{"id":"CVE-2026-98925","title":"bpf, sockmap: Fix self-redirect copied_seq double-counting","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Fix self-redirect copied_seq double-counting\n\nWhen a BPF stream_verdict program redirects an skb back to the same\nsocket (self-redirect with BPF_F_INGRESS…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= fe735073a50eaa71aceb2e990827fe26f33cddd6 < cf9aefb26a071cb8b6fdd761c27e022a1184946d","Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < dc98def81e3c629e25fcdd5753b1db93aab27ce9","Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < ef6f2182fee6b9721c005ccfc6aec0a47f79bbfa","Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < ae1ffd04e98beefbe5d83335d506b0bcd5c2a6b3","Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < 88942054191185c6f8bea5568cbb5614d1e99af9","Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < 490a83d6386eec1d29f470c8d7331677fb46c3b7","Linux f9b4a0b537be7a6e5f002ca64b09dcca9c14e6ed","Linux >= 6.1.32 < 6.1.189","Linux >= 6.3.6 < 6.4","Linux 6.4"],"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T12:05:53.207Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98925","references":[{"url":"https://git.kernel.org/stable/c/cf9aefb26a071cb8b6fdd761c27e022a1184946d"},{"url":"https://git.kernel.org/stable/c/dc98def81e3c629e25fcdd5753b1db93aab27ce9"},{"url":"https://git.kernel.org/stable/c/ef6f2182fee6b9721c005ccfc6aec0a47f79bbfa"},{"url":"https://git.kernel.org/stable/c/ae1ffd04e98beefbe5d83335d506b0bcd5c2a6b3"},{"url":"https://git.kernel.org/stable/c/88942054191185c6f8bea5568cbb5614d1e99af9"},{"url":"https://git.kernel.org/stable/c/490a83d6386eec1d29f470c8d7331677fb46c3b7"}],"tags":["cve.org"],"ingestedAt":"2026-10-23T13:24:55.567Z","slug":"CVE-2026-98925","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Fix self-redirect copied_seq double-counting\n\nWhen a BPF stream_verdict program redirects an skb back to the same\nsocket (self-redirect with BPF_F_INGRESS), sk_psock_verdict_apply()\ncalls tcp_eat_skb() which advances tcp_sk->copied_seq. However, the\nskb is then delivered to the socket's psock ingress queue and later\nread by tcp_bpf_recvmsg_parser(), which also advances copied_seq via\nthe copied_from_self accounting path. This double-counting causes\ncopied_seq to advance by 2x the actual data length, triggering:\n\n  TCP recvmsg seq # bug 2: copied BF2E806, seq BF2E7FD, \\\n\t\t\t   rcvnxt BF2E806, fl 0\n  WARNING: net/ipv4/tcp.c:2745 at tcp_recvmsg_locked+0x72b/0x2640\n  Call Trace:\n   tcp_recvmsg+0x10a/0x500\n   sock_recvmsg+0x168/0x1d0\n   __sys_recvfrom+0x19a/0x2a0\n   __x64_sys_recvfrom+0xe4/0x1f0\n   do_syscall_64+0xf7/0x530\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  cleanup rbuf bug: copied BF2E806 seq BF2E806 rcvnxt BF2E806\n  WARNING: net/ipv4/tcp.c:1609 at tcp_cleanup_rbuf+0xf2/0x1c0\n  Call Trace:\n   tcp_recvmsg_locked+0x8d1/0x2640\n   tcp_recvmsg+0x10a/0x500\n   sock_recvmsg+0x168/0x1d0\n   __sys_recvfrom+0x19a/0x2a0\n   __x64_sys_recvfrom+0xe4/0x1f0\n   do_syscall_64+0xf7/0x530\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFix this by converting self-redirect verdict to __SK_PASS at the\nbeginning of sk_psock_verdict_apply(). This bypasses the\n__SK_REDIRECT case entirely (which calls sk_psock_eat_skb), letting\nthe __SK_PASS path queue the skb to the psock ingress queue. The\ndata is then read via tcp_bpf_recvmsg_parser(), which advances\ncopied_seq exactly once through copied_from_self. Cross-socket\nredirects continue through __SK_REDIRECT with sk_psock_eat_skb()\nunchanged.\n\n## Affected\n\n- `Linux >= fe735073a50eaa71aceb2e990827fe26f33cddd6 < cf9aefb26a071cb8b6fdd761c27e022a1184946d`\n- `Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < dc98def81e3c629e25fcdd5753b1db93aab27ce9`\n- `Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < ef6f2182fee6b9721c005ccfc6aec0a47f79bbfa`\n- `Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < ae1ffd04e98beefbe5d83335d506b0bcd5c2a6b3`\n- `Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < 88942054191185c6f8bea5568cbb5614d1e99af9`\n- `Linux >= e5c6de5fa025882babf89cecbed80acf49b987fa < 490a83d6386eec1d29f470c8d7331677fb46c3b7`\n- `Linux f9b4a0b537be7a6e5f002ca64b09dcca9c14e6ed`\n- `Linux >= 6.1.32 < 6.1.189`\n- `Linux >= 6.3.6 < 6.4`\n- `Linux 6.4`\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":[]}