kernel/linux.git/net/dccp/input.c, branch v6.12.80

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

net: dccp: kerneldoc fixes

2020-07-14T00:20:39+00:00

Simple fixes which require no deep knowledge of the code. Cc: Gerrit Renker Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

tcp: Refactor pingpong code

2019-01-27T21:29:43+00:00

Instead of using pingpong as a single bit information, we refactor the code to treat it as a counter. When interactive session is detected, we set pingpong count to TCP_PINGPONG_THRESH. And when pingpong count is >= TCP_PINGPONG_THRESH, we consider the session in pingpong mode. This patch is a pure refactor and sets foundation for the next patch. This patch itself does not change any pingpong logic. Signed-off-by: Wei Wang Signed-off-by: Yuchung Cheng Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp/dccp: fix lockdep issue when SYN is backlogged

2018-10-01T22:42:13+00:00

In normal SYN processing, packets are handled without listener lock and in RCU protected ingress path. But syzkaller is known to be able to trick us and SYN packets might be processed in process context, after being queued into socket backlog. In commit 06f877d613be ("tcp/dccp: fix other lockdep splats accessing ireq_opt") I made a very stupid fix, that happened to work mostly because of the regular path being RCU protected. Really the thing protecting ireq->ireq_opt is RCU read lock, and the pseudo request refcnt is not relevant. This patch extends what I did in commit 449809a66c1d ("tcp/dccp: block BH for SYN processing") by adding an extra rcu_read_{lock|unlock} pair in the paths that might be taken when processing SYN from socket backlog (thus possibly in process context) Fixes: 06f877d613be ("tcp/dccp: fix other lockdep splats accessing ireq_opt") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller

net: dccp: mark expected switch fall-throughs

2017-10-16T20:15:21+00:00

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Notice that for options.c file, I placed the "fall through" comment on its own line, which is what GCC is expecting to find. Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller

dccp: make const array error_code static

2017-07-13T16:24:02+00:00

Don't populate array error_code on the stack but make it static. Makes the object code smaller by almost 250 bytes: Before: text data bss dec hex filename 10366 983 0 11349 2c55 net/dccp/input.o After: text data bss dec hex filename 10161 1039 0 11200 2bc0 net/dccp/input.o Signed-off-by: Colin Ian King Signed-off-by: David S. Miller

tcp/dccp: block BH for SYN processing

2017-03-01T23:03:31+00:00

SYN processing really was meant to be handled from BH. When I got rid of BH blocking while processing socket backlog in commit 5413d1babe8f ("net: do not block BH while processing socket backlog"), I forgot that a malicious user could transition to TCP_LISTEN from a state that allowed (SYN) packets to be parked in the socket backlog while socket is owned by the thread doing the listen() call. Sure enough syzkaller found this and reported the bug ;) ================================= [ INFO: inconsistent lock state ] 4.10.0+ #60 Not tainted --------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. syz-executor0/5090 [HC0[0]:SC0[0]:HE1:SE1] takes: (&(&hashinfo->ehash_locks[i])->rlock){+.?...}, at: [] spin_lock include/linux/spinlock.h:299 [inline] (&(&hashinfo->ehash_locks[i])->rlock){+.?...}, at: [] inet_ehash_insert+0x240/0xad0 net/ipv4/inet_hashtables.c:407 {IN-SOFTIRQ-W} state was registered at: mark_irqflags kernel/locking/lockdep.c:2923 [inline] __lock_acquire+0xbcf/0x3270 kernel/locking/lockdep.c:3295 lock_acquire+0x241/0x580 kernel/locking/lockdep.c:3753 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] inet_ehash_insert+0x240/0xad0 net/ipv4/inet_hashtables.c:407 reqsk_queue_hash_req net/ipv4/inet_connection_sock.c:753 [inline] inet_csk_reqsk_queue_hash_add+0x1b7/0x2a0 net/ipv4/inet_connection_sock.c:764 tcp_conn_request+0x25cc/0x3310 net/ipv4/tcp_input.c:6399 tcp_v4_conn_request+0x157/0x220 net/ipv4/tcp_ipv4.c:1262 tcp_rcv_state_process+0x802/0x4130 net/ipv4/tcp_input.c:5889 tcp_v4_do_rcv+0x56b/0x940 net/ipv4/tcp_ipv4.c:1433 tcp_v4_rcv+0x2e12/0x3210 net/ipv4/tcp_ipv4.c:1711 ip_local_deliver_finish+0x4ce/0xc40 net/ipv4/ip_input.c:216 NF_HOOK include/linux/netfilter.h:257 [inline] ip_local_deliver+0x1ce/0x710 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:492 [inline] ip_rcv_finish+0xb1d/0x2110 net/ipv4/ip_input.c:396 NF_HOOK include/linux/netfilter.h:257 [inline] ip_rcv+0xd90/0x19c0 net/ipv4/ip_input.c:487 __netif_receive_skb_core+0x1ad1/0x3400 net/core/dev.c:4179 __netif_receive_skb+0x2a/0x170 net/core/dev.c:4217 netif_receive_skb_internal+0x1d6/0x430 net/core/dev.c:4245 napi_skb_finish net/core/dev.c:4602 [inline] napi_gro_receive+0x4e6/0x680 net/core/dev.c:4636 e1000_receive_skb drivers/net/ethernet/intel/e1000/e1000_main.c:4033 [inline] e1000_clean_rx_irq+0x5e0/0x1490 drivers/net/ethernet/intel/e1000/e1000_main.c:4489 e1000_clean+0xb9a/0x2910 drivers/net/ethernet/intel/e1000/e1000_main.c:3834 napi_poll net/core/dev.c:5171 [inline] net_rx_action+0xe70/0x1900 net/core/dev.c:5236 __do_softirq+0x2fb/0xb7d kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x19e/0x1d0 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:658 [inline] do_IRQ+0x81/0x1a0 arch/x86/kernel/irq.c:250 ret_from_intr+0x0/0x20 native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53 arch_safe_halt arch/x86/include/asm/paravirt.h:98 [inline] default_idle+0x8f/0x410 arch/x86/kernel/process.c:271 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:262 default_idle_call+0x36/0x60 kernel/sched/idle.c:96 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x348/0x440 kernel/sched/idle.c:243 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:345 start_secondary+0x344/0x440 arch/x86/kernel/smpboot.c:272 verify_cpu+0x0/0xfc irq event stamp: 1741 hardirqs last enabled at (1741): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (1741): [] _raw_spin_unlock_irqrestore+0xf7/0x1a0 kernel/locking/spinlock.c:191 hardirqs last disabled at (1740): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (1740): [] _raw_spin_lock_irqsave+0xa2/0x110 kernel/locking/spinlock.c:159 softirqs last enabled at (1738): [] __do_softirq+0x7cf/0xb7d kernel/softirq.c:310 softirqs last disabled at (1571): [] do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:902 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&hashinfo->ehash_locks[i])->rlock); lock(&(&hashinfo->ehash_locks[i])->rlock); *** DEADLOCK *** 1 lock held by syz-executor0/5090: #0: (sk_lock-AF_INET6){+.+.+.}, at: [] lock_sock include/net/sock.h:1460 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [] sock_setsockopt+0x233/0x1e40 net/core/sock.c:683 stack backtrace: CPU: 1 PID: 5090 Comm: syz-executor0 Not tainted 4.10.0+ #60 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0x292/0x398 lib/dump_stack.c:51 print_usage_bug+0x3ef/0x450 kernel/locking/lockdep.c:2387 valid_state kernel/locking/lockdep.c:2400 [inline] mark_lock_irq kernel/locking/lockdep.c:2602 [inline] mark_lock+0xf30/0x1410 kernel/locking/lockdep.c:3065 mark_irqflags kernel/locking/lockdep.c:2941 [inline] __lock_acquire+0x6dc/0x3270 kernel/locking/lockdep.c:3295 lock_acquire+0x241/0x580 kernel/locking/lockdep.c:3753 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] inet_ehash_insert+0x240/0xad0 net/ipv4/inet_hashtables.c:407 reqsk_queue_hash_req net/ipv4/inet_connection_sock.c:753 [inline] inet_csk_reqsk_queue_hash_add+0x1b7/0x2a0 net/ipv4/inet_connection_sock.c:764 dccp_v6_conn_request+0xada/0x11b0 net/dccp/ipv6.c:380 dccp_rcv_state_process+0x51e/0x1660 net/dccp/input.c:606 dccp_v6_do_rcv+0x213/0x350 net/dccp/ipv6.c:632 sk_backlog_rcv include/net/sock.h:896 [inline] __release_sock+0x127/0x3a0 net/core/sock.c:2052 release_sock+0xa5/0x2b0 net/core/sock.c:2539 sock_setsockopt+0x60f/0x1e40 net/core/sock.c:1016 SYSC_setsockopt net/socket.c:1782 [inline] SyS_setsockopt+0x2fb/0x3a0 net/socket.c:1765 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x4458b9 RSP: 002b:00007fe8b26c2b58 EFLAGS: 00000292 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000004458b9 RDX: 000000000000001a RSI: 0000000000000001 RDI: 0000000000000006 RBP: 00000000006e2110 R08: 0000000000000010 R09: 0000000000000000 R10: 00000000208c3000 R11: 0000000000000292 R12: 0000000000708000 R13: 0000000020000000 R14: 0000000000001000 R15: 0000000000000000 Fixes: 5413d1babe8f ("net: do not block BH while processing socket backlog") Signed-off-by: Eric Dumazet Reported-by: Andrey Konovalov Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller

dccp: fix freeing skb too early for IPV6_RECVPKTINFO

2017-02-17T18:36:25+00:00

In the current DCCP implementation an skb for a DCCP_PKT_REQUEST packet is forcibly freed via __kfree_skb in dccp_rcv_state_process if dccp_v6_conn_request successfully returns. However, if IPV6_RECVPKTINFO is set on a socket, the address of the skb is saved to ireq->pktopts and the ref count for skb is incremented in dccp_v6_conn_request, so skb is still in use. Nevertheless, it gets freed in dccp_rcv_state_process. Fix by calling consume_skb instead of doing goto discard and therefore calling __kfree_skb. Similar fixes for TCP: fb7e2399ec17f1004c0e0ccfd17439f8759ede01 [TCP]: skb is unexpectedly freed. 0aea76d35c9651d55bbaf746e7914e5f9ae5a25d tcp: SYN packets are now simply consumed Signed-off-by: Andrey Konovalov Acked-by: Eric Dumazet Signed-off-by: David S. Miller

dccp: do not assume DCCP code is non preemptible

2016-05-02T21:02:25+00:00

DCCP uses the generic backlog code, and this will soon be changed to not disable BH when protocol is called back. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller