[] entry_SYSCALL_64_fastpath+0x1e/0x9a INFO: task syz-executor2:11502 blocked for more than 140 seconds. Not tainted 4.4.157+ #101 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D ffff8800b3ec7dc8 29728 11502 2100 0x00000004 ffff8800b3ec7dc8 0000000000000000 ffff8801bcb53848 ffffed003796a708 ffff8801bcb52f00 ffff8801db71f180 ffff8801db71f1a8 ffff8801db71e898 ffff8801db71e880 ffff8800b8b6af80 ffff8801bcb52f80 0000000000000000 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3355 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3388 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x307/0x840 kernel/locking/mutex.c:621 [] __fdget_pos+0xac/0xd0 fs/file.c:780 [] fdget_pos fs/read_write.c:266 [inline] [] SYSC_lseek fs/read_write.c:279 [inline] [] SyS_lseek+0x22/0x180 fs/read_write.c:276 [] entry_SYSCALL_64_fastpath+0x1e/0x9a 1 lock held by syz-executor2/11502: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0xac/0xd0 fs/file.c:780 Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 8756 Comm: syz-executor0 Not tainted 4.4.157+ #101 task: ffff8801c1090000 task.stack: ffff8801c0600000 RIP: 0010:[] [] syscall_trace_enter_phase1+0x2c3/0x480 arch/x86/entry/common.c:134 RSP: 0018:ffff8801c0607e60 EFLAGS: 00000293 RAX: ffff8801c1090000 RBX: 1ffff100380c0fd0 RCX: 1ffff100380c0ff3 RDX: 0000000000000000 RSI: ffffffff81004a8e RDI: ffff8801c0607ea0 RBP: ffff8801c0607f48 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffff8801c0607f20 R13: 0000000000000100 R14: 00000000c000003e R15: ffff8801c0607f58 FS: 00007f4f41c8c700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5c9134b3c0 CR3: 00000000b37a8000 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff8801c0607fd0 0000000000000080 000000000072bfa8 0000000000000000 0000000041b58ab3 ffffffff82c38a40 ffffffff810047d0 ffffed00380c0001 c000003e000000ca 0000000000457679 000000000072bfa8 0000000000000080 Call Trace: [] tracesys+0xd/0x44 Code: 89 44 24 b0 48 b8 00 00 00 00 00 fc ff df 80 3c 01 00 0f 85 92 01 00 00 49 8b 47 20 49 89 44 24 b8 e8 f2 02 2f 00 49 8d 7c 24 80 58 47 2f 00 41 89 c4 49 83 fc 01 74 1f e8 da 02 2f 00 4d 85 NMI backtrace for cpu 1 CPU: 1 PID: 20 Comm: khungtaskd Not tainted 4.4.157+ #101 task: ffff8801da6f4740 task.stack: ffff8800001c8000 RIP: 0010:[] [] native_apic_mem_write arch/x86/include/asm/apic.h:93 [inline] RIP: 0010:[] [] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline] RIP: 0010:[] [] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline] RIP: 0010:[] [] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69 RSP: 0018:ffff8800001cfcc8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300 RBP: ffff8800001cfcf0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246 R13: 0000000003000000 R14: ffffffff82e5f3a0 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000619570 CR3: 00000001d74e4000 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff82e5f3a0 ffffffff831a3020 0000000000000007 fffffbfff06344e4 0000000000000008 ffff8800001cfd10 ffffffff81091a11 ffffffff82920920 0000000000000003 ffff8800001cfd68 ffffffff81a604a2 ffffffff813919a5 Call Trace: [] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33 [] nmi_trigger_all_cpu_backtrace.cold.0+0x70/0xae lib/nmi_backtrace.c:85 [] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 [] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog.cold.0+0xd3/0xee kernel/hung_task.c:238 [] kthread+0x268/0x300 kernel/kthread.c:211 [] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510 Code: 00 c3 5f ff 80 e6 10 75 e1 41 c1 e5 18 44 89 2c 25 10 c3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 c3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f2