INFO: task syz-executor:5622 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22088 pid:5622 tgid:5622 ppid:1 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
nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1372
deactivate_locked_super+0xbe/0x110 fs/super.c:586
cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7d9b19f3d7
RSP: 002b:00007ffc52274cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f7d9b234d23 RCX: 00007f7d9b19f3d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc52274db0
RBP: 00007ffc52274db0 R08: 00007ffc52275db0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc52275e40
R13: 00007f7d9b234d23 R14: 000000000006f961 R15: 00007ffc52275e80
Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by syz-executor/5610: 2, on CPU#0:
#0: ffff888028d580e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888028d580e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff888028d580e8 (&type->s_umount_key#95){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f09f860 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/5622: 2, on CPU#1:
#0: ffff88805330c0e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88805330c0e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88805330c0e8 (&type->s_umount_key#95){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f09f860 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/12295: 2, on CPU#1:
#0: ffff888021f5e0e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888021f5e0e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff888021f5e0e8 (&type->s_umount_key#95){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f09f860 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz.5.4165/16721: 3, on CPU#0:
#0: ffff88807f0807f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff8880511ae460 (sb_writers#30){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff8880511ae460 (sb_writers#30){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8f09f860 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:867
locks held by getty/17118: 2, on CPU#1:
#0: ffff8880363ed0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032662e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/17185: 4, last CPU#0:
#0: ffffffff8ee36650 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff8ee36650 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10a/0x480 kernel/fork.c:1595
#1: ffff88807e64b440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#1: ffff88807e64b440 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716
#2: ffff888035330f80 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
#2: ffff888035330f80 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723
#3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by syz-executor/17623: 2, on CPU#1:
#0: ffff88807985c0e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807985c0e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807985c0e8 (&type->s_umount_key#95){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f09f860 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/19126: 2, on CPU#0:
#0: ffff8880784e60e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880784e60e8 (&type->s_umount_key#95){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff8880784e60e8 (&type->s_umount_key#95){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f09f860 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz-executor/19697: 4, last CPU#0:
#0: ffffffff8ee36650 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff8ee36650 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10a/0x480 kernel/fork.c:1595
#1: ffff8880360a0f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#1: ffff8880360a0f80 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716
#2: ffff888035337180 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
#2: ffff888035337180 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723
#3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by syz.3.5590/20764: 5, last CPU#0:
#0: ffffffff9ad93d68 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:164 [inline]
#0: ffffffff9ad93d68 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
#0: ffffffff9ad93d68 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x33d/0xa40 drivers/infiniband/core/netlink.c:259
#1: ffffffff8ffb0b28 (link_ops_rwsem){++++}-{4:4}, at: nldev_newlink+0x42b/0x650 drivers/infiniband/core/nldev.c:1848
#2: ffffffff8ffa1c48 (devices_rwsem){++++}-{4:4}, at: enable_device_and_get+0xff/0x3e0 drivers/infiniband/core/device.c:1365
#3: ffffffff8ffa1e08 (rdma_nets_rwsem){++++}-{4:4}, at: add_compat_devs drivers/infiniband/core/device.c:1058 [inline]
#3: ffffffff8ffa1e08 (rdma_nets_rwsem){++++}-{4:4}, at: enable_device_and_get+0x27c/0x3e0 drivers/infiniband/core/device.c:1381
#4: ffff888083255020 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:976
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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