TCP: request_sock_TCPv6: Possible SYN flooding on port 20000. Sending cookies. Check SNMP counters. INFO: task syz-executor.0:12471 blocked for more than 140 seconds. Not tainted 4.19.81 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28216 12471 7642 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1782 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 kthread_stop+0x116/0x6c0 kernel/kthread.c:550 vivid_stop_generating_vid_cap+0x1e0/0x6e2 drivers/media/platform/vivid/vivid-kthread-cap.c:922 vid_cap_stop_streaming+0x8a/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:256 __vb2_queue_cancel+0xb1/0x790 drivers/media/common/videobuf2/videobuf2-core.c:1682 vb2_core_streamoff+0x60/0x150 drivers/media/common/videobuf2/videobuf2-core.c:1816 __vb2_cleanup_fileio+0x78/0x170 drivers/media/common/videobuf2/videobuf2-core.c:2343 vb2_core_queue_release+0x20/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2070 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:671 [inline] _vb2_fop_release+0x1cf/0x2a0 drivers/media/common/videobuf2/videobuf2-v4l2.c:842 vb2_fop_release+0x75/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:856 vivid_fop_release+0x18e/0x430 drivers/media/platform/vivid/vivid-core.c:474 v4l2_release+0xf9/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x2dd/0x8b0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413ae1 Code: e0 48 83 f9 40 4d 19 ed 4d 21 e8 4d 09 c3 4d 8d 04 09 48 83 fb 01 74 c6 eb 1f 4d 89 da 49 83 e3 0f 49 81 cb f0 00 00 00 44 88 <1a> 49 c1 ea 04 49 83 c0 fc 48 ff ca 4d 89 d3 49 83 f8 04 73 db eb RSP: 002b:00007ffd1b8fb7b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000413ae1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffff8100a1f1 R09: 00000000f1b0d8da R10: 00007ffd1b8fb890 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000760a00 R15: 000000000075bf2c Showing all locks held in the system: 2 locks held by kworker/u4:0/7: #0: 000000000958cb83 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9656 [inline] #0: 000000000958cb83 (&rq->lock){-.-.}, at: pick_next_task_fair+0xfae/0x1580 kernel/sched/fair.c:6837 #1: 000000007e548d1a (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6054 1 lock held by khungtaskd/1037: #0: 000000007e548d1a (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 2 locks held by rsyslogd/7479: #0: 000000008fdf31cb (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 #1: 0000000071ff217e (fs_reclaim){+.+.}, at: syslog_print kernel/printk/printk.c:1310 [inline] #1: 0000000071ff217e (fs_reclaim){+.+.}, at: do_syslog kernel/printk/printk.c:1470 [inline] #1: 0000000071ff217e (fs_reclaim){+.+.}, at: do_syslog+0xa6d/0x1690 kernel/printk/printk.c:1444 2 locks held by getty/7600: #0: 00000000d80a0752 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000005058922d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7601: #0: 0000000014363219 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000002a43c2c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7602: #0: 000000009df89e0b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000e479bcef (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7603: #0: 00000000402fbcba (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000177f6ec1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7604: #0: 0000000054c24b1f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000ce429678 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7605: #0: 000000003b1af53b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000008c7e4c5b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7606: #0: 000000007d369ba1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000003af47a58 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1037 Comm: khungtaskd Not tainted 4.19.81 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 4.19.81 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_memory_region+0x1f/0x190 mm/kasan/kasan.c:266 Code: 90 66 2e 0f 1f 84 00 00 00 00 00 48 85 f6 0f 84 21 01 00 00 48 b8 ff ff ff ff ff 7f ff ff 55 0f b6 d2 48 39 c7 48 89 e5 41 55 <41> 54 53 0f 86 f6 00 00 00 4c 8d 5c 37 ff 49 89 f8 48 b8 00 00 00 RSP: 0018:ffff8880aa21fbe0 EFLAGS: 00000212 RAX: ffff7fffffffffff RBX: ffff8880988ecb88 RCX: ffffffff8152c6d8 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880988ecb88 RBP: ffff8880aa21fbe8 R08: 00000000000042fc R09: 0000000000000002 R10: ffff8880aa206a90 R11: ffffffff89e6eca0 R12: ffff8880988ecb88 R13: ffff8880988ecb90 R14: ffff8880988ecb98 R15: 0000000000000027 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd8ff2a7000 CR3: 00000000a5605000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278 atomic_cmpxchg include/asm-generic/atomic-instrumented.h:57 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0xc8/0x240 kernel/locking/spinlock_debug.c:113 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline] _raw_spin_lock_bh+0x3b/0x50 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] batadv_nc_purge_paths+0xd8/0x370 net/batman-adv/network-coding.c:453 batadv_nc_worker+0x2cf/0x760 net/batman-adv/network-coding.c:733 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415