--- /dev/null
+From c86b000782daba926c627d2fa00c3f60a75e7472 Mon Sep 17 00:00:00 2001
+From: Paolo Abeni <pabeni@redhat.com>
+Date: Thu, 23 Jan 2025 19:05:54 +0100
+Subject: mptcp: consolidate suboption status
+
+From: Paolo Abeni <pabeni@redhat.com>
+
+commit c86b000782daba926c627d2fa00c3f60a75e7472 upstream.
+
+MPTCP maintains the received sub-options status is the bitmask carrying
+the received suboptions and in several bitfields carrying per suboption
+additional info.
+
+Zeroing the bitmask before parsing is not enough to ensure a consistent
+status, and the MPTCP code has to additionally clear some bitfiled
+depending on the actually parsed suboption.
+
+The above schema is fragile, and syzbot managed to trigger a path where
+a relevant bitfield is not cleared/initialized:
+
+ BUG: KMSAN: uninit-value in __mptcp_expand_seq net/mptcp/options.c:1030 [inline]
+ BUG: KMSAN: uninit-value in mptcp_expand_seq net/mptcp/protocol.h:864 [inline]
+ BUG: KMSAN: uninit-value in ack_update_msk net/mptcp/options.c:1060 [inline]
+ BUG: KMSAN: uninit-value in mptcp_incoming_options+0x2036/0x3d30 net/mptcp/options.c:1209
+ __mptcp_expand_seq net/mptcp/options.c:1030 [inline]
+ mptcp_expand_seq net/mptcp/protocol.h:864 [inline]
+ ack_update_msk net/mptcp/options.c:1060 [inline]
+ mptcp_incoming_options+0x2036/0x3d30 net/mptcp/options.c:1209
+ tcp_data_queue+0xb4/0x7be0 net/ipv4/tcp_input.c:5233
+ tcp_rcv_established+0x1061/0x2510 net/ipv4/tcp_input.c:6264
+ tcp_v4_do_rcv+0x7f3/0x11a0 net/ipv4/tcp_ipv4.c:1916
+ tcp_v4_rcv+0x51df/0x5750 net/ipv4/tcp_ipv4.c:2351
+ ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205
+ ip_local_deliver_finish+0x336/0x500 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:447
+ NF_HOOK include/linux/netfilter.h:314 [inline]
+ ip_rcv+0xcd/0x380 net/ipv4/ip_input.c:567
+ __netif_receive_skb_one_core net/core/dev.c:5704 [inline]
+ __netif_receive_skb+0x319/0xa00 net/core/dev.c:5817
+ process_backlog+0x4ad/0xa50 net/core/dev.c:6149
+ __napi_poll+0xe7/0x980 net/core/dev.c:6902
+ napi_poll net/core/dev.c:6971 [inline]
+ net_rx_action+0xa5a/0x19b0 net/core/dev.c:7093
+ handle_softirqs+0x1a0/0x7c0 kernel/softirq.c:561
+ __do_softirq+0x14/0x1a kernel/softirq.c:595
+ do_softirq+0x9a/0x100 kernel/softirq.c:462
+ __local_bh_enable_ip+0x9f/0xb0 kernel/softirq.c:389
+ local_bh_enable include/linux/bottom_half.h:33 [inline]
+ rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline]
+ __dev_queue_xmit+0x2758/0x57d0 net/core/dev.c:4493
+ dev_queue_xmit include/linux/netdevice.h:3168 [inline]
+ neigh_hh_output include/net/neighbour.h:523 [inline]
+ neigh_output include/net/neighbour.h:537 [inline]
+ ip_finish_output2+0x187c/0x1b70 net/ipv4/ip_output.c:236
+ __ip_finish_output+0x287/0x810
+ ip_finish_output+0x4b/0x600 net/ipv4/ip_output.c:324
+ NF_HOOK_COND include/linux/netfilter.h:303 [inline]
+ ip_output+0x15f/0x3f0 net/ipv4/ip_output.c:434
+ dst_output include/net/dst.h:450 [inline]
+ ip_local_out net/ipv4/ip_output.c:130 [inline]
+ __ip_queue_xmit+0x1f2a/0x20d0 net/ipv4/ip_output.c:536
+ ip_queue_xmit+0x60/0x80 net/ipv4/ip_output.c:550
+ __tcp_transmit_skb+0x3cea/0x4900 net/ipv4/tcp_output.c:1468
+ tcp_transmit_skb net/ipv4/tcp_output.c:1486 [inline]
+ tcp_write_xmit+0x3b90/0x9070 net/ipv4/tcp_output.c:2829
+ __tcp_push_pending_frames+0xc4/0x380 net/ipv4/tcp_output.c:3012
+ tcp_send_fin+0x9f6/0xf50 net/ipv4/tcp_output.c:3618
+ __tcp_close+0x140c/0x1550 net/ipv4/tcp.c:3130
+ __mptcp_close_ssk+0x74e/0x16f0 net/mptcp/protocol.c:2496
+ mptcp_close_ssk+0x26b/0x2c0 net/mptcp/protocol.c:2550
+ mptcp_pm_nl_rm_addr_or_subflow+0x635/0xd10 net/mptcp/pm_netlink.c:889
+ mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:924 [inline]
+ mptcp_pm_flush_addrs_and_subflows net/mptcp/pm_netlink.c:1688 [inline]
+ mptcp_nl_flush_addrs_list net/mptcp/pm_netlink.c:1709 [inline]
+ mptcp_pm_nl_flush_addrs_doit+0xe10/0x1630 net/mptcp/pm_netlink.c:1750
+ genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
+ genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
+ genl_rcv_msg+0x1214/0x12c0 net/netlink/genetlink.c:1210
+ netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2542
+ genl_rcv+0x40/0x60 net/netlink/genetlink.c:1219
+ netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
+ netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1347
+ netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1891
+ sock_sendmsg_nosec net/socket.c:711 [inline]
+ __sock_sendmsg+0x30f/0x380 net/socket.c:726
+ ____sys_sendmsg+0x877/0xb60 net/socket.c:2583
+ ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2637
+ __sys_sendmsg net/socket.c:2669 [inline]
+ __do_sys_sendmsg net/socket.c:2674 [inline]
+ __se_sys_sendmsg net/socket.c:2672 [inline]
+ __x64_sys_sendmsg+0x212/0x3c0 net/socket.c:2672
+ x64_sys_call+0x2ed6/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:47
+ do_syscall_x64 arch/x86/entry/common.c:52 [inline]
+ do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
+ entry_SYSCALL_64_after_hwframe+0x77/0x7f
+
+ Uninit was stored to memory at:
+ mptcp_get_options+0x2c0f/0x2f20 net/mptcp/options.c:397
+ mptcp_incoming_options+0x19a/0x3d30 net/mptcp/options.c:1150
+ tcp_data_queue+0xb4/0x7be0 net/ipv4/tcp_input.c:5233
+ tcp_rcv_established+0x1061/0x2510 net/ipv4/tcp_input.c:6264
+ tcp_v4_do_rcv+0x7f3/0x11a0 net/ipv4/tcp_ipv4.c:1916
+ tcp_v4_rcv+0x51df/0x5750 net/ipv4/tcp_ipv4.c:2351
+ ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205
+ ip_local_deliver_finish+0x336/0x500 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:447
+ NF_HOOK include/linux/netfilter.h:314 [inline]
+ ip_rcv+0xcd/0x380 net/ipv4/ip_input.c:567
+ __netif_receive_skb_one_core net/core/dev.c:5704 [inline]
+ __netif_receive_skb+0x319/0xa00 net/core/dev.c:5817
+ process_backlog+0x4ad/0xa50 net/core/dev.c:6149
+ __napi_poll+0xe7/0x980 net/core/dev.c:6902
+ napi_poll net/core/dev.c:6971 [inline]
+ net_rx_action+0xa5a/0x19b0 net/core/dev.c:7093
+ handle_softirqs+0x1a0/0x7c0 kernel/softirq.c:561
+ __do_softirq+0x14/0x1a kernel/softirq.c:595
+
+ Uninit was stored to memory at:
+ put_unaligned_be32 include/linux/unaligned.h:68 [inline]
+ mptcp_write_options+0x17f9/0x3100 net/mptcp/options.c:1417
+ mptcp_options_write net/ipv4/tcp_output.c:465 [inline]
+ tcp_options_write+0x6d9/0xe90 net/ipv4/tcp_output.c:759
+ __tcp_transmit_skb+0x294b/0x4900 net/ipv4/tcp_output.c:1414
+ tcp_transmit_skb net/ipv4/tcp_output.c:1486 [inline]
+ tcp_write_xmit+0x3b90/0x9070 net/ipv4/tcp_output.c:2829
+ __tcp_push_pending_frames+0xc4/0x380 net/ipv4/tcp_output.c:3012
+ tcp_send_fin+0x9f6/0xf50 net/ipv4/tcp_output.c:3618
+ __tcp_close+0x140c/0x1550 net/ipv4/tcp.c:3130
+ __mptcp_close_ssk+0x74e/0x16f0 net/mptcp/protocol.c:2496
+ mptcp_close_ssk+0x26b/0x2c0 net/mptcp/protocol.c:2550
+ mptcp_pm_nl_rm_addr_or_subflow+0x635/0xd10 net/mptcp/pm_netlink.c:889
+ mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:924 [inline]
+ mptcp_pm_flush_addrs_and_subflows net/mptcp/pm_netlink.c:1688 [inline]
+ mptcp_nl_flush_addrs_list net/mptcp/pm_netlink.c:1709 [inline]
+ mptcp_pm_nl_flush_addrs_doit+0xe10/0x1630 net/mptcp/pm_netlink.c:1750
+ genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
+ genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
+ genl_rcv_msg+0x1214/0x12c0 net/netlink/genetlink.c:1210
+ netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2542
+ genl_rcv+0x40/0x60 net/netlink/genetlink.c:1219
+ netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
+ netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1347
+ netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1891
+ sock_sendmsg_nosec net/socket.c:711 [inline]
+ __sock_sendmsg+0x30f/0x380 net/socket.c:726
+ ____sys_sendmsg+0x877/0xb60 net/socket.c:2583
+ ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2637
+ __sys_sendmsg net/socket.c:2669 [inline]
+ __do_sys_sendmsg net/socket.c:2674 [inline]
+ __se_sys_sendmsg net/socket.c:2672 [inline]
+ __x64_sys_sendmsg+0x212/0x3c0 net/socket.c:2672
+ x64_sys_call+0x2ed6/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:47
+ do_syscall_x64 arch/x86/entry/common.c:52 [inline]
+ do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
+ entry_SYSCALL_64_after_hwframe+0x77/0x7f
+
+ Uninit was stored to memory at:
+ mptcp_pm_add_addr_signal+0x3d7/0x4c0
+ mptcp_established_options_add_addr net/mptcp/options.c:666 [inline]
+ mptcp_established_options+0x1b9b/0x3a00 net/mptcp/options.c:884
+ tcp_established_options+0x2c4/0x7d0 net/ipv4/tcp_output.c:1012
+ __tcp_transmit_skb+0x5b7/0x4900 net/ipv4/tcp_output.c:1333
+ tcp_transmit_skb net/ipv4/tcp_output.c:1486 [inline]
+ tcp_write_xmit+0x3b90/0x9070 net/ipv4/tcp_output.c:2829
+ __tcp_push_pending_frames+0xc4/0x380 net/ipv4/tcp_output.c:3012
+ tcp_send_fin+0x9f6/0xf50 net/ipv4/tcp_output.c:3618
+ __tcp_close+0x140c/0x1550 net/ipv4/tcp.c:3130
+ __mptcp_close_ssk+0x74e/0x16f0 net/mptcp/protocol.c:2496
+ mptcp_close_ssk+0x26b/0x2c0 net/mptcp/protocol.c:2550
+ mptcp_pm_nl_rm_addr_or_subflow+0x635/0xd10 net/mptcp/pm_netlink.c:889
+ mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:924 [inline]
+ mptcp_pm_flush_addrs_and_subflows net/mptcp/pm_netlink.c:1688 [inline]
+ mptcp_nl_flush_addrs_list net/mptcp/pm_netlink.c:1709 [inline]
+ mptcp_pm_nl_flush_addrs_doit+0xe10/0x1630 net/mptcp/pm_netlink.c:1750
+ genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
+ genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
+ genl_rcv_msg+0x1214/0x12c0 net/netlink/genetlink.c:1210
+ netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2542
+ genl_rcv+0x40/0x60 net/netlink/genetlink.c:1219
+ netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
+ netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1347
+ netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1891
+ sock_sendmsg_nosec net/socket.c:711 [inline]
+ __sock_sendmsg+0x30f/0x380 net/socket.c:726
+ ____sys_sendmsg+0x877/0xb60 net/socket.c:2583
+ ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2637
+ __sys_sendmsg net/socket.c:2669 [inline]
+ __do_sys_sendmsg net/socket.c:2674 [inline]
+ __se_sys_sendmsg net/socket.c:2672 [inline]
+ __x64_sys_sendmsg+0x212/0x3c0 net/socket.c:2672
+ x64_sys_call+0x2ed6/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:47
+ do_syscall_x64 arch/x86/entry/common.c:52 [inline]
+ do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
+ entry_SYSCALL_64_after_hwframe+0x77/0x7f
+
+ Uninit was stored to memory at:
+ mptcp_pm_add_addr_received+0x95f/0xdd0 net/mptcp/pm.c:235
+ mptcp_incoming_options+0x2983/0x3d30 net/mptcp/options.c:1169
+ tcp_data_queue+0xb4/0x7be0 net/ipv4/tcp_input.c:5233
+ tcp_rcv_state_process+0x2a38/0x49d0 net/ipv4/tcp_input.c:6972
+ tcp_v4_do_rcv+0xbf9/0x11a0 net/ipv4/tcp_ipv4.c:1939
+ tcp_v4_rcv+0x51df/0x5750 net/ipv4/tcp_ipv4.c:2351
+ ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205
+ ip_local_deliver_finish+0x336/0x500 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:447
+ NF_HOOK include/linux/netfilter.h:314 [inline]
+ ip_rcv+0xcd/0x380 net/ipv4/ip_input.c:567
+ __netif_receive_skb_one_core net/core/dev.c:5704 [inline]
+ __netif_receive_skb+0x319/0xa00 net/core/dev.c:5817
+ process_backlog+0x4ad/0xa50 net/core/dev.c:6149
+ __napi_poll+0xe7/0x980 net/core/dev.c:6902
+ napi_poll net/core/dev.c:6971 [inline]
+ net_rx_action+0xa5a/0x19b0 net/core/dev.c:7093
+ handle_softirqs+0x1a0/0x7c0 kernel/softirq.c:561
+ __do_softirq+0x14/0x1a kernel/softirq.c:595
+
+ Local variable mp_opt created at:
+ mptcp_incoming_options+0x119/0x3d30 net/mptcp/options.c:1127
+ tcp_data_queue+0xb4/0x7be0 net/ipv4/tcp_input.c:5233
+
+The current schema is too fragile; address the issue grouping all the
+state-related data together and clearing the whole group instead of
+just the bitmask. This also cleans-up the code a bit, as there is no
+need to individually clear "random" bitfield in a couple of places
+any more.
+
+Fixes: 84dfe3677a6f ("mptcp: send out dedicated ADD_ADDR packet")
+Cc: stable@vger.kernel.org
+Reported-by: syzbot+23728c2df58b3bd175ad@syzkaller.appspotmail.com
+Closes: https://lore.kernel.org/6786ac51.050a0220.216c54.00a7.GAE@google.com
+Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/541
+Signed-off-by: Paolo Abeni <pabeni@redhat.com>
+Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
+Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
+Link: https://patch.msgid.link/20250123-net-mptcp-syzbot-issues-v1-1-af73258a726f@kernel.org
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/mptcp/options.c | 13 +++++--------
+ net/mptcp/protocol.h | 30 ++++++++++++++++--------------
+ 2 files changed, 21 insertions(+), 22 deletions(-)
+
+--- a/net/mptcp/options.c
++++ b/net/mptcp/options.c
+@@ -103,7 +103,6 @@ static void mptcp_parse_option(const str
+ mp_opt->suboptions |= OPTION_MPTCP_DSS;
+ mp_opt->use_map = 1;
+ mp_opt->mpc_map = 1;
+- mp_opt->use_ack = 0;
+ mp_opt->data_len = get_unaligned_be16(ptr);
+ ptr += 2;
+ }
+@@ -152,11 +151,6 @@ static void mptcp_parse_option(const str
+ pr_debug("DSS\n");
+ ptr++;
+
+- /* we must clear 'mpc_map' be able to detect MP_CAPABLE
+- * map vs DSS map in mptcp_incoming_options(), and reconstruct
+- * map info accordingly
+- */
+- mp_opt->mpc_map = 0;
+ flags = (*ptr++) & MPTCP_DSS_FLAG_MASK;
+ mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0;
+ mp_opt->dsn64 = (flags & MPTCP_DSS_DSN64) != 0;
+@@ -361,8 +355,11 @@ void mptcp_get_options(const struct sk_b
+ const unsigned char *ptr;
+ int length;
+
+- /* initialize option status */
+- mp_opt->suboptions = 0;
++ /* Ensure that casting the whole status to u32 is efficient and safe */
++ BUILD_BUG_ON(sizeof_field(struct mptcp_options_received, status) != sizeof(u32));
++ BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct mptcp_options_received, status),
++ sizeof(u32)));
++ *(u32 *)&mp_opt->status = 0;
+
+ length = (th->doff * 4) - sizeof(struct tcphdr);
+ ptr = (const unsigned char *)(th + 1);
+--- a/net/mptcp/protocol.h
++++ b/net/mptcp/protocol.h
+@@ -139,22 +139,24 @@ struct mptcp_options_received {
+ u32 subflow_seq;
+ u16 data_len;
+ __sum16 csum;
+- u16 suboptions;
++ struct_group(status,
++ u16 suboptions;
++ u16 use_map:1,
++ dsn64:1,
++ data_fin:1,
++ use_ack:1,
++ ack64:1,
++ mpc_map:1,
++ reset_reason:4,
++ reset_transient:1,
++ echo:1,
++ backup:1,
++ deny_join_id0:1,
++ __unused:2;
++ );
++ u8 join_id;
+ u32 token;
+ u32 nonce;
+- u16 use_map:1,
+- dsn64:1,
+- data_fin:1,
+- use_ack:1,
+- ack64:1,
+- mpc_map:1,
+- reset_reason:4,
+- reset_transient:1,
+- echo:1,
+- backup:1,
+- deny_join_id0:1,
+- __unused:2;
+- u8 join_id;
+ u64 thmac;
+ u8 hmac[MPTCPOPT_HMAC_LEN];
+ struct mptcp_addr_info addr;
projects / thirdparty / kernel / stable-queue.git / commitdiff
