INFO: task syz.5.6045:30290 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.5.6045 state:D stack:0 pid:30290 tgid:30289 ppid:29325 task_flags:0x400040 flags:0x00000001 Call trace: [<81aa9834>] (__schedule) from [<80296488>] (__schedule_loop kernel/sched/core.c:6949 [inline]) [<81aa9834>] (__schedule) from [<80296488>] (rt_mutex_schedule+0x20/0x38 kernel/sched/core.c:7245) r10:00000000 r9:86541800 r8:df9e1dd0 r7:df9e1dd8 r6:86541800 r5:86542400 r4:86542400 [<80296468>] (rt_mutex_schedule) from [<81ab14c8>] (rt_mutex_slowlock_block.constprop.0+0x16c/0x1e4 kernel/locking/rtmutex.c:1647) r5:86542400 r4:833b2854 [<81ab135c>] (rt_mutex_slowlock_block.constprop.0) from [<81ab28e8>] (__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]) [<81ab135c>] (rt_mutex_slowlock_block.constprop.0) from [<81ab28e8>] (__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]) [<81ab135c>] (rt_mutex_slowlock_block.constprop.0) from [<81ab28e8>] (rt_mutex_slowlock.constprop.0+0xcc/0x370 kernel/locking/rtmutex.c:1800) r10:81dea3b8 r9:60000013 r8:df9e1dd8 r7:df9e1dd0 r6:00000002 r5:833b2854 r4:86542400 [<81ab281c>] (rt_mutex_slowlock.constprop.0) from [<81ab2c70>] (__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]) [<81ab281c>] (rt_mutex_slowlock.constprop.0) from [<81ab2c70>] (__rt_mutex_lock_common kernel/locking/rtmutex_api.c:49 [inline]) [<81ab281c>] (rt_mutex_slowlock.constprop.0) from [<81ab2c70>] (rt_mutex_lock+0x44/0x48 kernel/locking/rtmutex_api.c:89) r10:81dea3b8 r9:86542400 r8:8111c81c r7:00000000 r6:df9e1e98 r5:00000001 r4:833b2840 [<81ab2c2c>] (rt_mutex_lock) from [<81115948>] (i2c_adapter_lock_bus+0x14/0x18 drivers/i2c/i2c-core-base.c:849) [<81115934>] (i2c_adapter_lock_bus) from [<81117894>] (i2c_lock_bus include/linux/i2c.h:809 [inline]) [<81115934>] (i2c_adapter_lock_bus) from [<81117894>] (__i2c_lock_bus_helper drivers/i2c/i2c-core.h:46 [inline]) [<81115934>] (i2c_adapter_lock_bus) from [<81117894>] (i2c_transfer+0xc8/0x108 drivers/i2c/i2c-core-base.c:2313) [<811177cc>] (i2c_transfer) from [<81117930>] (i2c_transfer_buffer_flags+0x5c/0x8c drivers/i2c/i2c-core-base.c:2345) r6:00000000 r5:00000010 r4:00000000 [<811178d4>] (i2c_transfer_buffer_flags) from [<8111c88c>] (i2c_master_send include/linux/i2c.h:109 [inline]) [<811178d4>] (i2c_transfer_buffer_flags) from [<8111c88c>] (i2cdev_write+0x70/0xc8 drivers/i2c/i2c-dev.c:183) r7:8608d400 r6:86d1bcc0 r5:00000010 r4:00000000 [<8111c81c>] (i2cdev_write) from [<805674c4>] (vfs_write fs/read_write.c:684 [inline]) [<8111c81c>] (i2cdev_write) from [<805674c4>] (vfs_write+0xd4/0x450 fs/read_write.c:666) r7:df9e1f78 r6:00000000 r5:86d1bcc0 r4:00000000 [<805673f0>] (vfs_write) from [<80567cb8>] (ksys_pwrite64 fs/read_write.c:793 [inline]) [<805673f0>] (vfs_write) from [<80567cb8>] (__do_sys_pwrite64 fs/read_write.c:801 [inline]) [<805673f0>] (vfs_write) from [<80567cb8>] (sys_pwrite64+0xa0/0xc8 fs/read_write.c:798) r10:000000b5 r9:86542400 r8:8020029c r7:00000000 r6:86d1bcc0 r5:00000000 r4:86d1bcc1 [<80567c18>] (sys_pwrite64) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf9e1fa8 to 0xdf9e1ff0) 1fa0: 00000000 00000000 00000007 00000000 00000000 00000009 1fc0: 00000000 00000000 00346314 000000b5 003462d8 00000000 00000001 76f440dc 1fe0: 76f43e88 76f43e78 00018734 0012fc20 r7:000000b5 r6:00346314 r5:00000000 r4:00000000 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express Call trace: [<80201a40>] (dump_backtrace) from [<80201b34>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:60000193 r6:60000193 r5:822a20d0 r4:00000000 [<80201b1c>] (show_stack) from [<8021ed6c>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201b1c>] (show_stack) from [<8021ed6c>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021ed10>] (dump_stack_lvl) from [<8021ed98>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000113 r5:00000000 r4:00000001 [<8021ed80>] (dump_stack) from [<81a93470>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:113) [<81a93320>] (nmi_cpu_backtrace) from [<81a935c0>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62) r7:00000000 r6:8280c510 r5:8281ad5c r4:ffffffff [<81a93490>] (nmi_trigger_cpumask_backtrace) from [<8022fe60>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:852) r9:82ac382c r8:8280c690 r7:82804d80 r6:86542bf0 r5:00007efc r4:00000048 [<8022fe48>] (arch_trigger_cpumask_backtrace) from [<81a9b0a4>] (trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]) [<8022fe48>] (arch_trigger_cpumask_backtrace) from [<81a9b0a4>] (__sys_info lib/sys_info.c:157 [inline]) [<8022fe48>] (arch_trigger_cpumask_backtrace) from [<81a9b0a4>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81a9b03c>] (sys_info) from [<80382fc4>] (check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]) [<81a9b03c>] (sys_info) from [<80382fc4>] (watchdog+0x458/0x888 kernel/hung_task.c:515) r5:00007efc r4:86b1a90c [<80382b6c>] (watchdog) from [<8027facc>] (kthread+0x128/0x27c kernel/kthread.c:463) r10:00000000 r9:00000000 r8:80382b6c r7:830d5880 r6:830d5880 r5:8321ec00 r4:00000001 [<8027f9a4>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xdf8d9fb0 to 0xdf8d9ff8) 9fa0: 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:8027f9a4 r4:832c3f40 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2813 Comm: pr/ttyAMA-1 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at dequeue_skb net/sched/sch_generic.c:298 [inline] PC is at qdisc_restart net/sched/sch_generic.c:402 [inline] PC is at __qdisc_run+0x90/0x804 net/sched/sch_generic.c:420 LR is at __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] LR is at _raw_spin_unlock_irqrestore+0x30/0x54 kernel/locking/spinlock.c:194 pc : [<81645fa0>] lr : [<81ab4710>] psr: 20000113 sp : df805ea8 ip : df805dc8 fp : df805ef4 r10: 00000040 r9 : 85e81090 r8 : 85e81054 r7 : 00000001 r6 : 00000000 r5 : ddde5000 r4 : 85e81000 r3 : 00c7b698 r2 : 00000101 r1 : 20000113 r0 : 00000000 Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 86c582c0 DAC: 00000000 Call trace: frame pointer underflow [<81645f10>] (__qdisc_run) from [<815ba0bc>] (qdisc_run include/net/pkt_sched.h:120 [inline]) [<81645f10>] (__qdisc_run) from [<815ba0bc>] (qdisc_run include/net/pkt_sched.h:117 [inline]) [<81645f10>] (__qdisc_run) from [<815ba0bc>] (net_tx_action+0x13c/0x40c net/core/dev.c:5796) r10:00000004 r9:85e81090 r8:85e8108c r7:00000001 r6:00000000 r5:ddde5000 r4:85e81000 [<815b9f80>] (net_tx_action) from [<8025b428>] (handle_softirqs+0x15c/0x468 kernel/softirq.c:622) r10:00000004 r9:8504ec00 r8:00000100 r7:00000008 r6:00000002 r5:00000003 r4:82804088 [<8025b2cc>] (handle_softirqs) from [<8025b8d0>] (__do_softirq kernel/softirq.c:656 [inline]) [<8025b2cc>] (handle_softirqs) from [<8025b8d0>] (invoke_softirq kernel/softirq.c:496 [inline]) [<8025b2cc>] (handle_softirqs) from [<8025b8d0>] (__irq_exit_rcu+0x150/0x1d0 kernel/softirq.c:723) r10:829596dc r9:8504ec00 r8:00000000 r7:eb04dea8 r6:8244e52c r5:82489098 r4:8504ec00 [<8025b780>] (__irq_exit_rcu) from [<8025bc08>] (irq_exit+0x10/0x18 kernel/softirq.c:751) r5:82489098 r4:826c2a9c [<8025bbf8>] (irq_exit) from [<81aa60c0>] (generic_handle_arch_irq+0x7c/0x80 kernel/irq/handle.c:295) [<81aa6044>] (generic_handle_arch_irq) from [<81a753ec>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40) r9:8504ec00 r8:00000000 r7:eb04dedc r6:ffffffff r5:60000113 r4:802e081c [<81a753d0>] (call_with_stack) from [<80200bec>] (__irq_svc+0x8c/0xbc arch/arm/kernel/entry-armv.S:228) Exception stack(0xeb04dea8 to 0xeb04def0) dea0: 00000000 00000000 00000000 8504ec00 8504ec00 82959640 dec0: 82ac0104 00000001 00000000 00000001 829596dc eb04df6c eb04deb0 eb04def8 dee0: 802e5394 802e081c 60000113 ffffffff [<802e5180>] (nbcon_kthread_func) from [<8027facc>] (kthread+0x128/0x27c kernel/kthread.c:463) r10:00000000 r9:82959640 r8:802e5180 r7:84a8e780 r6:84a8e780 r5:8504ec00 r4:00000001 [<8027f9a4>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xeb04dfb0 to 0xeb04dff8) dfa0: 00000000 00000000 00000000 00000000 dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:8027f9a4 r4:83884540