From 7212303268918b9a203aebeacfdbd83b5e87b20d Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 11 Apr 2018 14:36:28 -0700 Subject: tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets syzbot/KMSAN reported an uninit-value in tcp_parse_options() [1] I believe this was caused by a TCP_MD5SIG being set on live flow. This is highly unexpected, since TCP option space is limited. For instance, presence of TCP MD5 option automatically disables TCP TimeStamp option at SYN/SYNACK time, which we can not do once flow has been established. Really, adding/deleting an MD5 key only makes sense on sockets in CLOSE or LISTEN state. [1] BUG: KMSAN: uninit-value in tcp_parse_options+0xd74/0x1a30 net/ipv4/tcp_input.c:3720 CPU: 1 PID: 6177 Comm: syzkaller192004 Not tainted 4.16.0+ #83 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 tcp_parse_options+0xd74/0x1a30 net/ipv4/tcp_input.c:3720 tcp_fast_parse_options net/ipv4/tcp_input.c:3858 [inline] tcp_validate_incoming+0x4f1/0x2790 net/ipv4/tcp_input.c:5184 tcp_rcv_established+0xf60/0x2bb0 net/ipv4/tcp_input.c:5453 tcp_v4_do_rcv+0x6cd/0xd90 net/ipv4/tcp_ipv4.c:1469 sk_backlog_rcv include/net/sock.h:908 [inline] __release_sock+0x2d6/0x680 net/core/sock.c:2271 release_sock+0x97/0x2a0 net/core/sock.c:2786 tcp_sendmsg+0xd6/0x100 net/ipv4/tcp.c:1464 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] SYSC_sendto+0x6c3/0x7e0 net/socket.c:1747 SyS_sendto+0x8a/0xb0 net/socket.c:1715 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x448fe9 RSP: 002b:00007fd472c64d38 EFLAGS: 00000216 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000006e5a30 RCX: 0000000000448fe9 RDX: 000000000000029f RSI: 0000000020a88f88 RDI: 0000000000000004 RBP: 00000000006e5a34 R08: 0000000020e68000 R09: 0000000000000010 R10: 00000000200007fd R11: 0000000000000216 R12: 0000000000000000 R13: 00007fff074899ef R14: 00007fd472c659c0 R15: 0000000000000009 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc_node mm/slub.c:2737 [inline] __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:984 [inline] tcp_send_ack+0x18c/0x910 net/ipv4/tcp_output.c:3624 __tcp_ack_snd_check net/ipv4/tcp_input.c:5040 [inline] tcp_ack_snd_check net/ipv4/tcp_input.c:5053 [inline] tcp_rcv_established+0x2103/0x2bb0 net/ipv4/tcp_input.c:5469 tcp_v4_do_rcv+0x6cd/0xd90 net/ipv4/tcp_ipv4.c:1469 sk_backlog_rcv include/net/sock.h:908 [inline] __release_sock+0x2d6/0x680 net/core/sock.c:2271 release_sock+0x97/0x2a0 net/core/sock.c:2786 tcp_sendmsg+0xd6/0x100 net/ipv4/tcp.c:1464 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] SYSC_sendto+0x6c3/0x7e0 net/socket.c:1747 SyS_sendto+0x8a/0xb0 net/socket.c:1715 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Fixes: cfb6eeb4c860 ("[TCP]: MD5 Signature Option (RFC2385) support.") Signed-off-by: Eric Dumazet Reported-by: syzbot Acked-by: Yuchung Cheng Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index bccc4c270087..4fa3f812b9ff 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2813,8 +2813,10 @@ static int do_tcp_setsockopt(struct sock *sk, int level, #ifdef CONFIG_TCP_MD5SIG case TCP_MD5SIG: case TCP_MD5SIG_EXT: - /* Read the IP->Key mappings from userspace */ - err = tp->af_specific->md5_parse(sk, optname, optval, optlen); + if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) + err = tp->af_specific->md5_parse(sk, optname, optval, optlen); + else + err = -EINVAL; break; #endif case TCP_USER_TIMEOUT: -- cgit v1.2.3 From bffd168c3fc5cc7d2bad4c668fa90e7a9010db4b Mon Sep 17 00:00:00 2001 From: Soheil Hassas Yeganeh Date: Sat, 14 Apr 2018 20:44:46 -0400 Subject: tcp: clear tp->packets_out when purging write queue Clear tp->packets_out when purging the write queue, otherwise tcp_rearm_rto() mistakenly assumes TCP write queue is not empty. This results in NULL pointer dereference. Also, remove the redundant `tp->packets_out = 0` from tcp_disconnect(), since tcp_disconnect() calls tcp_write_queue_purge(). Fixes: a27fd7a8ed38 (tcp: purge write queue upon RST) Reported-by: Subash Abhinov Kasiviswanathan Reported-by: Sami Farin Tested-by: Sami Farin Signed-off-by: Eric Dumazet Signed-off-by: Soheil Hassas Yeganeh Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 4fa3f812b9ff..9ce1c726185e 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2368,6 +2368,7 @@ void tcp_write_queue_purge(struct sock *sk) INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue); sk_mem_reclaim(sk); tcp_clear_all_retrans_hints(tcp_sk(sk)); + tcp_sk(sk)->packets_out = 0; } int tcp_disconnect(struct sock *sk, int flags) @@ -2417,7 +2418,6 @@ int tcp_disconnect(struct sock *sk, int flags) icsk->icsk_backoff = 0; tp->snd_cwnd = 2; icsk->icsk_probes_out = 0; - tp->packets_out = 0; tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; tp->snd_cwnd_cnt = 0; tp->window_clamp = 0; -- cgit v1.2.3 From 9783ccd0f2507cbe3c5ff1cb84bf6ae3a512d17d Mon Sep 17 00:00:00 2001 From: Gao Feng Date: Mon, 16 Apr 2018 10:16:45 +0800 Subject: net: Fix one possible memleak in ip_setup_cork It would allocate memory in this function when the cork->opt is NULL. But the memory isn't freed if failed in the latter rt check, and return error directly. It causes the memleak if its caller is ip_make_skb which also doesn't free the cork->opt when meet a error. Now move the rt check ahead to avoid the memleak. Signed-off-by: Gao Feng Signed-off-by: David S. Miller --- net/ipv4/ip_output.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 4c11b810a447..83c73bab2c3d 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1109,6 +1109,10 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, struct ip_options_rcu *opt; struct rtable *rt; + rt = *rtp; + if (unlikely(!rt)) + return -EFAULT; + /* * setup for corking. */ @@ -1124,9 +1128,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, cork->flags |= IPCORK_OPT; cork->addr = ipc->addr; } - rt = *rtp; - if (unlikely(!rt)) - return -EFAULT; + /* * We steal reference to this route, caller should not release it */ -- cgit v1.2.3