INFO: task syz-executor.2:1498 blocked for more than 140 seconds. Not tainted 4.14.198-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28912 1498 6363 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1731 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 ucma_close+0xfc/0x340 drivers/infiniband/core/ucma.c:1749 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 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+0x46/0xbb RIP: 0033:0x417781 RSP: 002b:00007ffdf06b1930 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000417781 RDX: 0000000000000000 RSI: 000000000000086e RDI: 0000000000000004 RBP: 0000000000000001 R08: 00000000216a486e R09: 00000000216a4872 R10: 00007ffdf06b1a10 R11: 0000000000000293 R12: ffffffffffffffff R13: 00000000001eae5f R14: 00000000000003e8 R15: 000000000118bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1053: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/6024: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1053 Comm: khungtaskd Not tainted 4.14.198-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+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f 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+0x5b9/0xb40 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: 3652 Comm: systemd-journal Not tainted 4.14.198-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888094382340 task.stack: ffff888094388000 RIP: 0010:get_page_from_freelist+0xe75/0x2560 mm/page_alloc.c:3172 RSP: 0018:ffff88809438fa18 EFLAGS: 00000046 RAX: ffff88809438fc30 RBX: ffff88812fffe5d0 RCX: 1ffff11025fff6de RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff88812fffb888 RBP: ffff88812fffbcc0 R08: 0000000000000000 R09: 000000000005ea6b R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000002c47 R13: dffffc0000000000 R14: ffff88812fffbd80 R15: ffff88812fffb6c0 FS: 00007ffa5b5ee8c0(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffa57bce000 CR3: 0000000094139000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __alloc_pages_nodemask+0x365/0x2720 mm/page_alloc.c:4184 __alloc_pages include/linux/gfp.h:484 [inline] __alloc_pages_node include/linux/gfp.h:497 [inline] kmem_getpages mm/slab.c:1419 [inline] cache_grow_begin+0x8f/0x420 mm/slab.c:2676 cache_alloc_refill+0x273/0x350 mm/slab.c:3043 ____cache_alloc mm/slab.c:3125 [inline] __do_cache_alloc mm/slab.c:3347 [inline] slab_alloc mm/slab.c:3382 [inline] kmem_cache_alloc+0x333/0x3c0 mm/slab.c:3550 getname_flags+0xc8/0x550 fs/namei.c:138 user_path_at_empty+0x2a/0x50 fs/namei.c:2631 user_path_at include/linux/namei.h:57 [inline] SYSC_faccessat fs/open.c:403 [inline] SyS_faccessat+0x21b/0x680 fs/open.c:353 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7ffa5a8aa9c7 RSP: 002b:00007fff4ac41598 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007fff4ac445c0 RCX: 00007ffa5a8aa9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055893c1129a3 RBP: 00007fff4ac416e0 R08: 000055893c1083e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055893c5d48c0 R15: 00007fff4ac41bd0 Code: ff ff 48 89 df e8 2c 3e 14 00 e9 59 f4 ff ff 48 8b 84 24 98 00 00 00 0f b6 00 84 c0 74 08 3c 03 0f 8e d1 12 00 00 48 8b 44 24 30 <8b> 40 18 89 44 24 24 48 8b 44 24 60 48 c1 e8 03 42 80 3c 28 00