INFO: task syz.3.3064:15385 blocked for more than 430 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3064 state:D stack:0 pid:15385 tgid:15382 ppid:14934 task_flags:0x400040 flags:0x00000001 Call trace: [<81a3dedc>] (__schedule) from [<802972f4>] (__schedule_loop kernel/sched/core.c:7043 [inline]) [<81a3dedc>] (__schedule) from [<802972f4>] (rt_mutex_schedule+0x20/0x38 kernel/sched/core.c:7339) r10:83c20000 r9:00000002 r8:00000000 r7:df9f9d98 r6:df9f9da0 r5:83ae2400 r4:83ae2400 [<802972d4>] (rt_mutex_schedule) from [<81a44d58>] (rt_mutex_slowlock_block.constprop.0+0x40/0x1d4 kernel/locking/rtmutex.c:1647) r5:83ae2400 r4:8325dc54 [<81a44d18>] (rt_mutex_slowlock_block.constprop.0) from [<81a460b0>] (__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]) [<81a44d18>] (rt_mutex_slowlock_block.constprop.0) from [<81a460b0>] (__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]) [<81a44d18>] (rt_mutex_slowlock_block.constprop.0) from [<81a460b0>] (rt_mutex_slowlock.constprop.0+0xd4/0x364 kernel/locking/rtmutex.c:1800) r10:60000013 r9:df9f9da0 r8:00000002 r7:df9f9d98 r6:8325dc54 r5:00000000 r4:83ae2400 [<81a45fdc>] (rt_mutex_slowlock.constprop.0) from [<81a46424>] (__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]) [<81a45fdc>] (rt_mutex_slowlock.constprop.0) from [<81a46424>] (__rt_mutex_lock_common kernel/locking/rtmutex_api.c:49 [inline]) [<81a45fdc>] (rt_mutex_slowlock.constprop.0) from [<81a46424>] (rt_mutex_lock+0x44/0x48 kernel/locking/rtmutex_api.c:89) r10:83ae2400 r9:00000007 r8:00000000 r7:00000007 r6:00000000 r5:00000001 r4:8325dc40 [<81a463e0>] (rt_mutex_lock) from [<810ccae8>] (i2c_adapter_lock_bus+0x14/0x18 drivers/i2c/i2c-core-base.c:852) [<810ccad4>] (i2c_adapter_lock_bus) from [<810d22f8>] (i2c_lock_bus include/linux/i2c.h:809 [inline]) [<810ccad4>] (i2c_adapter_lock_bus) from [<810d22f8>] (__i2c_lock_bus_helper drivers/i2c/i2c-core.h:46 [inline]) [<810ccad4>] (i2c_adapter_lock_bus) from [<810d22f8>] (i2c_smbus_xfer+0xa4/0x12c drivers/i2c/i2c-core-smbus.c:542) [<810d2254>] (i2c_smbus_xfer) from [<810d4174>] (i2cdev_ioctl_smbus+0xf4/0x384 drivers/i2c/i2c-dev.c:389) r8:00000022 r7:20000180 r6:00000001 r5:859a6400 r4:00000005 [<810d4080>] (i2cdev_ioctl_smbus) from [<810d470c>] (i2cdev_ioctl+0x308/0x404 drivers/i2c/i2c-dev.c:478) r10:83ae2400 r9:00000004 r8:854f9240 r7:20001600 r6:b5403587 r5:859a6400 r4:20001600 [<810d4404>] (i2cdev_ioctl) from [<8056d0cc>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<810d4404>] (i2cdev_ioctl) from [<8056d0cc>] (do_vfs_ioctl fs/ioctl.c:552 [inline]) [<810d4404>] (i2cdev_ioctl) from [<8056d0cc>] (__do_sys_ioctl fs/ioctl.c:596 [inline]) [<810d4404>] (i2cdev_ioctl) from [<8056d0cc>] (sys_ioctl+0x130/0xba0 fs/ioctl.c:584) r6:854f9241 r5:00000000 r4:00000720 [<8056cf9c>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf9f9fa8 to 0xdf9f9ff0) 9fa0: 00000000 00000000 00000004 00000720 20001600 00000000 9fc0: 00000000 00000000 00306308 00000036 002f0000 00000000 00006364 76fcf0bc 9fe0: 76fceec0 76fceeb0 0001948c 001322a0 r10:00000036 r9:83ae2400 r8:8020029c r7:00000036 r6:00306308 r5:00000000 r4:00000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT Hardware name: ARM-Versatile Express Call trace: [<80201a24>] (dump_backtrace) from [<80201b20>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:00000000 r6:00000113 r5:60000193 r4:82260e34 [<80201b08>] (show_stack) from [<8021fc60>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201b08>] (show_stack) from [<8021fc60>] (dump_stack_lvl+0x70/0x7c lib/dump_stack.c:120) [<8021fbf0>] (dump_stack_lvl) from [<8021fc84>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r5:00000001 r4:00000001 [<8021fc6c>] (dump_stack) from [<81a27af0>] (nmi_cpu_backtrace+0x160/0x17c lib/nmi_backtrace.c:113) [<81a27990>] (nmi_cpu_backtrace) from [<81a27c3c>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62) r7:00000001 r6:8280c690 r5:8281ac94 r4:ffffffff [<81a27b0c>] (nmi_trigger_cpumask_backtrace) from [<802304fc>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:852) r9:82abd56c r8:82804d40 r7:0002b400 r6:00007f1a r5:8281b248 r4:854ca90c [<802304e4>] (arch_trigger_cpumask_backtrace) from [<8037d958>] (trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]) [<802304e4>] (arch_trigger_cpumask_backtrace) from [<8037d958>] (check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]) [<802304e4>] (arch_trigger_cpumask_backtrace) from [<8037d958>] (watchdog+0x4d4/0x81c kernel/hung_task.c:491) [<8037d484>] (watchdog) from [<80281fcc>] (kthread+0x12c/0x280 kernel/kthread.c:463) r10:00000000 r9:00000000 r8:8037d484 r7:833c1680 r6:833c1680 r5:8321e000 r4:00000001 [<80281ea0>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xdf8e1fb0 to 0xdf8e1ff8) 1fa0: 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80281ea0 r4:833c0a00 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2846 Comm: pr/ttyAMA-1 Not tainted syzkaller #0 PREEMPT Hardware name: ARM-Versatile Express PC is at __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] PC is at _raw_spin_unlock_irqrestore+0x28/0x54 kernel/locking/spinlock.c:194 LR is at spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] LR is at __uart_port_unlock_irqrestore include/linux/serial_core.h:616 [inline] LR is at pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2603 pc : [<81a47ea4>] lr : [<80a79fc8>] psr: 60000113 sp : eb879eb0 ip : eb879ec0 fp : eb879ebc r10: 82959154 r9 : 00000000 r8 : 00000000 r7 : 00000117 r6 : 829590b8 r5 : 00000000 r4 : 00000001 r3 : 000035fb r2 : 00000000 r1 : 60000113 r0 : 84310840 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 86130ac0 DAC: fffffffd Call trace: [<81a47e7c>] (_raw_spin_unlock_irqrestore) from [<80a79fc8>] (spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]) [<81a47e7c>] (_raw_spin_unlock_irqrestore) from [<80a79fc8>] (__uart_port_unlock_irqrestore include/linux/serial_core.h:616 [inline]) [<81a47e7c>] (_raw_spin_unlock_irqrestore) from [<80a79fc8>] (pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2603) [<80a79fa8>] (pl011_console_device_unlock) from [<802e456c>] (nbcon_emit_one+0x88/0x100 kernel/printk/nbcon.c:1142) [<802e44e4>] (nbcon_emit_one) from [<802e478c>] (nbcon_kthread_func+0x1a8/0x2a4 kernel/printk/nbcon.c:1229) r6:8280c690 r5:84c1bc00 r4:829590b8 [<802e45e4>] (nbcon_kthread_func) from [<80281fcc>] (kthread+0x12c/0x280 kernel/kthread.c:463) r10:00000000 r9:829590b8 r8:802e45e4 r7:8419d980 r6:8419d980 r5:84c1bc00 r4:00000001 [<80281ea0>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xeb879fb0 to 0xeb879ff8) 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 r5:80281ea0 r4:838ff300