INFO: task syz.3.4975:26646 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4975 state:D stack:25720 pid:26646 tgid:26645 ppid:19397 task_flags:0x480140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 blk_mq_freeze_queue_wait+0x101/0x180 block/blk-mq.c:191 blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline] queue_limits_commit_update_frozen+0x55/0xd0 block/blk-settings.c:590 nbd_set_size+0x4c5/0x7d0 drivers/block/nbd.c:383 nbd_genl_size_set drivers/block/nbd.c:2111 [inline] nbd_genl_reconfigure+0x7e1/0x1040 drivers/block/nbd.c:2444 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2712 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2766 __sys_sendmsg net/socket.c:2798 [inline] __do_sys_sendmsg net/socket.c:2803 [inline] __se_sys_sendmsg net/socket.c:2801 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2801 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4c7df9e159 RSP: 002b:00007f4c7ef31028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4c7e225fa0 RCX: 00007f4c7df9e159 RDX: 0000000000004800 RSI: 0000200000000340 RDI: 0000000000000004 RBP: 00007f4c7e03506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4c7e226038 R14: 00007f4c7e225fa0 R15: 00007ffe749e58d8 INFO: task syz.1.4978:26657 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.4978 state:D stack:25664 pid:26657 tgid:26656 ppid:16575 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f473555e98e RSP: 002b:00007f47337f4e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f47337f66c0 RCX: 00007f473555e98e RDX: 0000000000000020 RSI: 00007f47337f5000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007f47337f4f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f47337f4f58 R14: 00007f47337f5000 R15: 0000000000000000 INFO: task syz.1.4978:26660 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.4978 state:D stack:27256 pid:26660 tgid:26656 ppid:16575 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f473555e98e RSP: 002b:00007f47337d3e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f47337d56c0 RCX: 00007f473555e98e RDX: 0000000000000020 RSI: 00007f47337d4000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f47337d3f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 00007f47337d3f58 R14: 00007f47337d4000 R15: 0000000000000000 INFO: task syz.1.4978:26663 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.4978 state:D stack:27232 pid:26663 tgid:26656 ppid:16575 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f473555e98e RSP: 002b:00007f47337b2e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f47337b46c0 RCX: 00007f473555e98e RDX: 000000000000001c RSI: 00007f47337b3000 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00007f47337b2f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 00007f47337b2f58 R14: 00007f47337b3000 R15: 0000000000000000 INFO: task syz.1.4978:26665 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.4978 state:D stack:27232 pid:26665 tgid:26656 ppid:16575 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f473555e98e RSP: 002b:00007f473338fe88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f47333916c0 RCX: 00007f473555e98e RDX: 0000000000000020 RSI: 00007f4733390000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007f473338ff04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f473338ff58 R14: 00007f4733390000 R15: 0000000000000000 INFO: task syz.4.4981:26671 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.4981 state:D stack:23720 pid:26671 tgid:26669 ppid:17780 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6c6875e98e RSP: 002b:00007f6c69743e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f6c697456c0 RCX: 00007f6c6875e98e RDX: 0000000000000020 RSI: 00007f6c69744000 RDI: 000000000000000b RBP: 0000000000000000 R08: 00007f6c69743f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000b R13: 00007f6c69743f58 R14: 00007f6c69744000 R15: 0000000000000000 INFO: task syz.2.4982:26674 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.4982 state:D stack:27904 pid:26674 tgid:26672 ppid:18939 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f010a55e98e RSP: 002b:00007f010b4c7e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f010b4c96c0 RCX: 00007f010a55e98e RDX: 0000000000000020 RSI: 00007f010b4c8000 RDI: 000000000000000b RBP: 0000000000000000 R08: 00007f010b4c7f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000b R13: 00007f010b4c7f58 R14: 00007f010b4c8000 R15: 0000000000000000 INFO: task syz.2.4982:26680 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.4982 state:D stack:27904 pid:26680 tgid:26672 ppid:18939 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f010a55e98e RSP: 002b:00007f010b464e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f010b4666c0 RCX: 00007f010a55e98e RDX: 0000000000000020 RSI: 00007f010b465000 RDI: 0000000000000007 RBP: 0000000000000000 R08: 00007f010b464f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000007 R13: 00007f010b464f58 R14: 00007f010b465000 R15: 0000000000000000 INFO: task syz.0.4983:26685 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.4983 state:D stack:26448 pid:26685 tgid:26684 ppid:18119 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7376 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 genl_lock net/netlink/genetlink.c:35 [inline] genl_op_lock net/netlink/genetlink.c:60 [inline] genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7febfeb5e98e RSP: 002b:00007febfcdf4e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007febfcdf66c0 RCX: 00007febfeb5e98e RDX: 0000000000000024 RSI: 00007febfcdf5000 RDI: 000000000000000c RBP: 0000000000000000 R08: 00007febfcdf4f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c R13: 00007febfcdf4f58 R14: 00007febfcdf5000 R15: 0000000000000000 Showing all locks held in the system: locks held by kworker/u8:0/12: 2, last CPU#0: #0: ffff88802a1b3140 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88802a1b3140 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88802a1b3140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88802a1b3140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 locks held by pr/ttyS0/16: 2, last CPU#0: #0: ffffffff8ec36538 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #0: ffffffff8ec36538 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline] #0: ffffffff8ec36538 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291 #1: ffffffff9ad452d8 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline] #1: ffffffff9ad452d8 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413 locks held by khungtaskd/31: 1, last CPU#1: #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by getty/5369: 2, on CPU#1: #0: ffff88803345d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor/5601: 2, last CPU#1: #0: ffff888034565038 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline] #0: ffff888034565038 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299 #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290 locks held by udevd/7116: 1, on CPU#0: #0: ffff8880276c6350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990 locks held by kworker/u8:13/13659: 5, last CPU#1: #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90004777c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90004777c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90004777c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90004777c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff8ebe9970 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_disable+0x12/0x20 kernel/jump_label.c:247 #3: ffffffff8ee38ca0 (jump_label_mutex){+.+.}-{4:4}, at: jump_label_lock kernel/jump_label.c:27 [inline] #3: ffffffff8ee38ca0 (jump_label_mutex){+.+.}-{4:4}, at: static_key_disable_cpuslocked+0x8d/0x1a0 kernel/jump_label.c:238 #4: ffffffff8ebff720 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145 locks held by syz.3.4975/26646: 6, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 #2: ffff8880276caa60 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x4a6/0x1040 drivers/block/nbd.c:2435 #3: ffff88802775c7c8 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1101 [inline] #3: ffff88802775c7c8 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x284/0x7d0 drivers/block/nbd.c:375 #4: ffff88802775c190 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline] #4: ffff88802775c190 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0 block/blk-settings.c:590 #5: ffff88802775c1c8 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline] #5: ffff88802775c1c8 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0 block/blk-settings.c:590 locks held by syz.1.4978/26657: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.1.4978/26660: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.1.4978/26663: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.1.4978/26665: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.4.4981/26671: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.2.4982/26674: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.2.4982/26680: 2, on CPU#1: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz.0.4983/26685: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26721: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26723: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26741: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26745: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26770: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26818: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26821: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26846: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26850: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26853: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26914: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26918: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26941: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26943: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 locks held by syz-executor/26948: 2, on CPU#0: #0: ffffffff902c61c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff902c6000 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:416 Code: 99 54 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 2c 9e c4 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 17 d7 76 06 cc 44 89 f9 80 e1 07 38 c1 RSP: 0018:ffffc90000157900 EFLAGS: 00000002 RAX: 0000000000000078 RBX: 0000000000000078 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020 RBP: 00000000000003f8 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff857341c0 R12: dffffc0000000000 R13: 0000000000000078 R14: ffffffff9ad45300 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124cc6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa30ae59710 CR3: 000000000eb48000 CR4: 00000000003526f0 Call Trace: serial_port_out include/linux/serial_core.h:817 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3287 [inline] __serial8250_console_fifo_write+0x1e6/0x3e0 drivers/tty/serial/8250/8250_port.c:3359 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline] serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline] nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245