INFO: task syz.8.5313:25796 blocked for more than 430 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.5313 state:D stack:0 pid:25796 tgid:25795 ppid:25209 task_flags:0x400040 flags:0x00000001 Call trace: [<81aa9c1c>] (__schedule) from [<80296488>] (__schedule_loop kernel/sched/core.c:6949 [inline]) [<81aa9c1c>] (__schedule) from [<80296488>] (rt_mutex_schedule+0x20/0x38 kernel/sched/core.c:7245) r10:00000000 r9:833c4800 r8:dfa3dde0 r7:dfa3dde8 r6:833c4800 r5:8666a400 r4:8666a400 [<80296468>] (rt_mutex_schedule) from [<81ab18b0>] (rt_mutex_slowlock_block.constprop.0+0x16c/0x1e4 kernel/locking/rtmutex.c:1647) r5:8666a400 r4:83323854 [<81ab1744>] (rt_mutex_slowlock_block.constprop.0) from [<81ab2cd0>] (__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]) [<81ab1744>] (rt_mutex_slowlock_block.constprop.0) from [<81ab2cd0>] (__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]) [<81ab1744>] (rt_mutex_slowlock_block.constprop.0) from [<81ab2cd0>] (rt_mutex_slowlock.constprop.0+0xcc/0x370 kernel/locking/rtmutex.c:1800) r10:85a61000 r9:60000013 r8:dfa3dde8 r7:dfa3dde0 r6:00000002 r5:83323854 r4:8666a400 [<81ab2c04>] (rt_mutex_slowlock.constprop.0) from [<81ab3058>] (__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]) [<81ab2c04>] (rt_mutex_slowlock.constprop.0) from [<81ab3058>] (__rt_mutex_lock_common kernel/locking/rtmutex_api.c:49 [inline]) [<81ab2c04>] (rt_mutex_slowlock.constprop.0) from [<81ab3058>] (rt_mutex_lock+0x44/0x48 kernel/locking/rtmutex_api.c:89) r10:85a61000 r9:00000001 r8:86e51f00 r7:85ef22c0 r6:86e51f00 r5:00000001 r4:83323840 [<81ab3014>] (rt_mutex_lock) from [<81115b48>] (i2c_adapter_lock_bus+0x14/0x18 drivers/i2c/i2c-core-base.c:849) [<81115b34>] (i2c_adapter_lock_bus) from [<81117a94>] (i2c_lock_bus include/linux/i2c.h:809 [inline]) [<81115b34>] (i2c_adapter_lock_bus) from [<81117a94>] (__i2c_lock_bus_helper drivers/i2c/i2c-core.h:46 [inline]) [<81115b34>] (i2c_adapter_lock_bus) from [<81117a94>] (i2c_transfer+0xc8/0x108 drivers/i2c/i2c-core-base.c:2313) [<811179cc>] (i2c_transfer) from [<8111cfb4>] (i2cdev_ioctl_rdwr+0x140/0x238 drivers/i2c/i2c-dev.c:306) r6:00000001 r5:0000000c r4:86e51f0c [<8111ce74>] (i2cdev_ioctl_rdwr) from [<8111d828>] (i2cdev_ioctl+0x284/0x3ac drivers/i2c/i2c-dev.c:467) r10:8666a400 r9:00000004 r8:868ccc00 r7:200005c0 r6:85a61000 r5:86e51f00 r4:200005c0 [<8111d5a4>] (i2cdev_ioctl) from [<80582278>] (vfs_ioctl fs/ioctl.c:51 [inline]) [<8111d5a4>] (i2cdev_ioctl) from [<80582278>] (do_vfs_ioctl fs/ioctl.c:551 [inline]) [<8111d5a4>] (i2cdev_ioctl) from [<80582278>] (__do_sys_ioctl fs/ioctl.c:595 [inline]) [<8111d5a4>] (i2cdev_ioctl) from [<80582278>] (sys_ioctl+0x244/0xb58 fs/ioctl.c:583) r7:200005c0 r6:00000707 r5:868ccc01 r4:00000000 [<80582034>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfa3dfa8 to 0xdfa3dff0) dfa0: 00000000 00000000 00000004 00000707 200005c0 00000000 dfc0: 00000000 00000000 00346310 00000036 003462d8 00000000 00000001 76f890dc dfe0: 76f88e88 76f88e78 00018734 0012fc20 r10:00000036 r9:8666a400 r8:8020029c r7:00000036 r6:00346310 r5:00000000 r4:00000000 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT 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 r5:822a269c r4:00000000 [<80201b1c>] (show_stack) from [<8021ed9c>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201b1c>] (show_stack) from [<8021ed9c>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021ed40>] (dump_stack_lvl) from [<8021edc8>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000113 r5:00000001 r4:00000001 [<8021edb0>] (dump_stack) from [<81a9385c>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:113) [<81a9370c>] (nmi_cpu_backtrace) from [<81a939ac>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62) r7:00000001 r6:8280c510 r5:8281ad9c r4:ffffffff [<81a9387c>] (nmi_trigger_cpumask_backtrace) from [<8022fe60>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:852) r9:82ac382c r8:8280c690 r7:82804d80 r6:8666abf0 r5:00007ec8 r4:00000048 [<8022fe48>] (arch_trigger_cpumask_backtrace) from [<81a9b490>] (trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]) [<8022fe48>] (arch_trigger_cpumask_backtrace) from [<81a9b490>] (__sys_info lib/sys_info.c:157 [inline]) [<8022fe48>] (arch_trigger_cpumask_backtrace) from [<81a9b490>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81a9b428>] (sys_info) from [<80382f6c>] (check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]) [<81a9b428>] (sys_info) from [<80382f6c>] (watchdog+0x458/0x888 kernel/hung_task.c:515) r5:00007ec8 r4:8723ac0c [<80382b14>] (watchdog) from [<8027facc>] (kthread+0x128/0x27c kernel/kthread.c:463) r10:00000000 r9:00000000 r8:80382b14 r7:832d4180 r6:832d4180 r5:832e2400 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 r4:838c6500 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2906 Comm: klogd Not tainted syzkaller #0 PREEMPT Hardware name: ARM-Versatile Express PC is at uaccess_restore arch/arm/include/asm/uaccess.h:67 [inline] PC is at raw_copy_to_user arch/arm/include/asm/uaccess.h:583 [inline] PC is at _inline_copy_to_user include/linux/uaccess.h:206 [inline] PC is at copy_to_user include/linux/uaccess.h:234 [inline] PC is at syslog_print+0x238/0x3b8 kernel/printk/printk.c:1660 LR is at 0x31303030 pc : [<802e0644>] lr : [<31303030>] psr: 80030113 sp : eb8f1e38 ip : 00000018 fp : eb8f1efc r10: 82a7f280 r9 : 00000089 r8 : 00000000 r7 : 76fb6140 r6 : 000003ff r5 : 82a7f4e0 r4 : 00000000 r3 : b5403587 r2 : 80000000 r1 : 86f8d889 r0 : 00000000 Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 84cd9480 DAC: fffffffd Call trace: [<802e040c>] (syslog_print) from [<802e0c94>] (do_syslog+0x14c/0x37c kernel/printk/printk.c:1761) r10:00000067 r9:83f1b000 r8:76fb6140 r7:000003ff r6:00000000 r5:00000000 r4:00000002 [<802e0b48>] (do_syslog) from [<802e0ed8>] (__do_sys_syslog kernel/printk/printk.c:1853 [inline]) [<802e0b48>] (do_syslog) from [<802e0ed8>] (sys_syslog+0x14/0x18 kernel/printk/printk.c:1851) r9:83f1b000 r8:8020029c r7:00000067 r6:00000000 r5:76fb61a4 r4:76fb6140 [<802e0ec4>] (sys_syslog) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xeb8f1fa8 to 0xeb8f1ff0) 1fa0: 76fb6140 76fb61a4 00000002 76fb6140 000003ff 76fb6140 1fc0: 76fb6140 76fb61a4 00000000 00000067 00000000 76fb5904 76fb6554 76f953bc 1fe0: 76fb5cdc 7ed54c94 76f392c8 76e5b3ec