GHSA-QJHH-724F-RP7Q
Vulnerability from github – Published: 2026-10-23 15:31 – Updated: 2026-10-23 15:31In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix self-redirect copied_seq double-counting
When a BPF stream_verdict program redirects an skb back to the same socket (self-redirect with BPF_F_INGRESS), sk_psock_verdict_apply() calls tcp_eat_skb() which advances tcp_sk->copied_seq. However, the skb is then delivered to the socket's psock ingress queue and later read by tcp_bpf_recvmsg_parser(), which also advances copied_seq via the copied_from_self accounting path. This double-counting causes copied_seq to advance by 2x the actual data length, triggering:
TCP recvmsg seq # bug 2: copied BF2E806, seq BF2E7FD, \ rcvnxt BF2E806, fl 0 WARNING: net/ipv4/tcp.c:2745 at tcp_recvmsg_locked+0x72b/0x2640 Call Trace: tcp_recvmsg+0x10a/0x500 sock_recvmsg+0x168/0x1d0 __sys_recvfrom+0x19a/0x2a0 __x64_sys_recvfrom+0xe4/0x1f0 do_syscall_64+0xf7/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f
cleanup rbuf bug: copied BF2E806 seq BF2E806 rcvnxt BF2E806 WARNING: net/ipv4/tcp.c:1609 at tcp_cleanup_rbuf+0xf2/0x1c0 Call Trace: tcp_recvmsg_locked+0x8d1/0x2640 tcp_recvmsg+0x10a/0x500 sock_recvmsg+0x168/0x1d0 __sys_recvfrom+0x19a/0x2a0 __x64_sys_recvfrom+0xe4/0x1f0 do_syscall_64+0xf7/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Fix this by converting self-redirect verdict to __SK_PASS at the beginning of sk_psock_verdict_apply(). This bypasses the __SK_REDIRECT case entirely (which calls sk_psock_eat_skb), letting the __SK_PASS path queue the skb to the psock ingress queue. The data is then read via tcp_bpf_recvmsg_parser(), which advances copied_seq exactly once through copied_from_self. Cross-socket redirects continue through __SK_REDIRECT with sk_psock_eat_skb() unchanged.
{
"affected": [],
"aliases": [
"CVE-2026-98925"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-10-23T13:17:13Z",
"severity": null
},
"details": "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), sk_psock_verdict_apply()\ncalls tcp_eat_skb() which advances tcp_sk-\u003ecopied_seq. However, the\nskb is then delivered to the socket\u0027s 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.",
"id": "GHSA-qjhh-724f-rp7q",
"modified": "2026-10-23T15:31:31Z",
"published": "2026-10-23T15:31:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98925"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/490a83d6386eec1d29f470c8d7331677fb46c3b7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/88942054191185c6f8bea5568cbb5614d1e99af9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ae1ffd04e98beefbe5d83335d506b0bcd5c2a6b3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cf9aefb26a071cb8b6fdd761c27e022a1184946d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dc98def81e3c629e25fcdd5753b1db93aab27ce9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ef6f2182fee6b9721c005ccfc6aec0a47f79bbfa"
}
],
"schema_version": "1.4.0",
"severity": []
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.