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CVE-2026-98925

bpf, sockmap: Fix self-redirect copied_seq double-counting PUBLISHED

Description (CNA)

In 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 (CNA)

Vendor / productVersions
Linux / Linuxaffected fe735073a50eaa71aceb2e990827fe26f33cddd6 before cf9aefb26a071cb8b6fdd761c27e022a1184946d; affected e5c6de5fa025882babf89cecbed80acf49b987fa before dc98def81e3c629e25fcdd5753b1db93aab27ce9; affected e5c6de5fa025882babf89cecbed80acf49b987fa before ef6f2182fee6b9721c005ccfc6aec0a47f79bbfa; affected e5c6de5fa025882babf89cecbed80acf49b987fa before ae1ffd04e98beefbe5d83335d506b0bcd5c2a6b3; affected e5c6de5fa025882babf89cecbed80acf49b987fa before 88942054191185c6f8bea5568cbb5614d1e99af9; affected e5c6de5fa025882babf89cecbed80acf49b987fa before 490a83d6386eec1d29f470c8d7331677fb46c3b7; affected f9b4a0b537be7a6e5f002ca64b09dcca9c14e6ed; affected 6.1.32 before 6.1.189; affected 6.3.6 before 6.4
Linux / Linuxaffected 6.4; unaffected 0 before 6.4; unaffected 6.1.189 through 6.1.*; unaffected 6.6.158 through 6.6.*; unaffected 6.12.112 through 6.12.*; unaffected 6.18.55 through 6.18.*; unaffected 7.2.9 through 7.2.*; unaffected 7.3 through *

CWE

No CWE identifiers supplied.

References