kernel/include/net/inet_timewait_sock.h, branch linux-4.1.y

soreuseport: initialise timewait reuseport field

2018-05-23T01:36:40Z

[ Upstream commit 3099a52918937ab86ec47038ad80d377ba16c531 ] syzbot reported an uninit-value in inet_csk_bind_conflict() [1] It turns out we never propagated sk->sk_reuseport into timewait socket. [1] BUG: KMSAN: uninit-value in inet_csk_bind_conflict+0x5f9/0x990 net/ipv4/inet_connection_sock.c:151 CPU: 1 PID: 3589 Comm: syzkaller008242 Not tainted 4.16.0+ #82 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 inet_csk_bind_conflict+0x5f9/0x990 net/ipv4/inet_connection_sock.c:151 inet_csk_get_port+0x1d28/0x1e40 net/ipv4/inet_connection_sock.c:320 inet6_bind+0x121c/0x1820 net/ipv6/af_inet6.c:399 SYSC_bind+0x3f2/0x4b0 net/socket.c:1474 SyS_bind+0x54/0x80 net/socket.c:1460 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x4416e9 RSP: 002b:00007ffce6d15c88 EFLAGS: 00000217 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 0100000000000000 RCX: 00000000004416e9 RDX: 000000000000001c RSI: 0000000020402000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00000000e6d15e08 R09: 00000000e6d15e08 R10: 0000000000000004 R11: 0000000000000217 R12: 0000000000009478 R13: 00000000006cd448 R14: 0000000000000000 R15: 0000000000000000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_save_stack mm/kmsan/kmsan.c:293 [inline] kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521 tcp_time_wait+0xf17/0xf50 net/ipv4/tcp_minisocks.c:283 tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003 tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331 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_close+0x277/0x18f0 net/ipv4/tcp.c:2269 inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435 sock_release net/socket.c:595 [inline] sock_close+0xe0/0x300 net/socket.c:1149 __fput+0x49e/0xa10 fs/file_table.c:209 ____fput+0x37/0x40 fs/file_table.c:243 task_work_run+0x243/0x2c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x10e1/0x38d0 kernel/exit.c:867 do_group_exit+0x1a0/0x360 kernel/exit.c:970 SYSC_exit_group+0x21/0x30 kernel/exit.c:981 SyS_exit_group+0x25/0x30 kernel/exit.c:979 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_save_stack mm/kmsan/kmsan.c:293 [inline] kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521 inet_twsk_alloc+0xaef/0xc00 net/ipv4/inet_timewait_sock.c:182 tcp_time_wait+0xd9/0xf50 net/ipv4/tcp_minisocks.c:258 tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003 tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331 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_close+0x277/0x18f0 net/ipv4/tcp.c:2269 inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435 sock_release net/socket.c:595 [inline] sock_close+0xe0/0x300 net/socket.c:1149 __fput+0x49e/0xa10 fs/file_table.c:209 ____fput+0x37/0x40 fs/file_table.c:243 task_work_run+0x243/0x2c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x10e1/0x38d0 kernel/exit.c:867 do_group_exit+0x1a0/0x360 kernel/exit.c:970 SYSC_exit_group+0x21/0x30 kernel/exit.c:981 SyS_exit_group+0x25/0x30 kernel/exit.c:979 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 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 kmem_cache_alloc+0xaab/0xb90 mm/slub.c:2756 inet_twsk_alloc+0x13b/0xc00 net/ipv4/inet_timewait_sock.c:163 tcp_time_wait+0xd9/0xf50 net/ipv4/tcp_minisocks.c:258 tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003 tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331 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_close+0x277/0x18f0 net/ipv4/tcp.c:2269 inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435 sock_release net/socket.c:595 [inline] sock_close+0xe0/0x300 net/socket.c:1149 __fput+0x49e/0xa10 fs/file_table.c:209 ____fput+0x37/0x40 fs/file_table.c:243 task_work_run+0x243/0x2c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x10e1/0x38d0 kernel/exit.c:867 do_group_exit+0x1a0/0x360 kernel/exit.c:970 SYSC_exit_group+0x21/0x30 kernel/exit.c:981 SyS_exit_group+0x25/0x30 kernel/exit.c:979 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Fixes: da5e36308d9f ("soreuseport: TCP/IPv4 implementation") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

tcp/dccp: fix old style declarations

2016-01-31T19:23:37Z

[ Upstream commit 8695a144da9e500a5a60fa34c06694346ec1048f ] I’m using the compilation flag -Werror=old-style-declaration, which requires that the “inline” word would come at the beginning of the code line. $ make drivers/net/ethernet/intel/e1000e/e1000e.ko ... include/net/inet_timewait_sock.h:116:1: error: ‘inline’ is not at beginning of declaration [-Werror=old-style-declaration] static void inline inet_twsk_schedule(struct inet_timewait_sock *tw, int timeo) include/net/inet_timewait_sock.h:121:1: error: ‘inline’ is not at beginning of declaration [-Werror=old-style-declaration] static void inline inet_twsk_reschedule(struct inet_timewait_sock *tw, int timeo) Fixes: ed2e92394589 ("tcp/dccp: fix timewait races in timer handling") Signed-off-by: Raanan Avargil Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp/dccp: fix timewait races in timer handling

2016-01-31T19:23:37Z

[ Upstream commit ed2e923945892a8372ab70d2f61d364b0b6d9054 ] When creating a timewait socket, we need to arm the timer before allowing other cpus to find it. The signal allowing cpus to find the socket is setting tw_refcnt to non zero value. As we set tw_refcnt in __inet_twsk_hashdance(), we therefore need to call inet_twsk_schedule() first. This also means we need to remove tw_refcnt changes from inet_twsk_schedule() and let the caller handle it. Note that because we use mod_timer_pinned(), we have the guarantee the timer wont expire before we set tw_refcnt as we run in BH context. To make things more readable I introduced inet_twsk_reschedule() helper. When rearming the timer, we can use mod_timer_pending() to make sure we do not rearm a canceled timer. Note: This bug can possibly trigger if packets of a flow can hit multiple cpus. This does not normally happen, unless flow steering is broken somehow. This explains this bug was spotted ~5 months after its introduction. A similar fix is needed for SYN_RECV sockets in reqsk_queue_hash_req(), but will be provided in a separate patch for proper tracking. Fixes: 789f558cfb36 ("tcp/dccp: get rid of central timewait timer") Signed-off-by: Eric Dumazet Reported-by: Ying Cai Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp/dccp: get rid of central timewait timer

2015-04-13T20:40:05Z

Using a timer wheel for timewait sockets was nice ~15 years ago when memory was expensive and machines had a single processor. This does not scale, code is ugly and source of huge latencies (Typically 30 ms have been seen, cpus spinning on death_lock spinlock.) We can afford to use an extra 64 bytes per timewait sock and spread timewait load to all cpus to have better behavior. Tested: On following test, /proc/sys/net/ipv4/tcp_tw_recycle is set to 1 on the target (lpaa24) Before patch : lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0 419594 lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0 437171 While test is running, we can observe 25 or even 33 ms latencies. lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23 ... 1000 packets transmitted, 1000 received, 0% packet loss, time 20601ms rtt min/avg/max/mdev = 0.020/0.217/25.771/1.535 ms, pipe 2 lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23 ... 1000 packets transmitted, 1000 received, 0% packet loss, time 20702ms rtt min/avg/max/mdev = 0.019/0.183/33.761/1.441 ms, pipe 2 After patch : About 90% increase of throughput : lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0 810442 lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0 800992 And latencies are kept to minimal values during this load, even if network utilization is 90% higher : lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23 ... 1000 packets transmitted, 1000 received, 0% packet loss, time 19991ms rtt min/avg/max/mdev = 0.023/0.064/0.360/0.042 ms Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: add real socket cookies

2015-03-12T01:55:28Z

A long standing problem in netlink socket dumps is the use of kernel socket addresses as cookies. 1) It is a security concern. 2) Sockets can be reused quite quickly, so there is no guarantee a cookie is used once and identify a flow. 3) request sock, establish sock, and timewait socks for a given flow have different cookies. Part of our effort to bring better TCP statistics requires to switch to a different allocator. In this patch, I chose to use a per network namespace 64bit generator, and to use it only in the case a socket needs to be dumped to netlink. (This might be refined later if needed) Note that I tried to carry cookies from request sock, to establish sock, then timewait sockets. Signed-off-by: Eric Dumazet Cc: Eric Salo Signed-off-by: David S. Miller

inet: move ipv6only in sock_common

2014-07-02T06:46:21Z

When an UDP application switches from AF_INET to AF_INET6 sockets, we have a small performance degradation for IPv4 communications because of extra cache line misses to access ipv6only information. This can also be noticed for TCP listeners, as ipv6_only_sock() is also used from __inet_lookup_listener()->compute_score() This is magnified when SO_REUSEPORT is used. Move ipv6only into struct sock_common so that it is available at no extra cost in lookups. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: tcp: fix flowlabel value in ACK messages send from TIME_WAIT

2014-01-18T01:56:33Z

This patch is following the commit b903d324bee262 (ipv6: tcp: fix TCLASS value in ACK messages sent from TIME_WAIT). For the same reason than tclass, we have to store the flow label in the inet_timewait_sock to provide consistency of flow label on the last ACK. Signed-off-by: Florent Fourcot Signed-off-by: David S. Miller

netdev: inet_timewait_sock.h missing semi-colon when KMEMCHECK is enabled

2013-10-17T19:56:53Z

Fix (a few hundred) build errors due to missing semi-colon when KMEMCHECK is enabled: include/net/inet_timewait_sock.h:139:2: error: expected ',', ';' or '}' before 'int' include/net/inet_timewait_sock.h:148:28: error: 'const struct inet_timewait_sock' has no member named 'tw_death_node' Signed-off-by: Randy Dunlap Signed-off-by: David S. Miller

ipv6: make lookups simpler and faster

2013-10-09T04:01:25Z

TCP listener refactoring, part 4 : To speed up inet lookups, we moved IPv4 addresses from inet to struct sock_common Now is time to do the same for IPv6, because it permits us to have fast lookups for all kind of sockets, including upcoming SYN_RECV. Getting IPv6 addresses in TCP lookups currently requires two extra cache lines, plus a dereference (and memory stall). inet6_sk(sk) does the dereference of inet_sk(__sk)->pinet6 This patch is way bigger than its IPv4 counter part, because for IPv4, we could add aliases (inet_daddr, inet_rcv_saddr), while on IPv6, it's not doable easily. inet6_sk(sk)->daddr becomes sk->sk_v6_daddr inet6_sk(sk)->rcv_saddr becomes sk->sk_v6_rcv_saddr And timewait socket also have tw->tw_v6_daddr & tw->tw_v6_rcv_saddr at the same offset. We get rid of INET6_TW_MATCH() as INET6_MATCH() is now the generic macro. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp/dccp: remove twchain

2013-10-09T03:19:24Z

TCP listener refactoring, part 3 : Our goal is to hash SYN_RECV sockets into main ehash for fast lookup, and parallel SYN processing. Current inet_ehash_bucket contains two chains, one for ESTABLISH (and friend states) sockets, another for TIME_WAIT sockets only. As the hash table is sized to get at most one socket per bucket, it makes little sense to have separate twchain, as it makes the lookup slightly more complicated, and doubles hash table memory usage. If we make sure all socket types have the lookup keys at the same offsets, we can use a generic and faster lookup. It turns out TIME_WAIT and ESTABLISHED sockets already have common lookup fields for IPv4. [ INET_TW_MATCH() is no longer needed ] I'll provide a follow-up to factorize IPv6 lookup as well, to remove INET6_TW_MATCH() This way, SYN_RECV pseudo sockets will be supported the same. A new sock_gen_put() helper is added, doing either a sock_put() or inet_twsk_put() [ and will support SYN_RECV later ]. Note this helper should only be called in real slow path, when rcu lookup found a socket that was moved to another identity (freed/reused immediately), but could eventually be used in other contexts, like sock_edemux() Before patch : dmesg | grep "TCP established" TCP established hash table entries: 524288 (order: 11, 8388608 bytes) After patch : TCP established hash table entries: 524288 (order: 10, 4194304 bytes) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller