linux-stable.git/net/dccp, branch v4.14.78 Linux kernel stable tree inet: make sure to grab rcu_read_lock before using ireq->ireq_opt 2018-10-18T07:16:21+00:00 Eric Dumazet edumazet@google.com 2018-10-02T19:35:05+00:00 c5df58138946fe24d3cb0c99bb6ce04130c657b7 [ Upstream commit 2ab2ddd301a22ca3c5f0b743593e4ad2953dfa53 ] 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 <edumazet@google.com> Reported-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 2ab2ddd301a22ca3c5f0b743593e4ad2953dfa53 ]

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 <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp/dccp: fix lockdep issue when SYN is backlogged 2018-10-18T07:16:20+00:00 Eric Dumazet edumazet@google.com 2018-10-01T22:02:26+00:00 17af5475aef350b78875646b2795381f452de756 [ Upstream commit 1ad98e9d1bdf4724c0a8532fabd84bf3c457c2bc ] 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 <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 1ad98e9d1bdf4724c0a8532fabd84bf3c457c2bc ]

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 <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart() 2018-08-22T05:46:08+00:00 Alexey Kodanev alexey.kodanev@oracle.com 2018-08-07T17:03:57+00:00 64d9b03d082a2b0665ee646459ee60aded8734a0 [ Upstream commit 61ef4b07fcdc30535889990cf4229766502561cf ] 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 <alexey.kodanev@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 61ef4b07fcdc30535889990cf4229766502561cf ]

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 <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: dccp: switch rx_tstamp_last_feedback to monotonic clock 2018-07-22T12:28:44+00:00 Eric Dumazet edumazet@google.com 2018-06-22T13:44:15+00:00 fb6b14663d56afabf86a3a2078c37a8d28fc718a [ Upstream commit 0ce4e70ff00662ad7490e545ba0cd8c1fa179fca ] 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 <edumazet@google.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: dccp@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 0ce4e70ff00662ad7490e545ba0cd8c1fa179fca ]

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 <edumazet@google.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: dccp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: dccp: avoid crash in ccid3_hc_rx_send_feedback() 2018-07-22T12:28:44+00:00 Eric Dumazet edumazet@google.com 2018-06-22T13:44:14+00:00 a3225a836e56487b32f21ff1a8099c731256d10a [ Upstream commit 74174fe5634ffbf645a7ca5a261571f700b2f332 ] 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 <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: dccp@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 74174fe5634ffbf645a7ca5a261571f700b2f332 ]

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 <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: dccp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dccp: don't free ccid2_hc_tx_sock struct in dccp_disconnect() 2018-06-11T20:49:18+00:00 Alexey Kodanev alexey.kodanev@oracle.com 2018-05-21T16:28:44+00:00 0d2eb422fe35342cfb031f543add4a8934c82a32 [ Upstream commit 2677d20677314101293e6da0094ede7b5526d2b1 ] Syzbot reported the use-after-free in timer_is_static_object() [1]. This can happen because the structure for the rto timer (ccid2_hc_tx_sock) is removed in dccp_disconnect(), and ccid2_hc_tx_rto_expire() can be called after that. The report [1] is similar to the one in commit 120e9dabaf55 ("dccp: defer ccid_hc_tx_delete() at dismantle time"). And the fix is the same, delay freeing ccid2_hc_tx_sock structure, so that it is freed in dccp_sk_destruct(). [1] ================================================================== BUG: KASAN: use-after-free in timer_is_static_object+0x80/0x90 kernel/time/timer.c:607 Read of size 8 at addr ffff8801bebb5118 by task syz-executor2/25299 CPU: 1 PID: 25299 Comm: syz-executor2 Not tainted 4.17.0-rc5+ #54 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 timer_is_static_object+0x80/0x90 kernel/time/timer.c:607 debug_object_activate+0x2d9/0x670 lib/debugobjects.c:508 debug_timer_activate kernel/time/timer.c:709 [inline] debug_activate kernel/time/timer.c:764 [inline] __mod_timer kernel/time/timer.c:1041 [inline] mod_timer+0x4d3/0x13b0 kernel/time/timer.c:1102 sk_reset_timer+0x22/0x60 net/core/sock.c:2742 ccid2_hc_tx_rto_expire+0x587/0x680 net/dccp/ccids/ccid2.c:147 call_timer_fn+0x230/0x940 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x79e/0xc50 kernel/time/timer.c:1666 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1d1/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:525 [inline] smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 </IRQ> ... Allocated by task 25374: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151 dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44 __dccp_feat_activate+0x184/0x270 net/dccp/feat.c:344 dccp_feat_activate_values+0x3a7/0x819 net/dccp/feat.c:1538 dccp_create_openreq_child+0x472/0x610 net/dccp/minisocks.c:128 dccp_v4_request_recv_sock+0x12c/0xca0 net/dccp/ipv4.c:408 dccp_v6_request_recv_sock+0x125d/0x1f10 net/dccp/ipv6.c:415 dccp_check_req+0x455/0x6a0 net/dccp/minisocks.c:197 dccp_v4_rcv+0x7b8/0x1f3f net/dccp/ipv4.c:841 ip_local_deliver_finish+0x2e3/0xd80 net/ipv4/ip_input.c:215 NF_HOOK include/linux/netfilter.h:288 [inline] ip_local_deliver+0x1e1/0x720 net/ipv4/ip_input.c:256 dst_input include/net/dst.h:450 [inline] ip_rcv_finish+0x81b/0x2200 net/ipv4/ip_input.c:396 NF_HOOK include/linux/netfilter.h:288 [inline] ip_rcv+0xb70/0x143d net/ipv4/ip_input.c:492 __netif_receive_skb_core+0x26f5/0x3630 net/core/dev.c:4592 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4657 process_backlog+0x219/0x760 net/core/dev.c:5337 napi_poll net/core/dev.c:5735 [inline] net_rx_action+0x7b7/0x1930 net/core/dev.c:5801 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285 Freed by task 25374: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190 dccp_disconnect+0x130/0xc66 net/dccp/proto.c:286 dccp_close+0x3bc/0xe60 net/dccp/proto.c:1045 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:427 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:460 sock_release+0x96/0x1b0 net/socket.c:594 sock_close+0x16/0x20 net/socket.c:1149 __fput+0x34d/0x890 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x1e4/0x290 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801bebb4cc0 which belongs to the cache ccid2_hc_tx_sock of size 1240 The buggy address is located 1112 bytes inside of 1240-byte region [ffff8801bebb4cc0, ffff8801bebb5198) The buggy address belongs to the page: page:ffffea0006faed00 count:1 mapcount:0 mapping:ffff8801bebb41c0 index:0xffff8801bebb5240 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801bebb41c0 ffff8801bebb5240 0000000100000003 raw: ffff8801cdba3138 ffffea0007634120 ffff8801cdbaab40 0000000000000000 page dumped because: kasan: bad access detected ... ================================================================== Reported-by: syzbot+5d47e9ec91a6f15dbd6f@syzkaller.appspotmail.com Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 2677d20677314101293e6da0094ede7b5526d2b1 ]

Syzbot reported the use-after-free in timer_is_static_object() [1].

This can happen because the structure for the rto timer (ccid2_hc_tx_sock)
is removed in dccp_disconnect(), and ccid2_hc_tx_rto_expire() can be
called after that.

The report [1] is similar to the one in commit 120e9dabaf55 ("dccp:
defer ccid_hc_tx_delete() at dismantle time"). And the fix is the same,
delay freeing ccid2_hc_tx_sock structure, so that it is freed in
dccp_sk_destruct().

[1]

==================================================================
BUG: KASAN: use-after-free in timer_is_static_object+0x80/0x90
kernel/time/timer.c:607
Read of size 8 at addr ffff8801bebb5118 by task syz-executor2/25299

CPU: 1 PID: 25299 Comm: syz-executor2 Not tainted 4.17.0-rc5+ #54
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1b9/0x294 lib/dump_stack.c:113
  print_address_description+0x6c/0x20b mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  timer_is_static_object+0x80/0x90 kernel/time/timer.c:607
  debug_object_activate+0x2d9/0x670 lib/debugobjects.c:508
  debug_timer_activate kernel/time/timer.c:709 [inline]
  debug_activate kernel/time/timer.c:764 [inline]
  __mod_timer kernel/time/timer.c:1041 [inline]
  mod_timer+0x4d3/0x13b0 kernel/time/timer.c:1102
  sk_reset_timer+0x22/0x60 net/core/sock.c:2742
  ccid2_hc_tx_rto_expire+0x587/0x680 net/dccp/ccids/ccid2.c:147
  call_timer_fn+0x230/0x940 kernel/time/timer.c:1326
  expire_timers kernel/time/timer.c:1363 [inline]
  __run_timers+0x79e/0xc50 kernel/time/timer.c:1666
  run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
  __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
  invoke_softirq kernel/softirq.c:365 [inline]
  irq_exit+0x1d1/0x200 kernel/softirq.c:405
  exiting_irq arch/x86/include/asm/apic.h:525 [inline]
  smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
  </IRQ>
...
Allocated by task 25374:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
  kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
  ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151
  dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44
  __dccp_feat_activate+0x184/0x270 net/dccp/feat.c:344
  dccp_feat_activate_values+0x3a7/0x819 net/dccp/feat.c:1538
  dccp_create_openreq_child+0x472/0x610 net/dccp/minisocks.c:128
  dccp_v4_request_recv_sock+0x12c/0xca0 net/dccp/ipv4.c:408
  dccp_v6_request_recv_sock+0x125d/0x1f10 net/dccp/ipv6.c:415
  dccp_check_req+0x455/0x6a0 net/dccp/minisocks.c:197
  dccp_v4_rcv+0x7b8/0x1f3f net/dccp/ipv4.c:841
  ip_local_deliver_finish+0x2e3/0xd80 net/ipv4/ip_input.c:215
  NF_HOOK include/linux/netfilter.h:288 [inline]
  ip_local_deliver+0x1e1/0x720 net/ipv4/ip_input.c:256
  dst_input include/net/dst.h:450 [inline]
  ip_rcv_finish+0x81b/0x2200 net/ipv4/ip_input.c:396
  NF_HOOK include/linux/netfilter.h:288 [inline]
  ip_rcv+0xb70/0x143d net/ipv4/ip_input.c:492
  __netif_receive_skb_core+0x26f5/0x3630 net/core/dev.c:4592
  __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4657
  process_backlog+0x219/0x760 net/core/dev.c:5337
  napi_poll net/core/dev.c:5735 [inline]
  net_rx_action+0x7b7/0x1930 net/core/dev.c:5801
  __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285

Freed by task 25374:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
  kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
  __cache_free mm/slab.c:3498 [inline]
  kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
  ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190
  dccp_disconnect+0x130/0xc66 net/dccp/proto.c:286
  dccp_close+0x3bc/0xe60 net/dccp/proto.c:1045
  inet_release+0x104/0x1f0 net/ipv4/af_inet.c:427
  inet6_release+0x50/0x70 net/ipv6/af_inet6.c:460
  sock_release+0x96/0x1b0 net/socket.c:594
  sock_close+0x16/0x20 net/socket.c:1149
  __fput+0x34d/0x890 fs/file_table.c:209
  ____fput+0x15/0x20 fs/file_table.c:243
  task_work_run+0x1e4/0x290 kernel/task_work.c:113
  tracehook_notify_resume include/linux/tracehook.h:191 [inline]
  exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166
  prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
  syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
  do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801bebb4cc0
  which belongs to the cache ccid2_hc_tx_sock of size 1240
The buggy address is located 1112 bytes inside of
  1240-byte region [ffff8801bebb4cc0, ffff8801bebb5198)
The buggy address belongs to the page:
page:ffffea0006faed00 count:1 mapcount:0 mapping:ffff8801bebb41c0
index:0xffff8801bebb5240 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801bebb41c0 ffff8801bebb5240 0000000100000003
raw: ffff8801cdba3138 ffffea0007634120 ffff8801cdbaab40 0000000000000000
page dumped because: kasan: bad access detected
...
==================================================================

Reported-by: syzbot+5d47e9ec91a6f15dbd6f@syzkaller.appspotmail.com
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dccp: fix tasklet usage 2018-05-19T08:20:23+00:00 Eric Dumazet edumazet@google.com 2018-05-03T16:39:20+00:00 91c2d70192c717e8bda6c5524ad682d30ded0bf5 [ Upstream commit a8d7aa17bbc970971ccdf71988ea19230ab368b1 ] syzbot reported a crash in tasklet_action_common() caused by dccp. dccp needs to make sure socket wont disappear before tasklet handler has completed. This patch takes a reference on the socket when arming the tasklet, and moves the sock_put() from dccp_write_xmit_timer() to dccp_write_xmitlet() kernel BUG at kernel/softirq.c:514! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.17.0-rc3+ #30 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515 RSP: 0018:ffff8801d9b3faf8 EFLAGS: 00010246 dccp_close: ABORT with 65423 bytes unread RAX: 1ffff1003b367f6b RBX: ffff8801daf1f3f0 RCX: 0000000000000000 RDX: ffff8801cf895498 RSI: 0000000000000004 RDI: 0000000000000000 RBP: ffff8801d9b3fc40 R08: ffffed0039f12a95 R09: ffffed0039f12a94 dccp_close: ABORT with 65423 bytes unread R10: ffffed0039f12a94 R11: ffff8801cf8954a3 R12: 0000000000000000 R13: ffff8801d9b3fc18 R14: dffffc0000000000 R15: ffff8801cf895490 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2bc28000 CR3: 00000001a08a9000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tasklet_action+0x1d/0x20 kernel/softirq.c:533 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285 dccp_close: ABORT with 65423 bytes unread run_ksoftirqd+0x86/0x100 kernel/softirq.c:646 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164 kthread+0x345/0x410 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Code: 48 8b 85 e8 fe ff ff 48 8b 95 f0 fe ff ff e9 94 fb ff ff 48 89 95 f0 fe ff ff e8 81 53 6e 00 48 8b 95 f0 fe ff ff e9 62 fb ff ff <0f> 0b 48 89 cf 48 89 8d e8 fe ff ff e8 64 53 6e 00 48 8b 8d e8 RIP: tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515 RSP: ffff8801d9b3faf8 Fixes: dc841e30eaea ("dccp: Extend CCID packet dequeueing interface") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: dccp@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit a8d7aa17bbc970971ccdf71988ea19230ab368b1 ]

syzbot reported a crash in tasklet_action_common() caused by dccp.

dccp needs to make sure socket wont disappear before tasklet handler
has completed.

This patch takes a reference on the socket when arming the tasklet,
and moves the sock_put() from dccp_write_xmit_timer() to dccp_write_xmitlet()

kernel BUG at kernel/softirq.c:514!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.17.0-rc3+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515
RSP: 0018:ffff8801d9b3faf8 EFLAGS: 00010246
dccp_close: ABORT with 65423 bytes unread
RAX: 1ffff1003b367f6b RBX: ffff8801daf1f3f0 RCX: 0000000000000000
RDX: ffff8801cf895498 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffff8801d9b3fc40 R08: ffffed0039f12a95 R09: ffffed0039f12a94
dccp_close: ABORT with 65423 bytes unread
R10: ffffed0039f12a94 R11: ffff8801cf8954a3 R12: 0000000000000000
R13: ffff8801d9b3fc18 R14: dffffc0000000000 R15: ffff8801cf895490
FS:  0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bc28000 CR3: 00000001a08a9000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tasklet_action+0x1d/0x20 kernel/softirq.c:533
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
dccp_close: ABORT with 65423 bytes unread
 run_ksoftirqd+0x86/0x100 kernel/softirq.c:646
 smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Code: 48 8b 85 e8 fe ff ff 48 8b 95 f0 fe ff ff e9 94 fb ff ff 48 89 95 f0 fe ff ff e8 81 53 6e 00 48 8b 95 f0 fe ff ff e9 62 fb ff ff <0f> 0b 48 89 cf 48 89 8d e8 fe ff ff e8 64 53 6e 00 48 8b 8d e8
RIP: tasklet_action_common.isra.19+0x6db/0x700 kernel/softirq.c:515 RSP: ffff8801d9b3faf8

Fixes: dc841e30eaea ("dccp: Extend CCID packet dequeueing interface")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: dccp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dccp: initialize ireq->ir_mark 2018-05-16T08:10:24+00:00 Eric Dumazet edumazet@google.com 2018-04-07T20:42:41+00:00 09e45996b3e716693333b998f9fe77df8bc6de50 commit b855ff827476adbdc2259e9895681d82b7b26065 upstream. syzbot reported an uninit-value read of skb->mark in iptable_mangle_hook() Thanks to the nice report, I tracked the problem to dccp not caring of ireq->ir_mark for passive sessions. BUG: KMSAN: uninit-value in ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:66 [inline] BUG: KMSAN: uninit-value in iptable_mangle_hook+0x5e5/0x720 net/ipv4/netfilter/iptable_mangle.c:84 CPU: 0 PID: 5300 Comm: syz-executor3 Not tainted 4.16.0+ #81 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 ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:66 [inline] iptable_mangle_hook+0x5e5/0x720 net/ipv4/netfilter/iptable_mangle.c:84 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline] nf_hook_slow+0x158/0x3d0 net/netfilter/core.c:483 nf_hook include/linux/netfilter.h:243 [inline] __ip_local_out net/ipv4/ip_output.c:113 [inline] ip_local_out net/ipv4/ip_output.c:122 [inline] ip_queue_xmit+0x1d21/0x21c0 net/ipv4/ip_output.c:504 dccp_transmit_skb+0x15eb/0x1900 net/dccp/output.c:142 dccp_xmit_packet+0x814/0x9e0 net/dccp/output.c:281 dccp_write_xmit+0x20f/0x480 net/dccp/output.c:363 dccp_sendmsg+0x12ca/0x12d0 net/dccp/proto.c:818 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] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046 __sys_sendmsg net/socket.c:2080 [inline] SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091 SyS_sendmsg+0x54/0x80 net/socket.c:2087 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x455259 RSP: 002b:00007f1a4473dc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f1a4473e6d4 RCX: 0000000000455259 RDX: 0000000000000000 RSI: 0000000020b76fc8 RDI: 0000000000000015 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004f0 R14: 00000000006fa720 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 ip_queue_xmit+0x1e35/0x21c0 net/ipv4/ip_output.c:502 dccp_transmit_skb+0x15eb/0x1900 net/dccp/output.c:142 dccp_xmit_packet+0x814/0x9e0 net/dccp/output.c:281 dccp_write_xmit+0x20f/0x480 net/dccp/output.c:363 dccp_sendmsg+0x12ca/0x12d0 net/dccp/proto.c:818 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] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046 __sys_sendmsg net/socket.c:2080 [inline] SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091 SyS_sendmsg+0x54/0x80 net/socket.c:2087 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_csk_clone_lock+0x503/0x580 net/ipv4/inet_connection_sock.c:797 dccp_create_openreq_child+0x7f/0x890 net/dccp/minisocks.c:92 dccp_v4_request_recv_sock+0x22c/0xe90 net/dccp/ipv4.c:408 dccp_v6_request_recv_sock+0x290/0x2000 net/dccp/ipv6.c:414 dccp_check_req+0x7b9/0x8f0 net/dccp/minisocks.c:197 dccp_v4_rcv+0x12e4/0x2630 net/dccp/ipv4.c:840 ip_local_deliver_finish+0x6ed/0xd40 net/ipv4/ip_input.c:216 NF_HOOK include/linux/netfilter.h:288 [inline] ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:449 [inline] ip_rcv_finish+0x1253/0x16d0 net/ipv4/ip_input.c:397 NF_HOOK include/linux/netfilter.h:288 [inline] ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562 __netif_receive_skb net/core/dev.c:4627 [inline] process_backlog+0x62d/0xe20 net/core/dev.c:5307 napi_poll net/core/dev.c:5705 [inline] net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771 __do_softirq+0x56d/0x93d kernel/softirq.c:285 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 reqsk_alloc include/net/request_sock.h:88 [inline] inet_reqsk_alloc+0xc4/0x7f0 net/ipv4/tcp_input.c:6145 dccp_v4_conn_request+0x5cc/0x1770 net/dccp/ipv4.c:600 dccp_v6_conn_request+0x299/0x1880 net/dccp/ipv6.c:317 dccp_rcv_state_process+0x2ea/0x2410 net/dccp/input.c:612 dccp_v4_do_rcv+0x229/0x340 net/dccp/ipv4.c:682 dccp_v6_do_rcv+0x16d/0x1220 net/dccp/ipv6.c:578 sk_backlog_rcv include/net/sock.h:908 [inline] __sk_receive_skb+0x60e/0xf20 net/core/sock.c:513 dccp_v4_rcv+0x24d4/0x2630 net/dccp/ipv4.c:874 ip_local_deliver_finish+0x6ed/0xd40 net/ipv4/ip_input.c:216 NF_HOOK include/linux/netfilter.h:288 [inline] ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:449 [inline] ip_rcv_finish+0x1253/0x16d0 net/ipv4/ip_input.c:397 NF_HOOK include/linux/netfilter.h:288 [inline] ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562 __netif_receive_skb net/core/dev.c:4627 [inline] process_backlog+0x62d/0xe20 net/core/dev.c:5307 napi_poll net/core/dev.c:5705 [inline] net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771 __do_softirq+0x56d/0x93d kernel/softirq.c:285 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b855ff827476adbdc2259e9895681d82b7b26065 upstream.

syzbot reported an uninit-value read of skb->mark in iptable_mangle_hook()

Thanks to the nice report, I tracked the problem to dccp not caring
of ireq->ir_mark for passive sessions.

BUG: KMSAN: uninit-value in ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:66 [inline]
BUG: KMSAN: uninit-value in iptable_mangle_hook+0x5e5/0x720 net/ipv4/netfilter/iptable_mangle.c:84
CPU: 0 PID: 5300 Comm: syz-executor3 Not tainted 4.16.0+ #81
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
 ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:66 [inline]
 iptable_mangle_hook+0x5e5/0x720 net/ipv4/netfilter/iptable_mangle.c:84
 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline]
 nf_hook_slow+0x158/0x3d0 net/netfilter/core.c:483
 nf_hook include/linux/netfilter.h:243 [inline]
 __ip_local_out net/ipv4/ip_output.c:113 [inline]
 ip_local_out net/ipv4/ip_output.c:122 [inline]
 ip_queue_xmit+0x1d21/0x21c0 net/ipv4/ip_output.c:504
 dccp_transmit_skb+0x15eb/0x1900 net/dccp/output.c:142
 dccp_xmit_packet+0x814/0x9e0 net/dccp/output.c:281
 dccp_write_xmit+0x20f/0x480 net/dccp/output.c:363
 dccp_sendmsg+0x12ca/0x12d0 net/dccp/proto.c:818
 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]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
 __sys_sendmsg net/socket.c:2080 [inline]
 SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
 SyS_sendmsg+0x54/0x80 net/socket.c:2087
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455259
RSP: 002b:00007f1a4473dc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1a4473e6d4 RCX: 0000000000455259
RDX: 0000000000000000 RSI: 0000000020b76fc8 RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004f0 R14: 00000000006fa720 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
 ip_queue_xmit+0x1e35/0x21c0 net/ipv4/ip_output.c:502
 dccp_transmit_skb+0x15eb/0x1900 net/dccp/output.c:142
 dccp_xmit_packet+0x814/0x9e0 net/dccp/output.c:281
 dccp_write_xmit+0x20f/0x480 net/dccp/output.c:363
 dccp_sendmsg+0x12ca/0x12d0 net/dccp/proto.c:818
 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]
 ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046
 __sys_sendmsg net/socket.c:2080 [inline]
 SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091
 SyS_sendmsg+0x54/0x80 net/socket.c:2087
 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_csk_clone_lock+0x503/0x580 net/ipv4/inet_connection_sock.c:797
 dccp_create_openreq_child+0x7f/0x890 net/dccp/minisocks.c:92
 dccp_v4_request_recv_sock+0x22c/0xe90 net/dccp/ipv4.c:408
 dccp_v6_request_recv_sock+0x290/0x2000 net/dccp/ipv6.c:414
 dccp_check_req+0x7b9/0x8f0 net/dccp/minisocks.c:197
 dccp_v4_rcv+0x12e4/0x2630 net/dccp/ipv4.c:840
 ip_local_deliver_finish+0x6ed/0xd40 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:449 [inline]
 ip_rcv_finish+0x1253/0x16d0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
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
 reqsk_alloc include/net/request_sock.h:88 [inline]
 inet_reqsk_alloc+0xc4/0x7f0 net/ipv4/tcp_input.c:6145
 dccp_v4_conn_request+0x5cc/0x1770 net/dccp/ipv4.c:600
 dccp_v6_conn_request+0x299/0x1880 net/dccp/ipv6.c:317
 dccp_rcv_state_process+0x2ea/0x2410 net/dccp/input.c:612
 dccp_v4_do_rcv+0x229/0x340 net/dccp/ipv4.c:682
 dccp_v6_do_rcv+0x16d/0x1220 net/dccp/ipv6.c:578
 sk_backlog_rcv include/net/sock.h:908 [inline]
 __sk_receive_skb+0x60e/0xf20 net/core/sock.c:513
 dccp_v4_rcv+0x24d4/0x2630 net/dccp/ipv4.c:874
 ip_local_deliver_finish+0x6ed/0xd40 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:449 [inline]
 ip_rcv_finish+0x1253/0x16d0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x47cf/0x4a80 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dccp: check sk for closed state in dccp_sendmsg() 2018-03-31T16:10:40+00:00 Alexey Kodanev alexey.kodanev@oracle.com 2018-03-06T19:57:01+00:00 91d27e0c302501e148460db9981b5b04481781ce [ Upstream commit 67f93df79aeefc3add4e4b31a752600f834236e2 ] dccp_disconnect() sets 'dp->dccps_hc_tx_ccid' tx handler to NULL, therefore if DCCP socket is disconnected and dccp_sendmsg() is called after it, it will cause a NULL pointer dereference in dccp_write_xmit(). This crash and the reproducer was reported by syzbot. Looks like it is reproduced if commit 69c64866ce07 ("dccp: CVE-2017-8824: use-after-free in DCCP code") is applied. Reported-by: syzbot+f99ab3887ab65d70f816@syzkaller.appspotmail.com Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 67f93df79aeefc3add4e4b31a752600f834236e2 ]

dccp_disconnect() sets 'dp->dccps_hc_tx_ccid' tx handler to NULL,
therefore if DCCP socket is disconnected and dccp_sendmsg() is
called after it, it will cause a NULL pointer dereference in
dccp_write_xmit().

This crash and the reproducer was reported by syzbot. Looks like
it is reproduced if commit 69c64866ce07 ("dccp: CVE-2017-8824:
use-after-free in DCCP code") is applied.

Reported-by: syzbot+f99ab3887ab65d70f816@syzkaller.appspotmail.com
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dccp: CVE-2017-8824: use-after-free in DCCP code 2018-02-16T19:22:45+00:00 Mohamed Ghannam simo.ghannam@gmail.com 2017-12-05T20:58:35+00:00 e5e1e153ecd40c2b09c23d2b2c161a6c8ddbba07 commit 69c64866ce072dea1d1e59a0d61e0f66c0dffb76 upstream. Whenever the sock object is in DCCP_CLOSED state, dccp_disconnect() must free dccps_hc_tx_ccid and dccps_hc_rx_ccid and set to NULL. Signed-off-by: Mohamed Ghannam <simo.ghannam@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 69c64866ce072dea1d1e59a0d61e0f66c0dffb76 upstream.

Whenever the sock object is in DCCP_CLOSED state,
dccp_disconnect() must free dccps_hc_tx_ccid and
dccps_hc_rx_ccid and set to NULL.

Signed-off-by: Mohamed Ghannam <simo.ghannam@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>