INFO: task syz.0.1279:8664 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.0.1279 state:D stack:0 pid:8664 tgid:8664 ppid:7587 task_flags:0x400040 flags:0x00000005 Call trace: [<81b54d5c>] (__schedule) from [<81b561f4>] (__schedule_loop kernel/sched/core.c:7307 [inline]) [<81b54d5c>] (__schedule) from [<81b561f4>] (schedule+0x2c/0x134 kernel/sched/core.c:7322) r10:86a1fb00 r9:8399bd40 r8:86747f00 r7:8589e608 r6:ebc6dea0 r5:ebc6de30 r4:8399bd40 [<81b561c8>] (schedule) from [<8079cd7c>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b561c8>] (schedule) from [<8079cd7c>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b561c8>] (schedule) from [<8079cd7c>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:ebc6de30 r4:8589e5b0 [<8079c9ec>] (fuse_chan_send) from [<807af2e4>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:8687ee00 r7:8621e7c0 r6:8383e700 r5:86209780 r4:ebc6dea0 [<807af288>] (__fuse_simple_request) from [<807a4a80>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807af288>] (__fuse_simple_request) from [<807a4a80>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:504) r5:834b1680 r4:86a1fb00 [<807a4908>] (fuse_flush) from [<8059912c>] (filp_flush+0x38/0x88 fs/open.c:1471) r8:8383e740 r7:830eb9c0 r6:0000001e r5:8383e700 r4:86a1fb00 [<805990f4>] (filp_flush) from [<80599190>] (filp_close+0x14/0x28 fs/open.c:1484) r7:830eb9c0 r6:0000001e r5:86a1fb00 r4:8383e700 [<8059917c>] (filp_close) from [<805cb6b4>] (__range_close fs/file.c:793 [inline]) [<8059917c>] (filp_close) from [<805cb6b4>] (__do_sys_close_range fs/file.c:854 [inline]) [<8059917c>] (filp_close) from [<805cb6b4>] (sys_close_range+0x18c/0x224 fs/file.c:818) r5:00000007 r4:8383e700 [<805cb528>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xebc6dfa8 to 0xebc6dff0) dfa0: 00000000 00000000 00000003 0000001e 00000000 7efc8918 dfc0: 00000000 00000000 00000000 000001b4 000ed24b ffffffff 00000000 003462e4 dfe0: 7efc8840 7efc8830 0002853c 00130820 r10:000001b4 r9:8399bd40 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) r7:60000093 r6:60000093 r5:82331450 r4:00000000 [<80201a74>] (show_stack) from [<8021e578>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201a74>] (show_stack) from [<8021e578>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e51c>] (dump_stack_lvl) from [<8021e5a4>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000013 r5:00000001 r4:00000001 [<8021e58c>] (dump_stack) from [<81b3e3fc>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b3e2ac>] (nmi_cpu_backtrace) from [<81b3e550>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83320c40 r5:82a1c7b8 r4:ffffffff [<81b3e41c>] (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 [<81b4608c>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4608c>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4608c>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b46024>] (sys_info) from [<8038f884>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b46024>] (sys_info) from [<8038f884>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007f2b r4:0000000a [<8038f4e4>] (watchdog) from [<802816f8>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:831d5600 r7:00000000 r6:8038f4e4 r5:83320c40 r4:833e1140 [<802815dc>] (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 r5:802815dc r4:833e1140 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11366 Comm: syz.3.1947 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at uaccess_save_and_enable arch/arm/include/asm/uaccess.h:59 [inline] PC is at ____sys_recvmsg+0x108/0x184 net/socket.c:2925 LR is at ____sys_recvmsg+0xe4/0x184 net/socket.c:2917 pc : [<8161d528>] lr : [<8161d504>] psr: 60000013 sp : dfcc1d48 ip : a1021efb fp : dfcc1e04 r10: dfcc1d54 r9 : 00000002 r8 : 00000000 r7 : 00000000 r6 : b5003500 r5 : 20021ee0 r4 : dfcc1ee8 r3 : b5403587 r2 : 00000000 r1 : 7effffff r0 : 20021ef4 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 86de4f00 DAC: fffffffd Call trace: [<8161d420>] (____sys_recvmsg) from [<8161ec34>] (___sys_recvmsg+0x88/0xbc net/socket.c:2946) r10:00010106 r9:84ef8000 r8:83499940 r7:00000002 r6:20021ee0 r5:dfcc1ee8 r4:00000000 [<8161ebac>] (___sys_recvmsg) from [<8161ed88>] (do_recvmmsg+0x120/0x2f4 net/socket.c:3041) r8:00000000 r7:00000002 r6:000010f1 r5:20021ee0 r4:dfcc1ec8 [<8161ec68>] (do_recvmmsg) from [<81621354>] (__sys_recvmmsg net/socket.c:3115 [inline]) [<8161ec68>] (do_recvmmsg) from [<81621354>] (__do_sys_recvmmsg_time32 net/socket.c:3149 [inline]) [<8161ec68>] (do_recvmmsg) from [<81621354>] (sys_recvmmsg_time32+0xc4/0xd8 net/socket.c:3142) r10:0000016d r9:84ef8000 r8:00010106 r7:00000002 r6:00000000 r5:200000c0 r4:00000003 [<81621290>] (sys_recvmmsg_time32) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfcc1fa8 to 0xdfcc1ff0) 1fa0: 00000000 00000000 00000003 200000c0 00010106 00000002 1fc0: 00000000 00000000 003463b8 0000016d 00346378 00000000 003d0f00 76f990dc 1fe0: 76f98e88 76f98e78 00018ebc 00130820 r8:8020029c r7:0000016d r6:003463b8 r5:00000000 r4:00000000