INFO: task syz.0.1180:7868 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.0.1180 state:D stack:0 pid:7868 tgid:7857 ppid:3103 task_flags:0x400040 flags:0x00000001 Call trace: [<81b5c2fc>] (__schedule) from [<81b5d794>] (__schedule_loop kernel/sched/core.c:7311 [inline]) [<81b5c2fc>] (__schedule) from [<81b5d794>] (schedule+0x2c/0xec kernel/sched/core.c:7326) r10:86478e00 r9:86478d80 r8:8643ab00 r7:84917a68 r6:ecae9cc0 r5:ecae9c58 r4:83311880 [<81b5d768>] (schedule) from [<8079fbe0>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b5d768>] (schedule) from [<8079fbe0>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b5d768>] (schedule) from [<8079fbe0>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:ecae9c58 r4:84917a10 [<8079f850>] (fuse_chan_send) from [<807b2138>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:84ee4d80 r7:00000000 r6:00000000 r5:84ee4d80 r4:ecae9cc0 [<807b20dc>] (__fuse_simple_request) from [<807a6d20>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807b20dc>] (__fuse_simple_request) from [<807a6d20>] (fuse_send_open fs/fuse/file.c:51 [inline]) [<807b20dc>] (__fuse_simple_request) from [<807a6d20>] (fuse_file_open+0x188/0x23c fs/fuse/file.c:162) r5:00000001 r4:864468c0 [<807a6b98>] (fuse_file_open) from [<807a6f30>] (fuse_do_open fs/fuse/file.c:192 [inline]) [<807a6b98>] (fuse_file_open) from [<807a6f30>] (fuse_open+0x84/0x2fc fs/fuse/file.c:281) r10:834a46e8 r9:864468c0 r8:00000000 r7:864d2080 r6:00000000 r5:00000000 r4:8592bd40 [<807a6eac>] (fuse_open) from [<80599ff0>] (do_dentry_open+0x138/0x50c fs/open.c:947) r10:834a46e8 r9:864d2080 r8:864d20a8 r7:807a6eac r6:8592bd40 r5:00000000 r4:864d2080 [<80599eb8>] (do_dentry_open) from [<8059b9c8>] (vfs_open+0x2c/0xe8 fs/open.c:1052) r9:864d2080 r8:ecae9e58 r7:ecae9f20 r6:864d20a8 r5:82b21e14 r4:864d2080 [<8059b99c>] (vfs_open) from [<805b66a4>] (do_open fs/namei.c:4700 [inline]) [<8059b99c>] (vfs_open) from [<805b66a4>] (path_openat+0x850/0x1260 fs/namei.c:4863) r6:00000000 r5:82b21e14 r4:00022801 [<805b5e54>] (path_openat) from [<805b716c>] (do_file_open+0xb8/0x150 fs/namei.c:4892) r10:00000142 r9:83311880 r8:00000001 r7:ffffff9c r6:ecae9f20 r5:83311880 r4:838460c0 [<805b70b4>] (do_file_open) from [<8059beb4>] (do_sys_openat2+0x8c/0xf0 fs/open.c:1368) r8:8020029c r7:20000380 r6:ffffff9c r5:838460c0 r4:00000004 [<8059be28>] (do_sys_openat2) from [<8059c3cc>] (do_sys_open fs/open.c:1374 [inline]) [<8059be28>] (do_sys_openat2) from [<8059c3cc>] (__do_sys_openat fs/open.c:1390 [inline]) [<8059be28>] (do_sys_openat2) from [<8059c3cc>] (sys_openat+0x88/0xd8 fs/open.c:1385) r7:00000142 r6:003563b4 r5:20000380 r4:ffffff9c [<8059c344>] (sys_openat) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xecae9fa8 to 0xecae9ff0) 9fa0: 00000000 00000000 ffffff9c 20000380 00022801 00000000 9fc0: 00000000 00000000 003563b4 00000142 00356378 00000000 003d0f00 76f820dc 9fe0: 76f81e88 76f81e78 00018ebc 001308d0 r5:00000000 r4:00000000 NMI backtrace for cpu 0 CPU: 0 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 r5:82332b58 r4:00000000 [<80201a74>] (show_stack) from [<8021e580>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201a74>] (show_stack) from [<8021e580>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e524>] (dump_stack_lvl) from [<8021e5ac>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000113 r5:00000000 r4:00000001 [<8021e594>] (dump_stack) from [<81b4599c>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b4584c>] (nmi_cpu_backtrace) from [<81b45af0>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83178000 r5:82a1c7b8 r4:ffffffff [<81b459bc>] (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 r5:00007f2b r4:00000048 [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4d62c>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4d62c>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4d62c>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b4d5c4>] (sys_info) from [<8038f838>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b4d5c4>] (sys_info) from [<8038f838>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007f2b r4:0000000a [<8038f498>] (watchdog) from [<80281710>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:83110980 r7:00000000 r6:8038f498 r5:83178000 r4:8387c5c0 [<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 r4:8387c5c0 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2822 Comm: pr/ttyAMA-1 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 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] LR is at __uart_port_unlock_irqrestore include/linux/serial_core.h:618 [inline] LR is at pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2700 pc : [<81b66c5c>] lr : [<80b01d34>] psr: 60000013 sp : eb401ec8 ip : eb401ed8 fp : eb401ed4 r10: 82b5cd1c r9 : 00000001 r8 : 00000000 r7 : 00000117 r6 : 82b5cc80 r5 : 00000000 r4 : 00000001 r3 : 000010db r2 : 00000000 r1 : 60000013 r0 : 845f1c40 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 86d67e00 DAC: 00000000 Call trace: [<81b66c34>] (_raw_spin_unlock_irqrestore) from [<80b01d34>] (spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]) [<81b66c34>] (_raw_spin_unlock_irqrestore) from [<80b01d34>] (__uart_port_unlock_irqrestore include/linux/serial_core.h:618 [inline]) [<81b66c34>] (_raw_spin_unlock_irqrestore) from [<80b01d34>] (pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2700) [<80b01d14>] (pl011_console_device_unlock) from [<802ec168>] (nbcon_emit_one+0x88/0x100 kernel/printk/nbcon.c:1165) [<802ec0e0>] (nbcon_emit_one) from [<802ec3e8>] (nbcon_kthread_func+0x208/0x2ec kernel/printk/nbcon.c:1271) r6:82cc72ec r5:82b5cc80 r4:847555c0 [<802ec1e0>] (nbcon_kthread_func) from [<80281710>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df92db38 r8:84ded300 r7:82b5cc80 r6:802ec1e0 r5:847555c0 r4:838db580 [<802815f4>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xeb401fb0 to 0xeb401ff8) 1fa0: 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802815f4 r4:838db580