Description
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 products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
fe735073a50eaa71aceb2e990827fe26f33cddd6 to < cf9aefb26a071cb8b6fdd761c27e022a1184946daffectede5c6de5fa025882babf89cecbed80acf49b987fa to < dc98def81e3c629e25fcdd5753b1db93aab27ce9affectede5c6de5fa025882babf89cecbed80acf49b987fa to < ef6f2182fee6b9721c005ccfc6aec0a47f79bbfaaffectede5c6de5fa025882babf89cecbed80acf49b987fa to < ae1ffd04e98beefbe5d83335d506b0bcd5c2a6b3affectede5c6de5fa025882babf89cecbed80acf49b987fa to < 88942054191185c6f8bea5568cbb5614d1e99af9affectede5c6de5fa025882babf89cecbed80acf49b987fa to < 490a83d6386eec1d29f470c8d7331677fb46c3b7affectedf9b4a0b537be7a6e5f002ca64b09dcca9c14e6edaffected6.1.32 to < 6.1.189affected6.3.6 to < 6.4affected
Linux Linux
Default version status: affected
6.4affected0 to < 6.4unaffected6.1.189 to ≤ 6.1.*unaffected6.6.158 to ≤ 6.6.*unaffected6.12.112 to ≤ 6.12.*unaffected6.18.55 to ≤ 6.18.*unaffected7.2.9 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/cf9aefb26a071cb8b6fdd761c27e022a1184946d ↗
- https://git.kernel.org/stable/c/dc98def81e3c629e25fcdd5753b1db93aab27ce9 ↗
- https://git.kernel.org/stable/c/ef6f2182fee6b9721c005ccfc6aec0a47f79bbfa ↗
- https://git.kernel.org/stable/c/ae1ffd04e98beefbe5d83335d506b0bcd5c2a6b3 ↗
- https://git.kernel.org/stable/c/88942054191185c6f8bea5568cbb5614d1e99af9 ↗
- https://git.kernel.org/stable/c/490a83d6386eec1d29f470c8d7331677fb46c3b7 ↗