kernel.git/net/dccp/ipv6.c, branch linux-4.14.y

dccp/tcp: Call security_inet_conn_request() after setting IPv6 addresses.

2023-11-20T09:27:35Z

[ Upstream commit 23be1e0e2a83a8543214d2599a31d9a2185a796b ] Initially, commit 4237c75c0a35 ("[MLSXFRM]: Auto-labeling of child sockets") introduced security_inet_conn_request() in some functions where reqsk is allocated. The hook is added just after the allocation, so reqsk's IPv6 remote address was not initialised then. However, SELinux/Smack started to read it in netlbl_req_setattr() after commit e1adea927080 ("calipso: Allow request sockets to be relabelled by the lsm."). Commit 284904aa7946 ("lsm: Relocate the IPv4 security_inet_conn_request() hooks") fixed that kind of issue only in TCPv4 because IPv6 labeling was not supported at that time. Finally, the same issue was introduced again in IPv6. Let's apply the same fix on DCCPv6 and TCPv6. Fixes: e1adea927080 ("calipso: Allow request sockets to be relabelled by the lsm.") Signed-off-by: Kuniyuki Iwashima Acked-by: Paul Moore Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

dccp: fix dccp_v4_err()/dccp_v6_err() again

2023-10-10T19:43:38Z

[ Upstream commit 6af289746a636f71f4c0535a9801774118486c7a ] dh->dccph_x is the 9th byte (offset 8) in "struct dccp_hdr", not in the "byte 7" as Jann claimed. We need to make sure the ICMP messages are big enough, using more standard ways (no more assumptions). syzbot reported: BUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2667 [inline] BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2681 [inline] BUG: KMSAN: uninit-value in dccp_v6_err+0x426/0x1aa0 net/dccp/ipv6.c:94 pskb_may_pull_reason include/linux/skbuff.h:2667 [inline] pskb_may_pull include/linux/skbuff.h:2681 [inline] dccp_v6_err+0x426/0x1aa0 net/dccp/ipv6.c:94 icmpv6_notify+0x4c7/0x880 net/ipv6/icmp.c:867 icmpv6_rcv+0x19d5/0x30d0 ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492 ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:304 [inline] ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5782 tun_rx_batched+0x83b/0x920 tun_get_user+0x564c/0x6940 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x15c0 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x318/0x740 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6313 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2795 tun_alloc_skb drivers/net/tun.c:1531 [inline] tun_get_user+0x23cf/0x6940 drivers/net/tun.c:1846 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x15c0 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd CPU: 0 PID: 4995 Comm: syz-executor153 Not tainted 6.6.0-rc1-syzkaller-00014-ga747acc0b752 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Fixes: 977ad86c2a1b ("dccp: Fix out of bounds access in DCCP error handler") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Jann Horn Reviewed-by: Jann Horn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

dccp: Fix out of bounds access in DCCP error handler

2023-09-23T08:47:00Z

commit 977ad86c2a1bcaf58f01ab98df5cc145083c489c upstream. There was a previous attempt to fix an out-of-bounds access in the DCCP error handlers, but that fix assumed that the error handlers only want to access the first 8 bytes of the DCCP header. Actually, they also look at the DCCP sequence number, which is stored beyond 8 bytes, so an explicit pskb_may_pull() is required. Fixes: 6706a97fec96 ("dccp: fix out of bound access in dccp_v4_err()") Fixes: 1aa9d1a0e7ee ("ipv6: dccp: fix out of bound access in dccp_v6_err()") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

dccp: Call inet6_destroy_sock() via sk->sk_destruct().

2023-04-26T09:18:57Z

commit 1651951ebea54970e0bda60c638fc2eee7a6218f upstream. After commit d38afeec26ed ("tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct()."), we call inet6_destroy_sock() in sk->sk_destruct() by setting inet6_sock_destruct() to it to make sure we do not leak inet6-specific resources. DCCP sets its own sk->sk_destruct() in the dccp_init_sock(), and DCCPv6 socket shares it by calling the same init function via dccp_v6_init_sock(). To call inet6_sock_destruct() from DCCPv6 sk->sk_destruct(), we export it and set dccp_v6_sk_destruct() in the init function. Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Ziyang Xuan Signed-off-by: Greg Kroah-Hartman

dccp/tcp: Avoid negative sk_forward_alloc by ipv6_pinfo.pktoptions.

2023-02-22T11:46:06Z

commit ca43ccf41224b023fc290073d5603a755fd12eed upstream. Eric Dumazet pointed out [0] that when we call skb_set_owner_r() for ipv6_pinfo.pktoptions, sk_rmem_schedule() has not been called, resulting in a negative sk_forward_alloc. We add a new helper which clones a skb and sets its owner only when sk_rmem_schedule() succeeds. Note that we move skb_set_owner_r() forward in (dccp|tcp)_v6_do_rcv() because tcp_send_synack() can make sk_forward_alloc negative before ipv6_opt_accepted() in the crossed SYN-ACK or self-connect() cases. [0]: https://lore.kernel.org/netdev/CANn89iK9oc20Jdi_41jb9URdF210r7d1Y-+uypbMSbOfY6jqrg@mail.gmail.com/ Fixes: 323fbd0edf3f ("net: dccp: Add handling of IPV6_PKTOPTIONS to dccp_v6_do_rcv()") Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

dccp/tcp: Reset saddr on failure after inet6?_hash_connect().

2022-12-08T10:16:30Z

[ Upstream commit 77934dc6db0d2b111a8f2759e9ad2fb67f5cffa5 ] When connect() is called on a socket bound to the wildcard address, we change the socket's saddr to a local address. If the socket fails to connect() to the destination, we have to reset the saddr. However, when an error occurs after inet_hash6?_connect() in (dccp|tcp)_v[46]_conect(), we forget to reset saddr and leave the socket bound to the address. From the user's point of view, whether saddr is reset or not varies with errno. Let's fix this inconsistent behaviour. Note that after this patch, the repro [0] will trigger the WARN_ON() in inet_csk_get_port() again, but this patch is not buggy and rather fixes a bug papering over the bhash2's bug for which we need another fix. For the record, the repro causes -EADDRNOTAVAIL in inet_hash6_connect() by this sequence: s1 = socket() s1.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) s1.bind(('127.0.0.1', 10000)) s1.sendto(b'hello', MSG_FASTOPEN, (('127.0.0.1', 10000))) # or s1.connect(('127.0.0.1', 10000)) s2 = socket() s2.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) s2.bind(('0.0.0.0', 10000)) s2.connect(('127.0.0.1', 10000)) # -EADDRNOTAVAIL s2.listen(32) # WARN_ON(inet_csk(sk)->icsk_bind2_hash != tb2); [0]: https://syzkaller.appspot.com/bug?extid=015d756bbd1f8b5c8f09 Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Fixes: 7c657876b63c ("[DCCP]: Initial implementation") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Acked-by: Joanne Koong Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

tcp: fix race condition when creating child sockets from syncookies

2022-04-27T11:15:29Z

[ Upstream commit 01770a166165738a6e05c3d911fb4609cc4eb416 ] When the TCP stack is in SYN flood mode, the server child socket is created from the SYN cookie received in a TCP packet with the ACK flag set. The child socket is created when the server receives the first TCP packet with a valid SYN cookie from the client. Usually, this packet corresponds to the final step of the TCP 3-way handshake, the ACK packet. But is also possible to receive a valid SYN cookie from the first TCP data packet sent by the client, and thus create a child socket from that SYN cookie. Since a client socket is ready to send data as soon as it receives the SYN+ACK packet from the server, the client can send the ACK packet (sent by the TCP stack code), and the first data packet (sent by the userspace program) almost at the same time, and thus the server will equally receive the two TCP packets with valid SYN cookies almost at the same instant. When such event happens, the TCP stack code has a race condition that occurs between the momement a lookup is done to the established connections hashtable to check for the existence of a connection for the same client, and the moment that the child socket is added to the established connections hashtable. As a consequence, this race condition can lead to a situation where we add two child sockets to the established connections hashtable and deliver two sockets to the userspace program to the same client. This patch fixes the race condition by checking if an existing child socket exists for the same client when we are adding the second child socket to the established connections socket. If an existing child socket exists, we drop the packet and discard the second child socket to the same client. Signed-off-by: Ricardo Dias Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20201120111133.GA67501@rdias-suse-pc.lan Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ipv6: weaken the v4mapped source check

2021-04-07T10:47:00Z

[ Upstream commit dcc32f4f183ab8479041b23a1525d48233df1d43 ] This reverts commit 6af1799aaf3f1bc8defedddfa00df3192445bbf3. Commit 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped source address") introduced an input check against v4mapped addresses. Use of such addresses on the wire is indeed questionable and not allowed on public Internet. As the commit pointed out https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02 lists potential issues. Unfortunately there are applications which use v4mapped addresses, and breaking them is a clear regression. For example v4mapped addresses (or any semi-valid addresses, really) may be used for uni-direction event streams or packet export. Since the issue which sparked the addition of the check was with TCP and request_socks in particular push the check down to TCPv6 and DCCP. This restores the ability to receive UDPv6 packets with v4mapped address as the source. Keep using the IPSTATS_MIB_INHDRERRORS statistic to minimize the user-visible changes. Fixes: 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped source address") Reported-by: Sunyi Shao Signed-off-by: Jakub Kicinski Acked-by: Mat Martineau Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: ipv6: add net argument to ip6_dst_lookup_flow

2020-05-20T06:17:02Z

commit c4e85f73afb6384123e5ef1bba3315b2e3ad031e upstream. This will be used in the conversion of ipv6_stub to ip6_dst_lookup_flow, as some modules currently pass a net argument without a socket to ip6_dst_lookup. This is equivalent to commit 343d60aada5a ("ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument"). Signed-off-by: Sabrina Dubroca Signed-off-by: David S. Miller [bwh: Backported to 4.14: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

dccp: do not use ipv6 header for ipv4 flow

2019-04-03T04:25:08Z

[ Upstream commit e0aa67709f89d08c8d8e5bdd9e0b649df61d0090 ] When a dual stack dccp listener accepts an ipv4 flow, it should not attempt to use an ipv6 header or inet6_iif() helper. Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman