INFO: task syz.7.66141:14037 blocked for more than 430 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.66141 state:D stack:0 pid:14037 tgid:14037 ppid:5406 task_flags:0x400140 flags:0x00000005 Call trace: [<81b6017c>] (__schedule) from [<81b61614>] (__schedule_loop kernel/sched/core.c:7311 [inline]) [<81b6017c>] (__schedule) from [<81b61614>] (schedule+0x2c/0xec kernel/sched/core.c:7326) r10:85c40200 r9:850b9880 r8:869a0c00 r7:851ec988 r6:df95dea0 r5:df95de30 r4:850b9880 [<81b615e8>] (schedule) from [<807a06ac>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b615e8>] (schedule) from [<807a06ac>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b615e8>] (schedule) from [<807a06ac>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:df95de30 r4:851ec930 [<807a031c>] (fuse_chan_send) from [<807b2c04>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:87c44180 r7:86062b80 r6:8bb20100 r5:87aa66c0 r4:df95dea0 [<807b2ba8>] (__fuse_simple_request) from [<807a83a0>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807b2ba8>] (__fuse_simple_request) from [<807a83a0>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:504) r5:835ce240 r4:85c40200 [<807a8228>] (fuse_flush) from [<80599e2c>] (filp_flush+0x38/0x88 fs/open.c:1471) r8:8bb20140 r7:840a99c0 r6:0000001e r5:8bb20100 r4:85c40200 [<80599df4>] (filp_flush) from [<80599e90>] (filp_close+0x14/0x28 fs/open.c:1484) r7:840a99c0 r6:0000001e r5:85c40200 r4:8bb20100 [<80599e7c>] (filp_close) from [<805cc4b8>] (__range_close fs/file.c:793 [inline]) [<80599e7c>] (filp_close) from [<805cc4b8>] (__do_sys_close_range fs/file.c:854 [inline]) [<80599e7c>] (filp_close) from [<805cc4b8>] (sys_close_range+0x18c/0x224 fs/file.c:818) r5:00000004 r4:8bb20100 [<805cc32c>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf95dfa8 to 0xdf95dff0) dfa0: 00000000 00000000 00000003 0000001e 00000000 7ef38920 dfc0: 00000000 00000000 00000000 000001b4 008fdd13 ffffffff 00000000 003562e4 dfe0: 7ef38848 7ef38838 00028610 001309d0 r10:000001b4 r9:850b9880 r8:8020029c r7:000001b4 r6:00000000 r5:00000000 r4:00000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 29 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express Call trace: [<80201998>] (dump_backtrace) from [<80201a8c>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:60000193 r6:60000193 r5:82333190 r4:00000000 [<80201a74>] (show_stack) from [<8021e60c>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201a74>] (show_stack) from [<8021e60c>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e5b0>] (dump_stack_lvl) from [<8021e638>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000113 r5:00000001 r4:00000001 [<8021e620>] (dump_stack) from [<81b4981c>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b496cc>] (nmi_cpu_backtrace) from [<81b49970>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83320c40 r5:82a1c7b8 r4:ffffffff [<81b4983c>] (nmi_trigger_cpumask_backtrace) from [<8022f0f4>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:851) r9:82a0b2f0 r8:00000001 r7:82a1ce80 r6:82ccae2c r5:00007ee2 r4:00000048 [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b514ac>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b514ac>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b514ac>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b51444>] (sys_info) from [<8038f988>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b51444>] (sys_info) from [<8038f988>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007ee2 r4:0000000a [<8038f5e8>] (watchdog) from [<80281710>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:831d4600 r7:00000000 r6:8038f5e8 r5:83320c40 r4:833dd400 [<802815f4>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xdf8d5fb0 to 0xdf8d5ff8) 5fa0: 00000000 00000000 00000000 00000000 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802815f4 r4:833dd400 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3101 Comm: sshd-session Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] PC is at _raw_spin_unlock_irqrestore+0x28/0x54 kernel/locking/spinlock.c:198 LR is at __mod_timer+0x140/0x408 kernel/time/timer.c:1139 pc : [<81b6aadc>] lr : [<8032f1d8>] psr: 20030013 sp : df801b10 ip : df801b20 fp : df801b1c r10: ffffffff r9 : 82a03d80 r8 : 000e9d08 r7 : 00000000 r6 : dddc6fc0 r5 : dddc6fc0 r4 : 8584b990 r3 : 00002130 r2 : 00000009 r1 : 40030013 r0 : dddc6fc0 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 84a97980 DAC: fffffffd Call trace: frame pointer underflow [<81b6aab4>] (_raw_spin_unlock_irqrestore) from [<8032f1d8>] (__mod_timer+0x140/0x408 kernel/time/timer.c:1139) [<8032f098>] (__mod_timer) from [<8032f4cc>] (mod_timer+0x14/0x18 kernel/time/timer.c:1195) r10:8584b640 r9:000008fb r8:ab47ae6e r7:83e455c0 r6:82e383c0 r5:00000004 r4:8584b640 [<8032f4b8>] (mod_timer) from [<8162acbc>] (sk_reset_timer+0x20/0x70 net/core/sock.c:3724) [<8162ac9c>] (sk_reset_timer) from [<8185b804>] (tcp_send_delayed_ack+0xb4/0x114 net/ipv4/tcp_output.c:4462) r5:00000004 r4:8584b640 [<8185b750>] (tcp_send_delayed_ack) from [<8184500c>] (__tcp_ack_snd_check+0x1f0/0x21c net/ipv4/tcp_input.c:6149) r7:83e455c0 r6:82e383c0 r5:00000001 r4:8584b640 [<81844e1c>] (__tcp_ack_snd_check) from [<8184fae4>] (tcp_ack_snd_check net/ipv4/tcp_input.c:6198 [inline]) [<81844e1c>] (__tcp_ack_snd_check) from [<8184fae4>] (tcp_ack_snd_check net/ipv4/tcp_input.c:6192 [inline]) [<81844e1c>] (__tcp_ack_snd_check) from [<8184fae4>] (tcp_rcv_established+0x46c/0xc98 net/ipv4/tcp_input.c:6692) r6:863b12e0 r5:85a44b40 r4:8584b640 [<8184f678>] (tcp_rcv_established) from [<81862780>] (tcp_v4_do_rcv+0x1c8/0x3c4 net/ipv4/tcp_ipv4.c:1854) r10:8584b640 r9:00000001 r8:82e383c0 r7:00000020 r6:86ba9180 r5:8584b640 r4:85a44b40 [<818625b8>] (tcp_v4_do_rcv) from [<8186458c>] (tcp_v4_rcv+0xb90/0x1314 net/ipv4/tcp_ipv4.c:2248) r7:00000020 r6:8584b734 r5:00000001 r4:85a44b40 [<818639fc>] (tcp_v4_rcv) from [<81826f48>] (ip_protocol_deliver_rcu+0x38/0x268 net/ipv4/ip_input.c:207) r10:dddd25a0 r9:00000000 r8:00000000 r7:82e383c0 r6:82a19104 r5:85a44b40 r4:82a04f6c [<81826f10>] (ip_protocol_deliver_rcu) from [<81827218>] (ip_local_deliver_finish+0xa0/0x204 net/ipv4/ip_input.c:241) r9:dddd2488 r8:00000040 r7:00000000 r6:00000014 r5:82e383c0 r4:85a44b40 [<81827178>] (ip_local_deliver_finish) from [<818273f8>] (NF_HOOK include/linux/netfilter.h:318 [inline]) [<81827178>] (ip_local_deliver_finish) from [<818273f8>] (NF_HOOK include/linux/netfilter.h:312 [inline]) [<81827178>] (ip_local_deliver_finish) from [<818273f8>] (ip_local_deliver+0x7c/0x10c net/ipv4/ip_input.c:262) r7:00000000 r6:82e383c0 r5:8396d000 r4:85a44b40 [<8182737c>] (ip_local_deliver) from [<81826ba8>] (dst_input include/net/dst.h:480 [inline]) [<8182737c>] (ip_local_deliver) from [<81826ba8>] (ip_rcv_finish+0x98/0xb0 net/ipv4/ip_input.c:492) r6:8396d000 r5:82e383c0 r4:85a44b40 [<81826b10>] (ip_rcv_finish) from [<8182756c>] (NF_HOOK include/linux/netfilter.h:318 [inline]) [<81826b10>] (ip_rcv_finish) from [<8182756c>] (NF_HOOK include/linux/netfilter.h:312 [inline]) [<81826b10>] (ip_rcv_finish) from [<8182756c>] (ip_rcv+0xe4/0xec net/ipv4/ip_input.c:612) r7:00000000 r6:82e383c0 r5:8396d000 r4:85a44b40 [<81827488>] (ip_rcv) from [<816603fc>] (__netif_receive_skb_one_core+0x60/0x84 net/core/dev.c:6212) r6:00000000 r5:81827488 r4:8396d000 [<8166039c>] (__netif_receive_skb_one_core) from [<81660468>] (__netif_receive_skb+0x18/0x5c net/core/dev.c:6325) r5:00000001 r4:85a44b40 [<81660450>] (__netif_receive_skb) from [<816607b4>] (process_backlog+0xa0/0x17c net/core/dev.c:6676) r5:00000001 r4:85a44b40 [<81660714>] (process_backlog) from [<81660f94>] (__napi_poll+0x34/0x268 net/core/dev.c:7735) r10:df801ec8 r9:00000000 r8:0000012c r7:00000040 r6:df801ec3 r5:dddd25a0 r4:00000001 [<81660f60>] (__napi_poll) from [<81661524>] (napi_poll net/core/dev.c:7798 [inline]) [<81660f60>] (__napi_poll) from [<81661524>] (net_rx_action+0x35c/0x3e8 net/core/dev.c:7955) r9:00000000 r8:0000012c r7:dddd25a0 r6:dddd25a4 r5:dddd2480 r4:ffffffff [<816611c8>] (net_rx_action) from [<8025a0dc>] (handle_softirqs+0x160/0x4e4 kernel/softirq.c:622) r10:83e455c0 r9:00000008 r8:00000101 r7:0000000c r6:00000004 r5:00000003 r4:82a0308c [<80259f7c>] (handle_softirqs) from [<802012f0>] (__do_softirq+0x14/0x18 kernel/softirq.c:656) r10:00000000 r9:828d54cc r8:00000000 r7:8396d000 r6:00000000 r5:00000001 r4:60030013 [<802012dc>] (__do_softirq) from [<8022729c>] (____do_softirq+0x10/0x14 arch/arm/kernel/irq.c:77) [<8022728c>] (____do_softirq) from [<81b294f0>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40) [<81b294d4>] (call_with_stack) from [<802272d8>] (do_softirq_own_stack+0x38/0x3c arch/arm/kernel/irq.c:82) [<802272a0>] (do_softirq_own_stack) from [<8025a750>] (do_softirq kernel/softirq.c:523 [inline]) [<802272a0>] (do_softirq_own_stack) from [<8025a750>] (do_softirq+0x5c/0x64 kernel/softirq.c:510) [<8025a6f4>] (do_softirq) from [<8025a824>] (__local_bh_enable_ip+0xcc/0xd0 kernel/softirq.c:450) r5:00000001 r4:83e455c0 [<8025a758>] (__local_bh_enable_ip) from [<8165d810>] (local_bh_enable include/linux/bottom_half.h:33 [inline]) [<8025a758>] (__local_bh_enable_ip) from [<8165d810>] (rcu_read_unlock_bh include/linux/rcupdate.h:914 [inline]) [<8025a758>] (__local_bh_enable_ip) from [<8165d810>] (__dev_queue_xmit+0x77c/0x126c net/core/dev.c:4913) r5:8335aa00 r4:00000000 [<8165d094>] (__dev_queue_xmit) from [<8182b05c>] (dev_queue_xmit include/linux/netdevice.h:3448 [inline]) [<8165d094>] (__dev_queue_xmit) from [<8182b05c>] (neigh_hh_output include/net/neighbour.h:544 [inline]) [<8165d094>] (__dev_queue_xmit) from [<8182b05c>] (neigh_output include/net/neighbour.h:558 [inline]) [<8165d094>] (__dev_queue_xmit) from [<8182b05c>] (ip_finish_output2+0x36c/0x790 net/ipv4/ip_output.c:236) r10:82e383c0 r9:00000000 r8:00000010 r7:00000000 r6:0000000e r5:85a44b40 r4:84ecd100 [<8182acf0>] (ip_finish_output2) from [<8182c388>] (__ip_finish_output.part.0+0x9c/0x150 net/ipv4/ip_output.c:314) r8:8396d000 r7:82e383c0 r6:0000ffff r5:8584ae80 r4:85a44b40 [<8182c2ec>] (__ip_finish_output.part.0) from [<8182c478>] (__ip_finish_output+0x3c/0x40 net/ipv4/ip_output.c:304) r9:00000000 r8:8396d000 r7:00000001 r6:8584ae80 r5:82e383c0 r4:85a44b40 [<8182c43c>] (__ip_finish_output) from [<8182c4e4>] (ip_finish_output net/ipv4/ip_output.c:324 [inline]) [<8182c43c>] (__ip_finish_output) from [<8182c4e4>] (NF_HOOK_COND include/linux/netfilter.h:307 [inline]) [<8182c43c>] (__ip_finish_output) from [<8182c4e4>] (ip_output+0x68/0x104 net/ipv4/ip_output.c:437) [<8182c47c>] (ip_output) from [<8182dcd8>] (dst_output include/net/dst.h:470 [inline]) [<8182c47c>] (ip_output) from [<8182dcd8>] (ip_local_out net/ipv4/ip_output.c:131 [inline]) [<8182c47c>] (ip_output) from [<8182dcd8>] (__ip_queue_xmit+0x190/0x528 net/ipv4/ip_output.c:533) r8:8584b138 r7:86ba9180 r6:00000001 r5:8584ae80 r4:85a44b40 [<8182db48>] (__ip_queue_xmit) from [<8182e084>] (ip_queue_xmit+0x14/0x18 net/ipv4/ip_output.c:547) r10:0100007f r9:9563d02c r8:000008fb r7:00000020 r6:0100007f r5:8584ae80 r4:85a44b40 [<8182e070>] (ip_queue_xmit) from [<81855c84>] (__tcp_transmit_skb+0x658/0x10a4 net/ipv4/tcp_output.c:1716) [<8185562c>] (__tcp_transmit_skb) from [<81857c2c>] (tcp_transmit_skb net/ipv4/tcp_output.c:1734 [inline]) [<8185562c>] (__tcp_transmit_skb) from [<81857c2c>] (tcp_write_xmit+0x4dc/0x19e4 net/ipv4/tcp_output.c:3062) r10:736fd04b r9:8584afac r8:00000000 r7:0000ffcb r6:0000ffcb r5:8584ae80 r4:85a44a80 [<81857750>] (tcp_write_xmit) from [<8185916c>] (__tcp_push_pending_frames+0x38/0x11c net/ipv4/tcp_output.c:3245) r10:00000125 r9:83e455c0 r8:838b6400 r7:00000000 r6:8584afac r5:85a44a80 r4:8584ae80 [<81859134>] (__tcp_push_pending_frames) from [<8185a64c>] (tcp_send_fin+0x60/0x2c8 net/ipv4/tcp_output.c:3844) r7:00000000 r6:8584afac r5:85a44a80 r4:8584ae80 [<8185a5ec>] (tcp_send_fin) from [<8184065c>] (tcp_shutdown+0x58/0x5c net/ipv4/tcp.c:3084) r7:00000000 r6:00000002 r5:00000084 r4:8584ae80 [<81840604>] (tcp_shutdown) from [<81885148>] (inet_shutdown+0xf4/0x100 net/ipv4/af_inet.c:931) r5:8344b6c0 r4:8584ae80 [<81885054>] (inet_shutdown) from [<81628108>] (__sys_shutdown_sock net/socket.c:2525 [inline]) [<81885054>] (inet_shutdown) from [<81628108>] (__sys_shutdown_sock net/socket.c:2519 [inline]) [<81885054>] (inet_shutdown) from [<81628108>] (__sys_shutdown+0x78/0xa8 net/socket.c:2541) r7:00000001 r6:838b6400 r5:8344b6c0 r4:00000000 [<81628090>] (__sys_shutdown) from [<81628148>] (__do_sys_shutdown net/socket.c:2546 [inline]) [<81628090>] (__sys_shutdown) from [<81628148>] (sys_shutdown+0x10/0x14 net/socket.c:2544) r9:83e455c0 r8:8020029c r7:00000125 r6:01df11d8 r5:0051a13c r4:01dfc578 [<81628138>] (sys_shutdown) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf94dfa8 to 0xdf94dff0) dfa0: 01dfc578 0051a13c 00000009 00000001 00000000 00000000 dfc0: 01dfc578 0051a13c 01df11d8 00000125 00000006 005120a8 00000000 00000003 dfe0: 00538ccc 7ea050dc 004b7820 769c512c