INFO: task syz.3.37547:18795 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.3.37547 state:D stack:0 pid:18795 tgid:18795 ppid:27610 task_flags:0x400040 flags:0x00000005 Call trace: [<81b58f5c>] (__schedule) from [<81b5a3f4>] (__schedule_loop kernel/sched/core.c:7311 [inline]) [<81b58f5c>] (__schedule) from [<81b5a3f4>] (schedule+0x2c/0xec kernel/sched/core.c:7326) r10:86069080 r9:84856200 r8:8643bd00 r7:85149c98 r6:ed801ea0 r5:ed801e30 r4:84856200 [<81b5a3c8>] (schedule) from [<8079f0e0>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b5a3c8>] (schedule) from [<8079f0e0>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b5a3c8>] (schedule) from [<8079f0e0>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:ed801e30 r4:85149c40 [<8079ed50>] (fuse_chan_send) from [<807b1638>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:830be800 r7:86475bc0 r6:8648f200 r5:867d5900 r4:ed801ea0 [<807b15dc>] (__fuse_simple_request) from [<807a6dd4>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807b15dc>] (__fuse_simple_request) from [<807a6dd4>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:504) r5:85c59440 r4:86069080 [<807a6c5c>] (fuse_flush) from [<80599334>] (filp_flush+0x38/0x88 fs/open.c:1471) r8:8648f240 r7:864e7f80 r6:0000001e r5:8648f200 r4:86069080 [<805992fc>] (filp_flush) from [<80599398>] (filp_close+0x14/0x28 fs/open.c:1484) r7:864e7f80 r6:0000001e r5:86069080 r4:8648f200 [<80599384>] (filp_close) from [<805cb940>] (__range_close fs/file.c:793 [inline]) [<80599384>] (filp_close) from [<805cb940>] (__do_sys_close_range fs/file.c:854 [inline]) [<80599384>] (filp_close) from [<805cb940>] (sys_close_range+0x18c/0x224 fs/file.c:818) r5:00000004 r4:8648f200 [<805cb7b4>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xed801fa8 to 0xed801ff0) 1fa0: 00000000 00000000 00000003 0000001e 00000000 7eb1c918 1fc0: 00000000 00000000 00000000 000001b4 0078ce9d ffffffff 00000000 003562e4 1fe0: 7eb1c840 7eb1c830 0002853c 00130820 r10:000001b4 r9:84856200 r8:8020029c r7:000001b4 r6:00000000 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) r7:60000093 r6:60000093 r5:82332444 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 r6:00000013 r5:00000000 r4:00000001 [<8021e594>] (dump_stack) from [<81b425fc>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b424ac>] (nmi_cpu_backtrace) from [<81b42750>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83380000 r5:82a1c7b8 r4:ffffffff [<81b4261c>] (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 r5:00007ef1 r4:00000048 [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4a28c>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4a28c>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4a28c>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b4a224>] (sys_info) from [<8038f854>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b4a224>] (sys_info) from [<8038f854>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007ef1 r4:0000000a [<8038f4b4>] (watchdog) from [<80281700>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:83110880 r7:00000000 r6:8038f4b4 r5:83380000 r4:8387c640 [<802815e4>] (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 r5:802815e4 r4:8387c640 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3103 Comm: sshd-session Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at should_failslab+0x0/0x94 mm/failslab.c:20 LR is at slab_pre_alloc_hook mm/slub.c:4567 [inline] LR is at slab_alloc_node mm/slub.c:4925 [inline] LR is at kmem_cache_alloc_noprof+0x5c/0x3e0 mm/slub.c:4959 pc : [<805675b0>] lr : [<80545038>] psr: 600f0013 sp : df9918e8 ip : df991940 fp : df99193c r10: 8467811c r9 : 85253080 r8 : 00000000 r7 : 84100000 r6 : 81635d10 r5 : 00000820 r4 : 830e5c00 r3 : 000000c0 r2 : 00000000 r1 : 00000820 r0 : 830e5c00 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 858ff340 DAC: 00000000 Call trace: [<80544fdc>] (kmem_cache_alloc_noprof) from [<81635d10>] (skb_clone+0x60/0x1c8 net/core/skbuff.c:2110) r10:8467811c r9:85253080 r8:00000000 r7:8467811c r6:82c0f54d r5:85253080 r4:00000820 [<81635cb0>] (skb_clone) from [<8164d930>] (dev_queue_xmit_nit+0xc4/0x2ac net/core/dev.c:2575) r7:8467811c r6:82c0f54d r5:8336fc40 r4:00000000 [<8164d86c>] (dev_queue_xmit_nit) from [<81658bc4>] (xmit_one net/core/dev.c:3885 [inline]) [<8164d86c>] (dev_queue_xmit_nit) from [<81658bc4>] (dev_hard_start_xmit+0xc4/0x324 net/core/dev.c:3905) r10:828d54ce r9:82a0b150 r8:00000000 r7:00000000 r6:00000000 r5:84678000 r4:85253080 [<81658b00>] (dev_hard_start_xmit) from [<816e05b4>] (sch_direct_xmit+0xa0/0x44c net/sched/sch_generic.c:372) r10:5b511000 r9:00000001 r8:00000000 r7:84678000 r6:83138a00 r5:85253080 r4:846e7800 [<816e0514>] (sch_direct_xmit) from [<81659a7c>] (__dev_xmit_skb net/core/dev.c:4211 [inline]) [<816e0514>] (sch_direct_xmit) from [<81659a7c>] (__dev_queue_xmit+0xb14/0x128c net/core/dev.c:4833) r9:a42e5b00 r8:ff7f6b00 r7:84678000 r6:846e7800 r5:83138a00 r4:85253080 [<81658f68>] (__dev_queue_xmit) from [<818266ac>] (dev_queue_xmit include/linux/netdevice.h:3446 [inline]) [<81658f68>] (__dev_queue_xmit) from [<818266ac>] (neigh_hh_output include/net/neighbour.h:544 [inline]) [<81658f68>] (__dev_queue_xmit) from [<818266ac>] (neigh_output include/net/neighbour.h:558 [inline]) [<81658f68>] (__dev_queue_xmit) from [<818266ac>] (ip_finish_output2+0x36c/0x790 net/ipv4/ip_output.c:236) r10:82e38300 r9:00000000 r8:00000010 r7:00000000 r6:0000000e r5:85253080 r4:848a8500 [<81826340>] (ip_finish_output2) from [<818279d8>] (__ip_finish_output.part.0+0x9c/0x150 net/ipv4/ip_output.c:314) r8:84678000 r7:82e38300 r6:000005dc r5:8590b640 r4:85253080 [<8182793c>] (__ip_finish_output.part.0) from [<81827ac8>] (__ip_finish_output+0x3c/0x40 net/ipv4/ip_output.c:304) r9:00000000 r8:84678000 r7:00000001 r6:8590b640 r5:82e38300 r4:85253080 [<81827a8c>] (__ip_finish_output) from [<81827b34>] (ip_finish_output net/ipv4/ip_output.c:324 [inline]) [<81827a8c>] (__ip_finish_output) from [<81827b34>] (NF_HOOK_COND include/linux/netfilter.h:307 [inline]) [<81827a8c>] (__ip_finish_output) from [<81827b34>] (ip_output+0x68/0x104 net/ipv4/ip_output.c:437) [<81827acc>] (ip_output) from [<81829328>] (dst_output include/net/dst.h:470 [inline]) [<81827acc>] (ip_output) from [<81829328>] (ip_local_out net/ipv4/ip_output.c:131 [inline]) [<81827acc>] (ip_output) from [<81829328>] (__ip_queue_xmit+0x190/0x528 net/ipv4/ip_output.c:533) r8:8590b8f8 r7:85444f80 r6:00000001 r5:8590b640 r4:85253080 [<81829198>] (__ip_queue_xmit) from [<818296d4>] (ip_queue_xmit+0x14/0x18 net/ipv4/ip_output.c:547) r10:0202000a r9:3b57bc20 r8:0000079e r7:00000014 r6:00000003 r5:8590b640 r4:85253080 [<818296c0>] (ip_queue_xmit) from [<818511c4>] (__tcp_transmit_skb+0x658/0x10a4 net/ipv4/tcp_output.c:1716) [<81850b6c>] (__tcp_transmit_skb) from [<8185316c>] (tcp_transmit_skb net/ipv4/tcp_output.c:1734 [inline]) [<81850b6c>] (__tcp_transmit_skb) from [<8185316c>] (tcp_write_xmit+0x4dc/0x19e4 net/ipv4/tcp_output.c:3062) r10:a215d86f r9:8590b76c r8:000000a4 r7:000005b4 r6:000005b4 r5:8590b640 r4:85252fc0 [<81852c90>] (tcp_write_xmit) from [<818546ac>] (__tcp_push_pending_frames+0x38/0x11c net/ipv4/tcp_output.c:3245) r10:00000040 r9:8590b640 r8:00000000 r7:000005b4 r6:00000001 r5:85252fc0 r4:8590b640 [<81854674>] (__tcp_push_pending_frames) from [<8183797c>] (tcp_push+0xcc/0x144 net/ipv4/tcp.c:772) r7:000005b4 r6:00000001 r5:85252fc0 r4:8590b640 [<818378b0>] (tcp_push) from [<8183adb8>] (tcp_sendmsg_locked+0x480/0x10f8 net/ipv4/tcp.c:1414) r9:8590b640 r8:000000a4 r7:df991e70 r6:00000000 r5:85252fc0 r4:85252fc0 [<8183a938>] (tcp_sendmsg_locked) from [<8183ba60>] (tcp_sendmsg+0x30/0x48 net/ipv4/tcp.c:1451) r10:81e609c0 r9:84100000 r8:81620bf4 r7:83e73800 r6:000000a4 r5:df991e70 r4:8590b640 [<8183ba30>] (tcp_sendmsg) from [<81882a8c>] (inet_sendmsg+0x40/0x4c net/ipv4/af_inet.c:865) r7:83e73800 r6:8590b640 r5:000000a4 r4:df991e70 [<81882a4c>] (inet_sendmsg) from [<81620bc0>] (sock_sendmsg_nosec net/socket.c:775 [inline]) [<81882a4c>] (inet_sendmsg) from [<81620bc0>] (__sock_sendmsg+0x44/0x78 net/socket.c:790) r7:83e73800 r6:84dcbbc0 r5:df991e70 r4:00000000 [<81620b7c>] (__sock_sendmsg) from [<81620ca4>] (sock_write_iter+0xb0/0xfc net/socket.c:1241) r7:83e73800 r6:84dcbbc0 r5:df991f08 r4:df991ef0 [<81620bf4>] (sock_write_iter) from [<8059f754>] (new_sync_write fs/read_write.c:595 [inline]) [<81620bf4>] (sock_write_iter) from [<8059f754>] (vfs_write fs/read_write.c:687 [inline]) [<81620bf4>] (sock_write_iter) from [<8059f754>] (vfs_write+0x3b8/0x42c fs/read_write.c:667) r7:00000000 r6:011fd568 r5:83e73800 r4:000000a4 [<8059f39c>] (vfs_write) from [<8059f994>] (ksys_write+0xcc/0xec fs/read_write.c:739) r10:00000004 r9:84100000 r8:8020029c r7:000000a4 r6:011fd568 r5:83e73800 r4:83e73800 [<8059f8c8>] (ksys_write) from [<8059f9c4>] (__do_sys_write fs/read_write.c:750 [inline]) [<8059f8c8>] (ksys_write) from [<8059f9c4>] (sys_write+0x10/0x14 fs/read_write.c:747) r7:00000004 r6:00000004 r5:00000000 r4:00000000 [<8059f9b4>] (sys_write) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf991fa8 to 0xdf991ff0) 1fa0: 00000000 00000000 00000004 011fd568 000000a4 00000000 1fc0: 00000000 00000000 00000004 00000004 000020b8 00000001 00000001 7ec482bc 1fe0: 00000001 7ec48178 00000000 769c6590