From 9fce92f050f448a0d1ddd9083ef967d9930f1e52 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 14 Nov 2023 00:16:13 +0100 Subject: mptcp: deal with large GSO size After the blamed commit below, the TCP sockets (and the MPTCP subflows) can build egress packets larger than 64K. That exceeds the maximum DSS data size, the length being misrepresent on the wire and the stream being corrupted, as later observed on the receiver: WARNING: CPU: 0 PID: 9696 at net/mptcp/protocol.c:705 __mptcp_move_skbs_from_subflow+0x2604/0x26e0 CPU: 0 PID: 9696 Comm: syz-executor.7 Not tainted 6.6.0-rc5-gcd8bdf563d46 #45 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. RIP: 0010:__mptcp_move_skbs_from_subflow+0x2604/0x26e0 net/mptcp/protocol.c:705 RSP: 0018:ffffc90000006e80 EFLAGS: 00010246 RAX: ffffffff83e9f674 RBX: ffff88802f45d870 RCX: ffff888102ad0000 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. RDX: 0000000080000303 RSI: 0000000000013908 RDI: 0000000000003908 RBP: ffffc90000007110 R08: ffffffff83e9e078 R09: 1ffff1100e548c8a R10: dffffc0000000000 R11: ffffed100e548c8b R12: 0000000000013908 R13: dffffc0000000000 R14: 0000000000003908 R15: 000000000031cf29 FS: 00007f239c47e700(0000) GS:ffff88811b200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f239c45cd78 CR3: 000000006a66c006 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 PKRU: 55555554 Call Trace: mptcp_data_ready+0x263/0xac0 net/mptcp/protocol.c:819 subflow_data_ready+0x268/0x6d0 net/mptcp/subflow.c:1409 tcp_data_queue+0x21a1/0x7a60 net/ipv4/tcp_input.c:5151 tcp_rcv_established+0x950/0x1d90 net/ipv4/tcp_input.c:6098 tcp_v6_do_rcv+0x554/0x12f0 net/ipv6/tcp_ipv6.c:1483 tcp_v6_rcv+0x2e26/0x3810 net/ipv6/tcp_ipv6.c:1749 ip6_protocol_deliver_rcu+0xd6b/0x1ae0 net/ipv6/ip6_input.c:438 ip6_input+0x1c5/0x470 net/ipv6/ip6_input.c:483 ipv6_rcv+0xef/0x2c0 include/linux/netfilter.h:304 __netif_receive_skb+0x1ea/0x6a0 net/core/dev.c:5532 process_backlog+0x353/0x660 net/core/dev.c:5974 __napi_poll+0xc6/0x5a0 net/core/dev.c:6536 net_rx_action+0x6a0/0xfd0 net/core/dev.c:6603 __do_softirq+0x184/0x524 kernel/softirq.c:553 do_softirq+0xdd/0x130 kernel/softirq.c:454 Address the issue explicitly bounding the maximum GSO size to what MPTCP actually allows. Reported-by: Christoph Paasch Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/450 Fixes: 7c4e983c4f3c ("net: allow gso_max_size to exceed 65536") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-1-7b9cd6a7b7f4@kernel.org Signed-off-by: Jakub Kicinski --- net/mptcp/protocol.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index a0b8356cd8c5..66e947054945 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1230,6 +1230,8 @@ static void mptcp_update_infinite_map(struct mptcp_sock *msk, mptcp_do_fallback(ssk); } +#define MPTCP_MAX_GSO_SIZE (GSO_LEGACY_MAX_SIZE - (MAX_TCP_HEADER + 1)) + static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, struct mptcp_data_frag *dfrag, struct mptcp_sendmsg_info *info) @@ -1256,6 +1258,8 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, return -EAGAIN; /* compute send limit */ + if (unlikely(ssk->sk_gso_max_size > MPTCP_MAX_GSO_SIZE)) + ssk->sk_gso_max_size = MPTCP_MAX_GSO_SIZE; info->mss_now = tcp_send_mss(ssk, &info->size_goal, info->flags); copy = info->size_goal; -- cgit v1.2.3 From d109a7767273d1706b541c22b83a0323823dfde4 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 14 Nov 2023 00:16:14 +0100 Subject: mptcp: fix possible NULL pointer dereference on close After the blamed commit below, the MPTCP release callback can dereference the first subflow pointer via __mptcp_set_connected() and send buffer auto-tuning. Such pointer is always expected to be valid, except at socket destruction time, when the first subflow is deleted and the pointer zeroed. If the connect event is handled by the release callback while the msk socket is finally released, MPTCP hits the following splat: general protection fault, probably for non-canonical address 0xdffffc00000000f2: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000790-0x0000000000000797] CPU: 1 PID: 26719 Comm: syz-executor.2 Not tainted 6.6.0-syzkaller-10102-gff269e2cd5ad #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 RIP: 0010:mptcp_subflow_ctx net/mptcp/protocol.h:542 [inline] RIP: 0010:__mptcp_propagate_sndbuf net/mptcp/protocol.h:813 [inline] RIP: 0010:__mptcp_set_connected+0x57/0x3e0 net/mptcp/subflow.c:424 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8a62323c RDX: 00000000000000f2 RSI: ffffffff8a630116 RDI: 0000000000000790 RBP: ffff88803334b100 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000034 R12: ffff88803334b198 R13: ffff888054f0b018 R14: 0000000000000000 R15: ffff88803334b100 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbcb4f75198 CR3: 000000006afb5000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mptcp_release_cb+0xa2c/0xc40 net/mptcp/protocol.c:3405 release_sock+0xba/0x1f0 net/core/sock.c:3537 mptcp_close+0x32/0xf0 net/mptcp/protocol.c:3084 inet_release+0x132/0x270 net/ipv4/af_inet.c:433 inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:485 __sock_release+0xae/0x260 net/socket.c:659 sock_close+0x1c/0x20 net/socket.c:1419 __fput+0x270/0xbb0 fs/file_table.c:394 task_work_run+0x14d/0x240 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa92/0x2a20 kernel/exit.c:876 do_group_exit+0xd4/0x2a0 kernel/exit.c:1026 get_signal+0x23ba/0x2790 kernel/signal.c:2900 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7fb515e7cae9 Code: Unable to access opcode bytes at 0x7fb515e7cabf. RSP: 002b:00007fb516c560c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 000000000000003c RBX: 00007fb515f9c120 RCX: 00007fb515e7cae9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000006 RBP: 00007fb515ec847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fb515f9c120 R15: 00007ffc631eb968 To avoid sparkling unneeded conditionals, address the issue explicitly checking msk->first only in the critical place. Fixes: 8005184fd1ca ("mptcp: refactor sndbuf auto-tuning") Cc: stable@vger.kernel.org Reported-by: Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/454 Reported-by: Eric Dumazet Closes: https://lore.kernel.org/netdev/CANn89iLZUA6S2a=K8GObnS62KK6Jt4B7PsAs7meMFooM8xaTgw@mail.gmail.com/ Signed-off-by: Paolo Abeni Reviewed-by: Eric Dumazet Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-2-7b9cd6a7b7f4@kernel.org Signed-off-by: Jakub Kicinski --- net/mptcp/protocol.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 66e947054945..bc81ea53a049 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3402,10 +3402,11 @@ static void mptcp_release_cb(struct sock *sk) if (__test_and_clear_bit(MPTCP_CLEAN_UNA, &msk->cb_flags)) __mptcp_clean_una_wakeup(sk); if (unlikely(msk->cb_flags)) { - /* be sure to set the current sk state before tacking actions - * depending on sk_state, that is processing MPTCP_ERROR_REPORT + /* be sure to set the current sk state before taking actions + * depending on sk_state (MPTCP_ERROR_REPORT) + * On sk release avoid actions depending on the first subflow */ - if (__test_and_clear_bit(MPTCP_CONNECTED, &msk->cb_flags)) + if (__test_and_clear_bit(MPTCP_CONNECTED, &msk->cb_flags) && msk->first) __mptcp_set_connected(sk); if (__test_and_clear_bit(MPTCP_ERROR_REPORT, &msk->cb_flags)) __mptcp_error_report(sk); -- cgit v1.2.3 From 8df220b29282e8b450ea57be62e1eccd4996837c Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Tue, 14 Nov 2023 00:16:15 +0100 Subject: mptcp: add validity check for sending RM_ADDR This patch adds the validity check for sending RM_ADDRs for userspace PM in mptcp_pm_remove_addrs(), only send a RM_ADDR when the address is in the anno_list or conn_list. Fixes: 8b1c94da1e48 ("mptcp: only send RM_ADDR in nl_cmd_remove") Cc: stable@vger.kernel.org Signed-off-by: Geliang Tang Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-3-7b9cd6a7b7f4@kernel.org Signed-off-by: Jakub Kicinski --- net/mptcp/pm_netlink.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 1529ec358815..bf4d96f6f99a 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1515,8 +1515,9 @@ void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list) struct mptcp_pm_addr_entry *entry; list_for_each_entry(entry, rm_list, list) { - remove_anno_list_by_saddr(msk, &entry->addr); - if (alist.nr < MPTCP_RM_IDS_MAX) + if ((remove_anno_list_by_saddr(msk, &entry->addr) || + lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) && + alist.nr < MPTCP_RM_IDS_MAX) alist.ids[alist.nr++] = entry->addr.id; } -- cgit v1.2.3 From 7679d34f97b7a09fd565f5729f79fd61b7c55329 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 14 Nov 2023 00:16:16 +0100 Subject: mptcp: fix setsockopt(IP_TOS) subflow locking The MPTCP implementation of the IP_TOS socket option uses the lockless variant of the TOS manipulation helper and does not hold such lock at the helper invocation time. Add the required locking. Fixes: ffcacff87cd6 ("mptcp: Support for IP_TOS for MPTCP setsockopt()") Cc: stable@vger.kernel.org Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/457 Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-4-7b9cd6a7b7f4@kernel.org Signed-off-by: Jakub Kicinski --- net/mptcp/sockopt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 77f5e8932abf..353680733700 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -738,8 +738,11 @@ static int mptcp_setsockopt_v4_set_tos(struct mptcp_sock *msk, int optname, val = READ_ONCE(inet_sk(sk)->tos); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + bool slow; + slow = lock_sock_fast(ssk); __ip_sock_set_tos(ssk, val); + unlock_sock_fast(ssk, slow); } release_sock(sk); -- cgit v1.2.3 From 7cefbe5e1dacc7236caa77e9d072423f21422fe2 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 14 Nov 2023 00:16:17 +0100 Subject: selftests: mptcp: fix fastclose with csum failure Running the mp_join selftest manually with the following command line: ./mptcp_join.sh -z -C leads to some failures: 002 fastclose server test # ... rtx [fail] got 1 MP_RST[s] TX expected 0 # ... rstrx [fail] got 1 MP_RST[s] RX expected 0 The problem is really in the wrong expectations for the RST checks implied by the csum validation. Note that the same check is repeated explicitly in the same test-case, with the correct expectation and pass successfully. Address the issue explicitly setting the correct expectation for the failing checks. Reported-by: Xiumei Mu Fixes: 6bf41020b72b ("selftests: mptcp: update and extend fastclose test-cases") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts Signed-off-by: Matthieu Baerts Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-5-7b9cd6a7b7f4@kernel.org Signed-off-by: Jakub Kicinski --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index 75a2438efdf3..3c94f2f194d6 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -3240,7 +3240,7 @@ fastclose_tests() if reset_check_counter "fastclose server test" "MPTcpExtMPFastcloseRx"; then test_linkfail=1024 fastclose=server \ run_tests $ns1 $ns2 10.0.1.1 - chk_join_nr 0 0 0 + chk_join_nr 0 0 0 0 0 0 1 chk_fclose_nr 1 1 invert chk_rst_nr 1 1 fi -- cgit v1.2.3