kernel/git/stable/linux.git/net/dccp, branch linux-4.20.y

dccp: fool proof ccid_hc_[rt]x_parse_options()

2019-02-12T19:02:32+00:00

[ Upstream commit 9b1f19d810e92d6cdc68455fbc22d9f961a58ce1 ] Similarly to commit 276bdb82dedb ("dccp: check ccid before dereferencing") it is wise to test for a NULL ccid. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.0.0-rc3+ #37 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ccid_hc_tx_parse_options net/dccp/ccid.h:205 [inline] RIP: 0010:dccp_parse_options+0x8d9/0x12b0 net/dccp/options.c:233 Code: c5 0f b6 75 b3 80 38 00 0f 85 d6 08 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 45 b8 4c 8b b8 f8 07 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 95 08 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b kobject: 'loop5' (0000000080f78fc1): kobject_uevent_env RSP: 0018:ffff8880a94df0b8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880858ac723 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000007 RDI: 0000000000000001 RBP: ffff8880a94df140 R08: 0000000000000001 R09: ffff888061b83a80 R10: ffffed100c370752 R11: ffff888061b83a97 R12: 0000000000000026 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0defa33518 CR3: 000000008db5e000 CR4: 00000000001406e0 kobject: 'loop5' (0000000080f78fc1): fill_kobj_path: path = '/devices/virtual/block/loop5' DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dccp_rcv_state_process+0x2b6/0x1af6 net/dccp/input.c:654 dccp_v4_do_rcv+0x100/0x190 net/dccp/ipv4.c:688 sk_backlog_rcv include/net/sock.h:936 [inline] __sk_receive_skb+0x3a9/0xea0 net/core/sock.c:473 dccp_v4_rcv+0x10cb/0x1f80 net/dccp/ipv4.c:880 ip_protocol_deliver_rcu+0xb6/0xa20 net/ipv4/ip_input.c:208 ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:234 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip_local_deliver+0x1f0/0x740 net/ipv4/ip_input.c:255 dst_input include/net/dst.h:450 [inline] ip_rcv_finish+0x1f4/0x2f0 net/ipv4/ip_input.c:414 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip_rcv+0xed/0x620 net/ipv4/ip_input.c:524 __netif_receive_skb_one_core+0x160/0x210 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083 process_backlog+0x206/0x750 net/core/dev.c:5923 napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x76d/0x1930 net/core/dev.c:6412 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:654 [inline] run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646 smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Modules linked in: ---[ end trace 58a0ba03bea2c376 ]--- RIP: 0010:ccid_hc_tx_parse_options net/dccp/ccid.h:205 [inline] RIP: 0010:dccp_parse_options+0x8d9/0x12b0 net/dccp/options.c:233 Code: c5 0f b6 75 b3 80 38 00 0f 85 d6 08 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 45 b8 4c 8b b8 f8 07 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 95 08 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b RSP: 0018:ffff8880a94df0b8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880858ac723 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000007 RDI: 0000000000000001 RBP: ffff8880a94df140 R08: 0000000000000001 R09: ffff888061b83a80 R10: ffffed100c370752 R11: ffff888061b83a97 R12: 0000000000000026 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0defa33518 CR3: 0000000009871000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Gerrit Renker Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Revert "net: simplify sock_poll_wait"

2018-10-23T17:57:06+00:00

This reverts commit dd979b4df817e9976f18fb6f9d134d6bc4a3c317. This broke tcp_poll for SMC fallback: An AF_SMC socket establishes an internal TCP socket for the initial handshake with the remote peer. Whenever the SMC connection can not be established this TCP socket is used as a fallback. All socket operations on the SMC socket are then forwarded to the TCP socket. In case of poll, the file->private_data pointer references the SMC socket because the TCP socket has no file assigned. This causes tcp_poll to wait on the wrong socket. Signed-off-by: Karsten Graul Signed-off-by: David S. Miller

inet: make sure to grab rcu_read_lock before using ireq->ireq_opt

2018-10-02T22:52:12+00:00

Timer handlers do not imply rcu_read_lock(), so my recent fix triggered a LOCKDEP warning when SYNACK is retransmit. Lets add rcu_read_lock()/rcu_read_unlock() pairs around ireq->ireq_opt usages instead of guessing what is done by callers, since it is not worth the pain. Get rid of ireq_opt_deref() helper since it hides the logic without real benefit, since it is now a standard rcu_dereference(). Fixes: 1ad98e9d1bdf ("tcp/dccp: fix lockdep issue when SYN is backlogged") Signed-off-by: Eric Dumazet Reported-by: Willem de Bruijn 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

Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net

2018-08-09T18:52:36+00:00

Overlapping changes in RXRPC, changing to ktime_get_seconds() whilst adding some tracepoints. Signed-off-by: David S. Miller

dccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart()

2018-08-07T22:34:44+00:00

The shift of 'cwnd' with '(now - hc->tx_lsndtime) / hc->tx_rto' value can lead to undefined behavior [1]. In order to fix this use a gradual shift of the window with a 'while' loop, similar to what tcp_cwnd_restart() is doing. When comparing delta and RTO there is a minor difference between TCP and DCCP, the last one also invokes dccp_cwnd_restart() and reduces 'cwnd' if delta equals RTO. That case is preserved in this change. [1]: [40850.963623] UBSAN: Undefined behaviour in net/dccp/ccids/ccid2.c:237:7 [40851.043858] shift exponent 67 is too large for 32-bit type 'unsigned int' [40851.127163] CPU: 3 PID: 15940 Comm: netstress Tainted: G W E 4.18.0-rc7.x86_64 #1 ... [40851.377176] Call Trace: [40851.408503] dump_stack+0xf1/0x17b [40851.451331] ? show_regs_print_info+0x5/0x5 [40851.503555] ubsan_epilogue+0x9/0x7c [40851.548363] __ubsan_handle_shift_out_of_bounds+0x25b/0x2b4 [40851.617109] ? __ubsan_handle_load_invalid_value+0x18f/0x18f [40851.686796] ? xfrm4_output_finish+0x80/0x80 [40851.739827] ? lock_downgrade+0x6d0/0x6d0 [40851.789744] ? xfrm4_prepare_output+0x160/0x160 [40851.845912] ? ip_queue_xmit+0x810/0x1db0 [40851.895845] ? ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp] [40851.963530] ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp] [40852.029063] dccp_xmit_packet+0x1d3/0x720 [dccp] [40852.086254] dccp_write_xmit+0x116/0x1d0 [dccp] [40852.142412] dccp_sendmsg+0x428/0xb20 [dccp] [40852.195454] ? inet_dccp_listen+0x200/0x200 [dccp] [40852.254833] ? sched_clock+0x5/0x10 [40852.298508] ? sched_clock+0x5/0x10 [40852.342194] ? inet_create+0xdf0/0xdf0 [40852.388988] sock_sendmsg+0xd9/0x160 ... Fixes: 113ced1f52e5 ("dccp ccid-2: Perform congestion-window validation") Signed-off-by: Alexey Kodanev Signed-off-by: David S. Miller

net: simplify sock_poll_wait

2018-07-30T16:10:25+00:00

The wait_address argument is always directly derived from the filp argument, so remove it. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller

Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL

2018-06-28T17:40:47+00:00

The poll() changes were not well thought out, and completely unexplained. They also caused a huge performance regression, because "->poll()" was no longer a trivial file operation that just called down to the underlying file operations, but instead did at least two indirect calls. Indirect calls are sadly slow now with the Spectre mitigation, but the performance problem could at least be largely mitigated by changing the "->get_poll_head()" operation to just have a per-file-descriptor pointer to the poll head instead. That gets rid of one of the new indirections. But that doesn't fix the new complexity that is completely unwarranted for the regular case. The (undocumented) reason for the poll() changes was some alleged AIO poll race fixing, but we don't make the common case slower and more complex for some uncommon special case, so this all really needs way more explanations and most likely a fundamental redesign. [ This revert is a revert of about 30 different commits, not reverted individually because that would just be unnecessarily messy - Linus ] Cc: Al Viro Cc: Christoph Hellwig Signed-off-by: Linus Torvalds

net: dccp: switch rx_tstamp_last_feedback to monotonic clock

2018-06-23T01:46:44+00:00

To compute delays, better not use time of the day which can be changed by admins or malicious programs. Also change ccid3_first_li() to use s64 type for delta variable to avoid potential overflows. Signed-off-by: Eric Dumazet Cc: Gerrit Renker Cc: dccp@vger.kernel.org Signed-off-by: David S. Miller

net: dccp: avoid crash in ccid3_hc_rx_send_feedback()

2018-06-23T01:46:43+00:00

On fast hosts or malicious bots, we trigger a DCCP_BUG() which seems excessive. syzbot reported : BUG: delta (-6195) <= 0 at net/dccp/ccids/ccid3.c:628/ccid3_hc_rx_send_feedback() CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.18.0-rc1+ #112 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 ccid3_hc_rx_send_feedback net/dccp/ccids/ccid3.c:628 [inline] ccid3_hc_rx_packet_recv.cold.16+0x38/0x71 net/dccp/ccids/ccid3.c:793 ccid_hc_rx_packet_recv net/dccp/ccid.h:185 [inline] dccp_deliver_input_to_ccids+0xf0/0x280 net/dccp/input.c:180 dccp_rcv_established+0x87/0xb0 net/dccp/input.c:378 dccp_v4_do_rcv+0x153/0x180 net/dccp/ipv4.c:654 sk_backlog_rcv include/net/sock.h:914 [inline] __sk_receive_skb+0x3ba/0xd80 net/core/sock.c:517 dccp_v4_rcv+0x10f9/0x1f58 net/dccp/ipv4.c:875 ip_local_deliver_finish+0x2eb/0xda0 net/ipv4/ip_input.c:215 NF_HOOK include/linux/netfilter.h:287 [inline] ip_local_deliver+0x1e9/0x750 net/ipv4/ip_input.c:256 dst_input include/net/dst.h:450 [inline] ip_rcv_finish+0x823/0x2220 net/ipv4/ip_input.c:396 NF_HOOK include/linux/netfilter.h:287 [inline] ip_rcv+0xa18/0x1284 net/ipv4/ip_input.c:492 __netif_receive_skb_core+0x2488/0x3680 net/core/dev.c:4628 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4693 process_backlog+0x219/0x760 net/core/dev.c:5373 napi_poll net/core/dev.c:5771 [inline] net_rx_action+0x7da/0x1980 net/core/dev.c:5837 __do_softirq+0x2e8/0xb17 kernel/softirq.c:284 run_ksoftirqd+0x86/0x100 kernel/softirq.c:645 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Gerrit Renker Cc: dccp@vger.kernel.org Signed-off-by: David S. Miller