\n\nAlign the runt path with the normal path by requiring the declared\ninner length to cover at least the IP header size. This also subsumes\nthe previous >= sizeof(ra_runt) check, since the minimum IP header\nis always larger than the runt buffer.\n\nThis issue was found by the autokbug dynamic kernel fuzzer at\nTencent Yunding Lab.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}