tty_warn_deprecated_flags: 'syz-executor.5' is using deprecated serial flags (with no effect): 00008500 INFO: task syz-executor.4:29021 blocked for more than 140 seconds. Not tainted 4.9.141+ #23 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29816 29021 29017 0x20020000 ffff8801a82917c0 ffff88016f7d6880 ffff88016f7d6880 ffff8801c70e97c0 ffff8801db621018 ffff880171547b50 ffffffff828075c2 0000000000000000 ffffffff83cd4080 ffff880100000000 0000000000003546 ffff8801db6218f0 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3553 [] schedule_timeout+0x735/0xe20 kernel/time/timer.c:1771 [] down_read_failed drivers/tty/tty_ldsem.c:241 [inline] [] __ldsem_down_read_nested+0x33c/0x610 drivers/tty/tty_ldsem.c:332 [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 [] tty_ldisc_ref_wait+0x25/0x80 drivers/tty/tty_ldisc.c:275 [] tty_compat_ioctl+0x12d/0x270 drivers/tty/tty_io.c:3039 [] C_SYSC_ioctl fs/compat_ioctl.c:1602 [inline] [] compat_SyS_ioctl+0x12d/0x1fd0 fs/compat_ioctl.c:1549 [] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline] [] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390 [] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137 Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x11c/0xa20 kernel/hung_task.c:239 #1: (tasklist_lock){.+.?..}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/1912: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0xac/0xd0 fs/file.c:781 2 locks held by getty/2039: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.4/21327: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.4/21917: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.4/22210: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.0/23470: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.0/23817: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor.4/23898: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 1 lock held by syz-executor.1/24000: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 2 locks held by syz-executor.4/25315: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor.0/26244: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 1 lock held by syz-executor.0/26305: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 1 lock held by syz-executor.0/26360: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 2 locks held by syz-executor.1/26720: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.2/26829: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.1/27846: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.2/27991: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.5/28876: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.4/29017: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor.4/29021: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 2 locks held by syz-executor.0/29124: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.4/29390: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.0/30286: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.4/31060: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.4/31233: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.2/31462: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.5/31534: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.1/31907: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.2/32448: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.1/609: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor.5/1250: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 2 locks held by syz-executor.4/1314: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor.5/1333: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 2 locks held by syz-executor.5/2353: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.3/2736: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor.2/3084: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 1 lock held by syz-executor.3/3138: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369 2 locks held by syz-executor.2/4290: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.2/4299: #0: (&tty->legacy_mutex){+.+.+.}, at: [] tty_lock+0x6a/0xd0 drivers/tty/tty_mutex.c:18 #1: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_write+0x32/0x37 drivers/tty/tty_ldsem.c:393 1 lock held by syz-executor.2/4312: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 2 locks held by syz-executor.5/4318: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor.5/4323: #0: (&tty->legacy_mutex){+.+.+.}, at: [] tty_lock+0x6a/0xd0 drivers/tty/tty_mutex.c:18 #1: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_write+0x32/0x37 drivers/tty/tty_ldsem.c:393 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #23 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810983b0 ffff8801d9907d40 ffffffff81b4df89 0000000000000000 0000000000000000 0000000000000003 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6ad/0xa20 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2067 Comm: sshd Not tainted 4.9.141+ #23 task: ffff8801d0a697c0 task.stack: ffff8801ce890000 RIP: 0010:[] c [] lock_is_held+0xa0/0x140 kernel/locking/lockdep.c:3793 RSP: 0018:ffff8801ce896f28 EFLAGS: 00000046 RAX: 0000000000000007 RBX: 0000000000000246 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff81ba7d7b RDI: ffff8801d0a6a06c RBP: ffff8801ce896f40 R08: ffff8801d0a6a158 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d0a697c0 R13: ffffffff830cc2e0 R14: ffff8801da568500 R15: 0000000000000246 FS: 00007f4f1f7ca7c0(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f57181ac518 CR3: 00000001d12fe000 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000000000003c ffffea00071f3b80c ffffffff822b8e08c ffff8801ce896f58c ffffffff81243e83c ffff8801c7cee8c0c ffff8801ce896f90c ffffffff814ef48fc ffff8801c7cee8c0c ffffffff827c56b8c ffff8801d667c400c 0000000000000001c Call Trace: [] rcu_read_lock_sched_held+0x103/0x120 kernel/rcu/update.c:112 [] trace_kmem_cache_free include/trace/events/kmem.h:143 [inline] [] kmem_cache_free+0x28f/0x310 mm/slub.c:2981 [] kfree_skbmem+0x98/0x100 net/core/skbuff.c:623 [] __kfree_skb net/core/skbuff.c:685 [inline] [] kfree_skb+0xd4/0x340 net/core/skbuff.c:705 [] packet_rcv_spkt+0xd8/0x4b0 net/packet/af_packet.c:1839 [] dev_queue_xmit_nit+0x5e1/0x820 net/core/dev.c:1950 [] xmit_one net/core/dev.c:2973 [inline] [] dev_hard_start_xmit+0xa6/0x8b0 net/core/dev.c:2993 [] sch_direct_xmit+0x2b3/0x580 net/sched/sch_generic.c:182 [] __dev_xmit_skb net/core/dev.c:3173 [inline] [] __dev_queue_xmit+0x152e/0x1b90 net/core/dev.c:3441 [] dev_queue_xmit+0x17/0x20 net/core/dev.c:3506 [] neigh_hh_output include/net/neighbour.h:468 [inline] [] dst_neigh_output include/net/dst.h:468 [inline] [] ip_finish_output2+0xc94/0x1100 net/ipv4/ip_output.c:225 [] ip_finish_output+0x3b5/0xc90 net/ipv4/ip_output.c:313 [] NF_HOOK_COND include/linux/netfilter.h:246 [inline] [] ip_output+0x1cd/0x550 net/ipv4/ip_output.c:401 [] dst_output include/net/dst.h:507 [inline] [] ip_local_out+0x9b/0x180 net/ipv4/ip_output.c:124 [] ip_queue_xmit+0x897/0x18c0 net/ipv4/ip_output.c:500 [] __tcp_transmit_skb+0x18bb/0x2df0 net/ipv4/tcp_output.c:1041 [] tcp_transmit_skb net/ipv4/tcp_output.c:1057 [inline] [] tcp_write_xmit+0xf7d/0x4580 net/ipv4/tcp_output.c:2221 [] __tcp_push_pending_frames+0xa4/0x250 net/ipv4/tcp_output.c:2402 [] tcp_push+0x3fe/0x5e0 net/ipv4/tcp.c:688 [] tcp_sendmsg+0x112b/0x2fd0 net/ipv4/tcp.c:1348 [] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770 [] sock_sendmsg_nosec net/socket.c:648 [inline] [] sock_sendmsg+0xbb/0x110 net/socket.c:658 [] sock_write_iter+0x223/0x3b0 net/socket.c:856 [] new_sync_write fs/read_write.c:496 [inline] [] __vfs_write+0x3d7/0x580 fs/read_write.c:509 [] vfs_write+0x187/0x520 fs/read_write.c:557 [] SYSC_write fs/read_write.c:604 [inline] [] SyS_write+0xd9/0x1c0 fs/read_write.c:596 [] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Code: c00 c48 cb8 c00 c00 c00 c00 c00 cfc cff cdf c48 c89 cfa c48 cc1 cea c03 c0f cb6 c14 c02 c48 c89 cf8 c83 ce0 c07 c83 cc0 c03 c38 cd0 c7c c08 c84 cd2 c0f c85 c8f c00 c00 c00 c<41> cc7 c84 c24 cac c08 c00 c00 c01 c00 c00 c00 c4c c89 cef ce8 c7c cfd cff cff c65 c