NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.2:18316 blocked for more than 140 seconds. Not tainted 4.14.177-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28688 18316 6350 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1497 __fput+0x25f/0x790 fs/file_table.c:210 task_work_run+0x113/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1d6/0x220 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x416421 RSP: 002b:00007ffc73bb9d10 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000416421 RDX: 0000000000000000 RSI: 0000000000000ed7 RDI: 0000000000000005 RBP: 0000000000000001 R08: 00000000f5f1eedb R09: 0000000000000000 R10: 00007ffc73bb9e00 R11: 0000000000000293 R12: 0000000000790248 R13: 00000000000428aa R14: ffffffffffffffff R15: 000000000078bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1057: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/6014: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 1 lock held by syz-executor.2/18316: #0: (&fb_info->lock){+.+.}, at: [] fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1497 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1057 Comm: khungtaskd Not tainted 4.14.177-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e2/0xb80 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted 4.14.177-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a98521c0 task.stack: ffff8880a9858000 RIP: 0010:find_rr_leaf net/ipv6/route.c:716 [inline] RIP: 0010:rt6_select net/ipv6/route.c:753 [inline] RIP: 0010:ip6_pol_route+0x283/0x1e30 net/ipv6/route.c:1120 RSP: 0018:ffff8880a985f718 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff8880920221c0 RCX: ffff8880a985f7d8 RDX: 0000000000000100 RSI: 0000000000000031 RDI: ffff888092022328 RBP: 0000000000000100 R08: 0000000000000000 R09: ffff8880a985f7c8 R10: ffff8880a9852a70 R11: ffff8880a98521c0 R12: ffff88809b48b380 R13: ffff888096848b00 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000c70100 CR3: 0000000089aff000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fib6_rule_lookup+0xc3/0x3e0 net/ipv6/fib6_rules.c:83 ip6_route_input+0x4c9/0x850 net/ipv6/route.c:1293 ip6_rcv_finish+0x1dc/0x790 net/ipv6/ip6_input.c:69 NF_HOOK include/linux/netfilter.h:250 [inline] NF_HOOK include/linux/netfilter.h:244 [inline] ipv6_rcv+0xe5c/0x1c30 net/ipv6/ip6_input.c:218 __netif_receive_skb_core+0x1e50/0x2c00 net/core/dev.c:4478 __netif_receive_skb+0x27/0x1a0 net/core/dev.c:4516 process_backlog+0x214/0x750 net/core/dev.c:5198 napi_poll net/core/dev.c:5599 [inline] net_rx_action+0x456/0xe90 net/core/dev.c:5665 __do_softirq+0x254/0x9bf kernel/softirq.c:288 run_ksoftirqd kernel/softirq.c:670 [inline] run_ksoftirqd+0x87/0x1a0 kernel/softirq.c:662 smpboot_thread_fn+0x5c1/0x920 kernel/smpboot.c:164 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 0f 85 b4 12 00 00 48 8b 9b 98 00 00 00 48 85 db 74 39 e8 20 8a e6 fb 48 8d bb 68 01 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 <84> c0 74 08 3c 03 0f 8e 8e 12 00 00 8b ab 68 01 00 00 e8 f6 89