==================================================================
BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xde/0x100 net/dccp/ccid.c:188
Read of size 8 at addr ffff888096ce7640 by task kworker/1:3/7783

CPU: 1 PID: 7783 Comm: kworker/1:3 Not tainted 5.0.0+ #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: rcu_gp process_srcu
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 ccid_hc_tx_delete+0xde/0x100 net/dccp/ccid.c:188
 dccp_sk_destruct+0x3f/0x90 net/dccp/proto.c:181
 __sk_destruct+0x55/0x6d0 net/core/sock.c:1699
 __rcu_reclaim kernel/rcu/rcu.h:227 [inline]
 rcu_do_batch kernel/rcu/tree.c:2475 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2788 [inline]
 rcu_core+0x928/0x1390 kernel/rcu/tree.c:2769
 __do_softirq+0x266/0x95a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:374 [inline]
 irq_exit+0x180/0x1d0 kernel/softirq.c:414
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:preempt_latency_start kernel/sched/core.c:3219 [inline]
RIP: 0010:preempt_latency_start kernel/sched/core.c:3214 [inline]
RIP: 0010:preempt_count_add+0xe6/0x1b0 kernel/sched/core.c:3242
Code: 85 c0 75 39 65 4c 8b 24 25 00 ee 01 00 49 8d bc 24 b8 11 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 ab 00 00 00 49 89 9c 24 b8 11 00 00 5b 41 5c 5d c3 48 8b 45
RSP: 0018:ffff88805d517b90 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffffffff870c521d RCX: 0000000000000000
RDX: 1ffff1100baa1e57 RSI: ffffffff8330cf5c RDI: ffff88805d50f2b8
RBP: ffff88805d517ba0 R08: ffff88805d50e100 R09: 0000000000000040
R10: 0000000000000040 R11: ffffc90005b55fcf R12: ffff88805d50e100
R13: 0000000000000001 R14: 0000000000002ced R15: 0000000000000001
 delay_tsc+0x3d/0xc0 arch/x86/lib/delay.c:68
 __delay arch/x86/lib/delay.c:161 [inline]
 __const_udelay+0x5f/0x80 arch/x86/lib/delay.c:175
 try_check_zero+0x201/0x330 kernel/rcu/srcutree.c:709
 srcu_advance_state kernel/rcu/srcutree.c:1146 [inline]
 process_srcu+0x329/0xe20 kernel/rcu/srcutree.c:1241
 process_one_work+0x98e/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 8478:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_kmalloc mm/kasan/common.c:497 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505
 slab_post_alloc_hook mm/slab.h:436 [inline]
 slab_alloc mm/slab.c:3392 [inline]
 kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3554
 ccid_new+0x256/0x3f0 net/dccp/ccid.c:151
 dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44
 __dccp_feat_activate+0x17a/0x270 net/dccp/feat.c:344
 dccp_feat_activate_values+0x33a/0x766 net/dccp/feat.c:1538
 dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline]
 dccp_rcv_state_process+0x116f/0x1935 net/dccp/input.c:680
 dccp_v6_do_rcv+0x269/0xbf0 net/dccp/ipv6.c:641
 sk_backlog_rcv include/net/sock.h:937 [inline]
 __release_sock+0x12e/0x3a0 net/core/sock.c:2413
 release_sock+0x59/0x1c0 net/core/sock.c:2929
 inet_wait_for_connect net/ipv4/af_inet.c:588 [inline]
 __inet_stream_connect+0x59f/0xea0 net/ipv4/af_inet.c:680
 inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719
 __sys_connect+0x266/0x330 net/socket.c:1685
 __do_sys_connect net/socket.c:1696 [inline]
 __se_sys_connect net/socket.c:1693 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1693
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8478:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3764
 ccid_hc_tx_delete+0xc1/0x100 net/dccp/ccid.c:190
 dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53
 __dccp_feat_activate+0x17a/0x270 net/dccp/feat.c:344
 dccp_feat_activate_values+0x33a/0x766 net/dccp/feat.c:1538
 dccp_create_openreq_child+0x40c/0x570 net/dccp/minisocks.c:127
 dccp_v6_request_recv_sock+0x214/0x1da0 net/dccp/ipv6.c:469
 dccp_check_req+0x35c/0x6f0 net/dccp/minisocks.c:196
 dccp_v6_rcv+0x6d7/0x191e net/dccp/ipv6.c:747
 ip6_protocol_deliver_rcu+0x303/0x16c0 net/ipv6/ip6_input.c:394
 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434
 NF_HOOK include/linux/netfilter.h:289 [inline]
 NF_HOOK include/linux/netfilter.h:283 [inline]
 ip6_input+0xe4/0x3f0 net/ipv6/ip6_input.c:443
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x1e7/0x320 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:289 [inline]
 NF_HOOK include/linux/netfilter.h:283 [inline]
 ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:272
 __netif_receive_skb_one_core+0x115/0x1a0 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+0x4fa/0x1070 net/core/dev.c:6412
 __do_softirq+0x266/0x95a kernel/softirq.c:293

The buggy address belongs to the object at ffff888096ce7640
 which belongs to the cache ccid2_hc_tx_sock of size 1240
The buggy address is located 0 bytes inside of
 1240-byte region [ffff888096ce7640, ffff888096ce7b18)
The buggy address belongs to the page:
page:ffffea00025b3980 count:1 mapcount:0 mapping:ffff88821670a480 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffff88809b241648 ffffea00014da188 ffff88821670a480
raw: 0000000000000000 ffff888096ce6040 0000000100000005 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888096ce7500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888096ce7580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888096ce7600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                           ^
 ffff888096ce7680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888096ce7700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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