TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. sock: process `syz-executor1' is using obsolete setsockopt SO_BSDCOMPAT TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. INFO: task syz-executor6:3878 blocked for more than 140 seconds. Not tainted 4.4.140-ged9bdc8 #68 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D ffff8801bd59fa68 28208 3878 1 0x00000004 ffff8801bd59fa68 0000000000000000 ffff8801d88988e0 ffffed003b11311b ffff8801d8898000 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8 ffff8801db31f4c0 ffff8801d92c6000 ffff8801d8898000 0000000000000000 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3359 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3392 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x307/0x850 kernel/locking/mutex.c:621 [] lo_ioctl+0x8b/0x1ad0 drivers/block/loop.c:1355 [] __blkdev_driver_ioctl block/ioctl.c:288 [inline] [] blkdev_ioctl+0x7b8/0x19c0 block/ioctl.c:584 [] block_ioctl+0xde/0x120 fs/block_dev.c:1625 [] vfs_ioctl fs/ioctl.c:43 [inline] [] file_ioctl fs/ioctl.c:470 [inline] [] do_vfs_ioctl+0x63f/0xf40 fs/ioctl.c:605 [] SYSC_ioctl fs/ioctl.c:622 [inline] [] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613 [] entry_SYSCALL_64_fastpath+0x22/0x9e 1 lock held by syz-executor6/3878: #0: (&lo->lo_ctl_mutex/1){+.+.+.}, at: [] lo_ioctl+0x8b/0x1ad0 drivers/block/loop.c:1355 Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 491 Comm: khungtaskd Not tainted 4.4.140-ged9bdc8 #68 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d8e3c800 task.stack: ffff8801d8db0000 RIP: 0010:[] [] native_apic_mem_write arch/x86/include/asm/apic.h:94 [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:ffff8801d8db7cc8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8801d8db7cf0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246 R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f6e0 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fda24f01df8 CR3: 00000000aeabd000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8446f6e0 ffffffff84a19060 0000000000000007 fffffbfff0942cbc 0000000000000040 ffff8801d8db7d10 ffffffff810b5f51 ffffffff83c0b760 0000000000000003 ffff8801d8db7d68 ffffffff81e19103 ffffffff8140ddaf Call Trace: [] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33 [] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad 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.1+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: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 d2 NMI backtrace for cpu 1 CPU: 1 PID: 19750 Comm: syz-executor3 Not tainted 4.4.140-ged9bdc8 #68 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801b7c48000 task.stack: ffff8801bd8d8000 RIP: 0010:[] [] is_loop_device drivers/block/loop.c:713 [inline] RIP: 0010:[] [] loop_set_fd drivers/block/loop.c:897 [inline] RIP: 0010:[] [] lo_ioctl+0x1558/0x1ad0 drivers/block/loop.c:1358 RSP: 0018:ffff8801bd8dfb98 EFLAGS: 00000a06 RAX: 1ffff1003b382b39 RBX: ffff8801d9c159c8 RCX: dffffc0000000000 RDX: 0000000000040000 RSI: ffffffff8251c515 RDI: ffff8800b63a4bb0 RBP: ffff8801bd8dfc18 R08: ffff8801b7c48928 R09: 0000000000000001 R10: 0000000000000000 R11: ffff8801b7c48000 R12: ffff8801d9c157e0 R13: ffff8801d9c11140 R14: ffff8801d6b71200 R15: ffff8801d6b71358 FS: 00007fce955c9700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd2dc78c140 CR3: 00000000b6aad000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000b0000004c 0000000100000000 0000000000000000 ffff8801d6b71350 0000000000006000 0000000041b58ab3 ffff8801d9c159c8 ffff8800b0dbfe00 ffff8801d9c11230 000000000002001d 0000000000000000 ffff8801d9c11140 Call Trace: [] __blkdev_driver_ioctl block/ioctl.c:288 [inline] [] blkdev_ioctl+0x7b8/0x19c0 block/ioctl.c:584 [] block_ioctl+0xde/0x120 fs/block_dev.c:1625 [] vfs_ioctl fs/ioctl.c:43 [inline] [] file_ioctl fs/ioctl.c:470 [inline] [] do_vfs_ioctl+0x63f/0xf40 fs/ioctl.c:605 [] SYSC_ioctl fs/ioctl.c:622 [inline] [] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613 [] entry_SYSCALL_64_fastpath+0x22/0x9e Code: 00 00 48 89 f8 48 c1 e8 03 80 3c 08 00 0f 85 cd 03 00 00 48 8b 9b b0 01 00 00 48 b9 00 00 00 00 00 fc ff df 48 89 d8 48 c1 e8 03 <80> 3c 08 00 0f 85 9e 03 00 00 48 8b 1b 48 85 db 0f 84 8f fd ff