INFO: task syz-executor.4:28817 blocked for more than 143 seconds. Not tainted 5.6.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28648 28817 9830 0x00000004 Call Trace: context_switch kernel/sched/core.c:3386 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4082 schedule+0xdc/0x2b0 kernel/sched/core.c:4156 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4215 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 hashlimit_mt_check_common.isra.0+0x341/0x1500 net/netfilter/xt_hashlimit.c:889 hashlimit_mt_check_v1+0x325/0x3ab net/netfilter/xt_hashlimit.c:918 xt_check_match+0x280/0x690 net/netfilter/x_tables.c:501 check_match net/ipv6/netfilter/ip6_tables.c:489 [inline] find_check_match net/ipv6/netfilter/ip6_tables.c:506 [inline] find_check_entry.isra.0+0x389/0x9d0 net/ipv6/netfilter/ip6_tables.c:557 translate_table+0xd15/0x1860 net/ipv6/netfilter/ip6_tables.c:734 do_replace net/ipv6/netfilter/ip6_tables.c:1153 [inline] do_ip6t_set_ctl+0x2fe/0x4c8 net/ipv6/netfilter/ip6_tables.c:1681 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x77/0xd0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt net/ipv6/ipv6_sockglue.c:949 [inline] ipv6_setsockopt+0x147/0x180 net/ipv6/ipv6_sockglue.c:933 tcp_setsockopt net/ipv4/tcp.c:3165 [inline] tcp_setsockopt+0x8f/0xe0 net/ipv4/tcp.c:3159 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3149 __sys_setsockopt+0x261/0x4c0 net/socket.c:2130 __do_sys_setsockopt net/socket.c:2146 [inline] __se_sys_setsockopt net/socket.c:2143 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2143 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c449 Code: Bad RIP value. RSP: 002b:00007f65ba07ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f65ba07f6d4 RCX: 000000000045c449 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000007 RBP: 000000000076bfc0 R08: 00000000000003a8 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a09 R14: 00000000004d5720 R15: 000000000076bfcc INFO: task syz-executor.4:28821 blocked for more than 143 seconds. Not tainted 5.6.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28648 28821 9830 0x00004004 Call Trace: context_switch kernel/sched/core.c:3386 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4082 schedule+0xdc/0x2b0 kernel/sched/core.c:4156 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4215 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 hashlimit_mt_check_common.isra.0+0x341/0x1500 net/netfilter/xt_hashlimit.c:889 hashlimit_mt_check_v1+0x325/0x3ab net/netfilter/xt_hashlimit.c:918 xt_check_match+0x280/0x690 net/netfilter/x_tables.c:501 check_match net/ipv6/netfilter/ip6_tables.c:489 [inline] find_check_match net/ipv6/netfilter/ip6_tables.c:506 [inline] find_check_entry.isra.0+0x389/0x9d0 net/ipv6/netfilter/ip6_tables.c:557 translate_table+0xd15/0x1860 net/ipv6/netfilter/ip6_tables.c:734 do_replace net/ipv6/netfilter/ip6_tables.c:1153 [inline] do_ip6t_set_ctl+0x2fe/0x4c8 net/ipv6/netfilter/ip6_tables.c:1681 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x77/0xd0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt net/ipv6/ipv6_sockglue.c:949 [inline] ipv6_setsockopt+0x147/0x180 net/ipv6/ipv6_sockglue.c:933 tcp_setsockopt net/ipv4/tcp.c:3165 [inline] tcp_setsockopt+0x8f/0xe0 net/ipv4/tcp.c:3159 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3149 __sys_setsockopt+0x261/0x4c0 net/socket.c:2130 __do_sys_setsockopt net/socket.c:2146 [inline] __se_sys_setsockopt net/socket.c:2143 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2143 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c449 Code: Bad RIP value. RSP: 002b:00007f65ba01bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f65ba01c6d4 RCX: 000000000045c449 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000007 RBP: 000000000076c1a0 R08: 00000000000003a8 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a09 R14: 00000000004d5720 R15: 000000000076c1ac Showing all locks held in the system: 5 locks held by kworker/u4:6/409: 1 lock held by khungtaskd/865: #0: ffffffff89bac240 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5333 1 lock held by rsyslogd/9684: #0: ffff8880948b0ba0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:821 2 locks held by getty/9774: #0: ffff888097367090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900061b32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9775: #0: ffff8880a448e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900061e32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9776: #0: ffff888097229090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000612f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9777: #0: ffff888097368090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900061c32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9778: #0: ffff8880a1d14090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900061d32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9779: #0: ffff888096ce5090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900061a32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9780: #0: ffff888097155090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900061272e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.1/28758: 1 lock held by syz-executor.4/28817: #0: ffffffff8a7d1820 (hashlimit_mutex){+.+.}, at: hashlimit_mt_check_common.isra.0+0x341/0x1500 net/netfilter/xt_hashlimit.c:889 1 lock held by syz-executor.4/28821: #0: ffffffff8a7d1820 (hashlimit_mutex){+.+.}, at: hashlimit_mt_check_common.isra.0+0x341/0x1500 net/netfilter/xt_hashlimit.c:889 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 865 Comm: khungtaskd Not tainted 5.6.0-rc1-syzkaller #0 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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb11/0x10c0 kernel/hung_task.c:289 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 409 Comm: kworker/u4:6 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: krdsd rds_tcp_accept_worker RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:write_comp_data+0x0/0x70 kernel/kcov.c:207 Code: 83 fa 02 75 20 48 8b 88 88 13 00 00 8b 80 84 13 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 <65> 4c 8b 04 25 c0 1e 02 00 65 8b 05 18 90 8c 7e a9 00 01 1f 00 75 RSP: 0018:ffffc90001ac7480 EFLAGS: 00000246 RAX: ffff8880a86045c0 RBX: dffffc0000000000 RCX: ffffffff86738b5b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffffc90001ac7488 R08: ffff8880a86045c0 R09: ffffc90001ac7568 R10: fffff52000358eb1 R11: ffffc90001ac758f R12: 0000000000000001 R13: ffff888090325b20 R14: 0000000000000000 R15: ffff888090325b20 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000a3874000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nf_ct_zone_tmpl include/net/netfilter/nf_conntrack_zones.h:33 [inline] resolve_normal_ct net/netfilter/nf_conntrack_core.c:1544 [inline] nf_conntrack_in+0x42b/0x1460 net/netfilter/nf_conntrack_core.c:1708 ipv4_conntrack_local+0x127/0x220 net/netfilter/nf_conntrack_proto.c:200 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:512 nf_hook include/linux/netfilter.h:262 [inline] __ip_local_out+0x403/0x870 net/ipv4/ip_output.c:114 ip_local_out+0x2d/0x1b0 net/ipv4/ip_output.c:123 __ip_queue_xmit+0x878/0x1c20 net/ipv4/ip_output.c:530 ip_queue_xmit+0x5a/0x70 include/net/ip.h:237 __tcp_transmit_skb+0x1aca/0x39b0 net/ipv4/tcp_output.c:1234 tcp_transmit_skb net/ipv4/tcp_output.c:1250 [inline] tcp_write_xmit+0xfa2/0x5c70 net/ipv4/tcp_output.c:2513 __tcp_push_pending_frames+0xb4/0x350 net/ipv4/tcp_output.c:2689 tcp_send_fin+0x12a/0xd70 net/ipv4/tcp_output.c:3235 tcp_shutdown net/ipv4/tcp.c:2321 [inline] tcp_shutdown+0x107/0x130 net/ipv4/tcp.c:2306 inet_shutdown+0x1ba/0x3c0 net/ipv4/af_inet.c:879 kernel_sock_shutdown+0x59/0x70 net/socket.c:3830 rds_tcp_accept_one+0x58e/0xc00 net/rds/tcp_listen.c:245 rds_tcp_accept_worker+0x56/0x80 net/rds/tcp.c:525 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352