kernel/linux.git/net/ipv6/syncookies.c, branch v6.12.80

tcp: use sk_skb_reason_drop to free rx packets

2024-06-19T11:44:22+00:00

Replace kfree_skb_reason with sk_skb_reason_drop and pass the receiving socket to the tracepoint. Reported-by: kernel test robot Closes: https://lore.kernel.org/r/202406011539.jhwBd7DX-lkp@intel.com/ Signed-off-by: Yan Zhai Acked-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller

tcp: annotate data-races around tp->window_clamp

2024-04-06T05:32:37+00:00

tp->window_clamp can be read locklessly, add READ_ONCE() and WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet Reviewed-by: Jason Xing Link: https://lore.kernel.org/r/20240404114231.2195171-1-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: Clear req->syncookie in reqsk_alloc().

2024-03-20T02:35:59+00:00

syzkaller reported a read of uninit req->syncookie. [0] Originally, req->syncookie was used only in tcp_conn_request() to indicate if we need to encode SYN cookie in SYN+ACK, so the field remains uninitialised in other places. The commit 695751e31a63 ("bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check().") added another meaning in ACK path; req->syncookie is set true if SYN cookie is validated by BPF kfunc. After the change, cookie_v[46]_check() always read req->syncookie, but it is not initialised in the normal SYN cookie case as reported by KMSAN. Let's make sure we always initialise req->syncookie in reqsk_alloc(). [0]: BUG: KMSAN: uninit-value in cookie_v4_check+0x22b7/0x29e0 net/ipv4/syncookies.c:477 cookie_v4_check+0x22b7/0x29e0 net/ipv4/syncookies.c:477 tcp_v4_cookie_check net/ipv4/tcp_ipv4.c:1855 [inline] tcp_v4_do_rcv+0xb17/0x10b0 net/ipv4/tcp_ipv4.c:1914 tcp_v4_rcv+0x4ce4/0x5420 net/ipv4/tcp_ipv4.c:2322 ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x332/0x500 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_rcv_finish+0x4a2/0x520 net/ipv4/ip_input.c:449 NF_HOOK include/linux/netfilter.h:314 [inline] ip_rcv+0xcd/0x380 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5538 [inline] __netif_receive_skb+0x319/0x9e0 net/core/dev.c:5652 process_backlog+0x480/0x8b0 net/core/dev.c:5981 __napi_poll+0xe7/0x980 net/core/dev.c:6632 napi_poll net/core/dev.c:6701 [inline] net_rx_action+0x89d/0x1820 net/core/dev.c:6813 __do_softirq+0x1c0/0x7d7 kernel/softirq.c:554 do_softirq+0x9a/0x100 kernel/softirq.c:455 __local_bh_enable_ip+0x9f/0xb0 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:820 [inline] __dev_queue_xmit+0x2776/0x52c0 net/core/dev.c:4362 dev_queue_xmit include/linux/netdevice.h:3091 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0x187a/0x1b70 net/ipv4/ip_output.c:235 __ip_finish_output+0x287/0x810 ip_finish_output+0x4b/0x550 net/ipv4/ip_output.c:323 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip_output+0x15f/0x3f0 net/ipv4/ip_output.c:433 dst_output include/net/dst.h:450 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x1e93/0x2030 net/ipv4/ip_output.c:535 ip_queue_xmit+0x60/0x80 net/ipv4/ip_output.c:549 __tcp_transmit_skb+0x3c70/0x4890 net/ipv4/tcp_output.c:1462 tcp_transmit_skb net/ipv4/tcp_output.c:1480 [inline] tcp_write_xmit+0x3ee1/0x8900 net/ipv4/tcp_output.c:2792 __tcp_push_pending_frames net/ipv4/tcp_output.c:2977 [inline] tcp_send_fin+0xa90/0x12e0 net/ipv4/tcp_output.c:3578 tcp_shutdown+0x198/0x1f0 net/ipv4/tcp.c:2716 inet_shutdown+0x33f/0x5b0 net/ipv4/af_inet.c:923 __sys_shutdown_sock net/socket.c:2425 [inline] __sys_shutdown net/socket.c:2437 [inline] __do_sys_shutdown net/socket.c:2445 [inline] __se_sys_shutdown+0x2a4/0x440 net/socket.c:2443 __x64_sys_shutdown+0x6c/0xa0 net/socket.c:2443 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was stored to memory at: reqsk_alloc include/net/request_sock.h:148 [inline] inet_reqsk_alloc+0x651/0x7a0 net/ipv4/tcp_input.c:6978 cookie_tcp_reqsk_alloc+0xd4/0x900 net/ipv4/syncookies.c:328 cookie_tcp_check net/ipv4/syncookies.c:388 [inline] cookie_v4_check+0x289f/0x29e0 net/ipv4/syncookies.c:420 tcp_v4_cookie_check net/ipv4/tcp_ipv4.c:1855 [inline] tcp_v4_do_rcv+0xb17/0x10b0 net/ipv4/tcp_ipv4.c:1914 tcp_v4_rcv+0x4ce4/0x5420 net/ipv4/tcp_ipv4.c:2322 ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x332/0x500 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_rcv_finish+0x4a2/0x520 net/ipv4/ip_input.c:449 NF_HOOK include/linux/netfilter.h:314 [inline] ip_rcv+0xcd/0x380 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5538 [inline] __netif_receive_skb+0x319/0x9e0 net/core/dev.c:5652 process_backlog+0x480/0x8b0 net/core/dev.c:5981 __napi_poll+0xe7/0x980 net/core/dev.c:6632 napi_poll net/core/dev.c:6701 [inline] net_rx_action+0x89d/0x1820 net/core/dev.c:6813 __do_softirq+0x1c0/0x7d7 kernel/softirq.c:554 Uninit was created at: __alloc_pages+0x9a7/0xe00 mm/page_alloc.c:4592 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2175 [inline] allocate_slab mm/slub.c:2338 [inline] new_slab+0x2de/0x1400 mm/slub.c:2391 ___slab_alloc+0x1184/0x33d0 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmem_cache_alloc+0x6d3/0xbe0 mm/slub.c:3852 reqsk_alloc include/net/request_sock.h:131 [inline] inet_reqsk_alloc+0x66/0x7a0 net/ipv4/tcp_input.c:6978 tcp_conn_request+0x484/0x44e0 net/ipv4/tcp_input.c:7135 tcp_v4_conn_request+0x16f/0x1d0 net/ipv4/tcp_ipv4.c:1716 tcp_rcv_state_process+0x2e5/0x4bb0 net/ipv4/tcp_input.c:6655 tcp_v4_do_rcv+0xbfd/0x10b0 net/ipv4/tcp_ipv4.c:1929 tcp_v4_rcv+0x4ce4/0x5420 net/ipv4/tcp_ipv4.c:2322 ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x332/0x500 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0x15f3/0x17f0 net/ipv4/ip_input.c:639 ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5581 [inline] __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5629 __netif_receive_skb_list net/core/dev.c:5681 [inline] netif_receive_skb_list_internal+0x106c/0x16f0 net/core/dev.c:5773 gro_normal_list include/net/gro.h:438 [inline] napi_complete_done+0x425/0x880 net/core/dev.c:6113 virtqueue_napi_complete drivers/net/virtio_net.c:465 [inline] virtnet_poll+0x149d/0x2240 drivers/net/virtio_net.c:2211 __napi_poll+0xe7/0x980 net/core/dev.c:6632 napi_poll net/core/dev.c:6701 [inline] net_rx_action+0x89d/0x1820 net/core/dev.c:6813 __do_softirq+0x1c0/0x7d7 kernel/softirq.c:554 CPU: 0 PID: 16792 Comm: syz-executor.2 Not tainted 6.8.0-syzkaller-05562-g61387b8dcf1d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Fixes: 695751e31a63 ("bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check().") Reported-by: syzkaller Reported-by: Eric Dumazet Closes: https://lore.kernel.org/bpf/CANn89iKdN9c+C_2JAUbc+VY3DDQjAQukMtiBbormAmAk9CdvQA@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/r/20240315224710.55209-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

tcp: use drop reasons in cookie check for ipv6

2024-02-28T10:39:21+00:00

Like what I did to ipv4 mode, refine this part: adding more drop reasons for better tracing. Signed-off-by: Jason Xing Reviewed-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

tcp: directly drop skb in cookie check for ipv6

2024-02-28T10:39:21+00:00

Like previous patch does, only moving skb drop logical code to cookie_v6_check() for later refinement. Signed-off-by: Jason Xing Reviewed-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check().

2024-01-23T22:40:24+00:00

We will support arbitrary SYN Cookie with BPF in the following patch. If BPF prog validates ACK and kfunc allocates a reqsk, it will be carried to cookie_[46]_check() as skb->sk. If skb->sk is not NULL, we call cookie_bpf_check(). Then, we clear skb->sk and skb->destructor, which are needed not to hold refcnt for reqsk and the listener. See the following patch for details. After that, we finish initialisation for the remaining fields with cookie_tcp_reqsk_init(). Note that the server side WScale is set only for non-BPF SYN Cookie. Signed-off-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/20240115205514.68364-5-kuniyu@amazon.com Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov

tcp: Factorise cookie-dependent fields initialisation in cookie_v[46]_check()

2023-11-30T04:16:38+00:00

We will support arbitrary SYN Cookie with BPF, and then kfunc at TC will preallocate reqsk and initialise some fields that should not be overwritten later by cookie_v[46]_check(). To simplify the flow in cookie_v[46]_check(), we move such fields' initialisation to cookie_tcp_reqsk_alloc() and factorise non-BPF SYN Cookie handling into cookie_tcp_check(), where we validate the cookie and allocate reqsk, as done by kfunc later. Note that we set ireq->ecn_ok in two steps, the latter of which will be shared by the BPF case. As cookie_ecn_ok() is one-liner, now it's inlined. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20231129022924.96156-9-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

tcp: Factorise cookie-independent fields initialisation in cookie_v[46]_check().

2023-11-30T04:16:34+00:00

We will support arbitrary SYN Cookie with BPF, and then some reqsk fields are initialised in kfunc, and others are done in cookie_v[46]_check(). This patch factorises the common part as cookie_tcp_reqsk_init() and calls it in cookie_tcp_reqsk_alloc() to minimise the discrepancy between cookie_v[46]_check(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20231129022924.96156-8-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

tcp: Move TCP-AO bits from cookie_v[46]_check() to tcp_ao_syncookie().

2023-11-30T04:16:28+00:00

We initialise treq->af_specific in cookie_tcp_reqsk_alloc() so that we can look up a key later in tcp_create_openreq_child(). Initially, that change was added for MD5 by commit ba5a4fdd63ae ("tcp: make sure treq->af_specific is initialized"), but it has not been used since commit d0f2b7a9ca0a ("tcp: Disable header prediction for MD5 flow."). Now, treq->af_specific is used only by TCP-AO, so, we can move that initialisation into tcp_ao_syncookie(). In addition to that, l3index in cookie_v[46]_check() is only used for tcp_ao_syncookie(), so let's move it as well. While at it, we move down tcp_ao_syncookie() in cookie_v4_check() so that it will be called after security_inet_conn_request() to make functions order consistent with cookie_v6_check(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20231129022924.96156-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

tcp: Don't initialise tp->tsoffset in tcp_get_cookie_sock().

2023-11-30T04:16:23+00:00

When we create a full socket from SYN Cookie, we initialise tcp_sk(sk)->tsoffset redundantly in tcp_get_cookie_sock() as the field is inherited from tcp_rsk(req)->ts_off. cookie_v[46]_check |- treq->ts_off = 0 `- tcp_get_cookie_sock |- tcp_v[46]_syn_recv_sock | `- tcp_create_openreq_child | `- newtp->tsoffset = treq->ts_off `- tcp_sk(child)->tsoffset = tsoff Let's initialise tcp_rsk(req)->ts_off with the correct offset and remove the second initialisation of tcp_sk(sk)->tsoffset. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20231129022924.96156-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski