syzbot

INFO: task syz-executor.5:16485 can't die for more than 143 seconds.
task:syz-executor.5  state:D stack:27440 pid:16485 ppid:  8488 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4700 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5957
 schedule+0xd3/0x270 kernel/sched/core.c:6036
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6095
 __mutex_lock_common kernel/locking/mutex.c:1036 [inline]
 __mutex_lock+0xa46/0x1300 kernel/locking/mutex.c:1096
 refcount_dec_and_mutex_lock lib/refcount.c:118 [inline]
 refcount_dec_and_mutex_lock+0x50/0x140 lib/refcount.c:113
 nbd_put drivers/block/nbd.c:260 [inline]
 nbd_genl_connect+0xd69/0x1820 drivers/block/nbd.c:1999
 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:739
 genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
 genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:800
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:723
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2392
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2475
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
RSP: 002b:00007f33eea97188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038
R13: 00007ffe3e08e47f R14: 00007f33eea97300 R15: 0000000000022000
INFO: task syz-executor.5:16485 blocked for more than 143 seconds.
      Tainted: G        W         5.14.0-rc1-next-20210715-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:27440 pid:16485 ppid:  8488 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4700 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5957
 schedule+0xd3/0x270 kernel/sched/core.c:6036
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6095
 __mutex_lock_common kernel/locking/mutex.c:1036 [inline]
 __mutex_lock+0xa46/0x1300 kernel/locking/mutex.c:1096
 refcount_dec_and_mutex_lock lib/refcount.c:118 [inline]
 refcount_dec_and_mutex_lock+0x50/0x140 lib/refcount.c:113
 nbd_put drivers/block/nbd.c:260 [inline]
 nbd_genl_connect+0xd69/0x1820 drivers/block/nbd.c:1999
 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:739
 genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
 genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:800
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:723
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2392
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2475
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
RSP: 002b:00007f33eea97188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038
R13: 00007ffe3e08e47f R14: 00007f33eea97300 R15: 0000000000022000
INFO: task systemd-udevd:16498 blocked for more than 144 seconds.
      Tainted: G        W         5.14.0-rc1-next-20210715-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:systemd-udevd   state:D stack:28600 pid:16498 ppid:  4877 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4700 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5957
 schedule+0xd3/0x270 kernel/sched/core.c:6036
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6095
 __mutex_lock_common kernel/locking/mutex.c:1036 [inline]
 __mutex_lock+0xa46/0x1300 kernel/locking/mutex.c:1096
 del_gendisk+0x8b/0x770 block/genhd.c:587
 nbd_dev_remove drivers/block/nbd.c:241 [inline]
 nbd_put.part.0+0x82/0x160 drivers/block/nbd.c:263
 nbd_put drivers/block/nbd.c:1527 [inline]
 nbd_release+0x14d/0x1a0 drivers/block/nbd.c:1526
 blkdev_put_whole fs/block_dev.c:1277 [inline]
 blkdev_put+0x34f/0xae0 fs/block_dev.c:1574
 blkdev_close+0x8c/0xb0 fs/block_dev.c:1584
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f54530f9270
RSP: 002b:00007ffc39f43448 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f54530f9270
RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007f5453fb3710 R08: 000000000000004a R09: 0000000000000008
R10: 00005607c34a68a8 R11: 0000000000000246 R12: 0000000000000000
R13: 00005607c34ac6a0 R14: 0000000000000003 R15: 000000000000000e
INFO: task syz-executor.4:16509 can't die for more than 144 seconds.
task:syz-executor.4  state:D stack:28832 pid:16509 ppid:  8486 flags:0x00000004
Call Trace:
 context_switch kernel/sched/core.c:4700 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5957
 schedule+0xd3/0x270 kernel/sched/core.c:6036
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6095
 __mutex_lock_common kernel/locking/mutex.c:1036 [inline]
 __mutex_lock+0xa46/0x1300 kernel/locking/mutex.c:1096
 genl_lock net/netlink/genetlink.c:33 [inline]
 genl_rcv_msg+0x3e0/0x580 net/netlink/genetlink.c:798
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:723
 __sys_sendto+0x21c/0x320 net/socket.c:2019
 __do_sys_sendto net/socket.c:2031 [inline]
 __se_sys_sendto net/socket.c:2027 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2027
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x41956c
RSP: 002b:00007f0c6082c020 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f0c6082c110 RCX: 000000000041956c
RDX: 000000000000001c RSI: 00007f0c6082c160 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f0c6082c074 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f0c6082c0c8
R13: 00007f0c6082c160 R14: 0000000000000004 R15: 0000000000000000
INFO: task syz-executor.4:16509 blocked for more than 145 seconds.
      Tainted: G        W         5.14.0-rc1-next-20210715-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:28832 pid:16509 ppid:  8486 flags:0x00000004
Call Trace:
 context_switch kernel/sched/core.c:4700 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5957
 schedule+0xd3/0x270 kernel/sched/core.c:6036
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6095
 __mutex_lock_common kernel/locking/mutex.c:1036 [inline]
 __mutex_lock+0xa46/0x1300 kernel/locking/mutex.c:1096
 genl_lock net/netlink/genetlink.c:33 [inline]
 genl_rcv_msg+0x3e0/0x580 net/netlink/genetlink.c:798
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:723
 __sys_sendto+0x21c/0x320 net/socket.c:2019
 __do_sys_sendto net/socket.c:2031 [inline]
 __se_sys_sendto net/socket.c:2027 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2027
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x41956c
RSP: 002b:00007f0c6082c020 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f0c6082c110 RCX: 000000000041956c
RDX: 000000000000001c RSI: 00007f0c6082c160 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f0c6082c074 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f0c6082c0c8
R13: 00007f0c6082c160 R14: 0000000000000004 R15: 0000000000000000
INFO: task systemd-udevd:16512 blocked for more than 145 seconds.
      Tainted: G        W         5.14.0-rc1-next-20210715-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:systemd-udevd   state:D stack:28504 pid:16512 ppid:  4877 flags:0x00000000
Call Trace:
 context_switch kernel/sched/core.c:4700 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5957
 schedule+0xd3/0x270 kernel/sched/core.c:6036
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6095
 __mutex_lock_common kernel/locking/mutex.c:1036 [inline]
 __mutex_lock+0xa46/0x1300 kernel/locking/mutex.c:1096
 nbd_open+0x7d/0x8a0 drivers/block/nbd.c:1479
 blkdev_get_whole+0xa1/0x420 fs/block_dev.c:1251
 blkdev_get_by_dev.part.0+0x30c/0xdd0 fs/block_dev.c:1415
 blkdev_get_by_dev fs/block_dev.c:1504 [inline]
 blkdev_open+0x295/0x300 fs/block_dev.c:1510
 do_dentry_open+0x4c8/0x11d0 fs/open.c:826
 do_open fs/namei.c:3374 [inline]
 path_openat+0x1c23/0x27f0 fs/namei.c:3507
 do_filp_open+0x1aa/0x400 fs/namei.c:3534
 do_sys_openat2+0x16d/0x420 fs/open.c:1204
 do_sys_open fs/open.c:1220 [inline]
 __do_sys_open fs/open.c:1228 [inline]
 __se_sys_open fs/open.c:1224 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1224
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f54530f9840
RSP: 002b:00007ffc39f42e78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00005607c34ac190 RCX: 00007f54530f9840
RDX: 00005607c2b91fe3 RSI: 00000000000a0800 RDI: 00005607c34a9f90
RBP: 00007ffc39f42ff0 R08: 00005607c2b91670 R09: 0000000000000010
R10: 00005607c2b91d0c R11: 0000000000000246 R12: 00007ffc39f42f40
R13: 00005607c34980e0 R14: 0000000000000003 R15: 000000000000000e
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 1643 Comm: khungtaskd Tainted: G        W         5.14.0-rc1-next-20210715-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline]
 watchdog+0xd3e/0xf50 kernel/hung_task.c:339
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:553