INFO: task syz.0.1459:10013 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.0.1459 state:D stack:28216 pid:10013 tgid:10012 ppid:5598 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0xdd/0x2c0 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+0xccb/0x1bd0 kernel/locking/mutex.c:821
write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:867
nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:114
vfs_write+0x2aa/0x1050 fs/read_write.c:685
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4e2859e159
RSP: 002b:00007f4e2952c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4e28825fa0 RCX: 00007f4e2859e159
RDX: 0000000000000006 RSI: 0000200000000240 RDI: 0000000000000003
RBP: 00007f4e2863506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4e28826038 R14: 00007f4e28825fa0 R15: 00007ffd463f4cd8
INFO: task syz.0.1459:10023 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.0.1459 state:D stack:28728 pid:10023 tgid:10012 ppid:5598 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0xdd/0x2c0 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+0xccb/0x1bd0 kernel/locking/mutex.c:821
write_threads+0x288/0x600 fs/nfsd/nfsctl.c:436
nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:114
vfs_write+0x2aa/0x1050 fs/read_write.c:685
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4e2859e159
RSP: 002b:00007f4e2950b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4e28826090 RCX: 00007f4e2859e159
RDX: 0000000000000002 RSI: 0000200000000340 RDI: 0000000000000003
RBP: 00007f4e2863506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4e28826128 R14: 00007f4e28826090 R15: 00007ffd463f4cd8
Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#1:
#0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by khugepaged/37: 1, on CPU#1:
#0: ffffffff8ef56ec0 (lock#5){+.+.}-{4:4}, at: __lru_add_drain_all+0xcf/0x820 mm/folio.c:823
locks held by kworker/u8:9/309: 6, last CPU#1:
#0: ffff888021e99940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90002dafd08 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff888034cce0e8 (&type->s_umount_key#57){++++}-{4:4}, at: super_trylock_shared+0x21/0xf0 fs/super.c:670
#3: ffff888034cccc98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2560
#4: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#4: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#4: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: blk_mq_run_hw_queue+0x314/0x670 block/blk-mq.c:2368
#5: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#5: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#5: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#5: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
locks held by getty/5359: 2, on CPU#1:
#0: ffff8880350f30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032262e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by syz-executor/5610: 2, on CPU#0:
#0: ffff88802d0aa0e8 (&type->s_umount_key#89){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88802d0aa0e8 (&type->s_umount_key#89){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88802d0aa0e8 (&type->s_umount_key#89){+.+.}-{4:4}, at: deactivate_super fs/super.c:613 [inline]
#0: ffff88802d0aa0e8 (&type->s_umount_key#89){+.+.}-{4:4}, at: deactivate_super+0xe2/0x110 fs/super.c:610
#1: ffffffff8f289bc0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
locks held by syz.1.1423/9905: 3, on CPU#1:
#0: ffff888059a05eb0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88807e2be460 (sb_writers#24){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff8f289bc0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:867
locks held by syz.0.1459/10013: 3, on CPU#0:
#0: ffff88807ddaf430 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88802b92e460 (sb_writers#24){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff8f289bc0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:867
locks held by syz.0.1459/10023: 3, on CPU#0:
#0: ffff888071e389b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88802b92e460 (sb_writers#24){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff8f289bc0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x288/0x600 fs/nfsd/nfsctl.c:436
locks held by udevd/11672: 1, last CPU#0:
#0: ffff88801d2c7180 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1217
locks held by syz.7.1900/11676: 2, last CPU#1:
#0: ffffffff90cbc188 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff8edf84a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
locks held by syz.4.1918/11726: 5, on CPU#1:
#0: ffffffff90cbc188 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x323/0x7a0 net/core/net_namespace.c:578
#1: ffffffff908e3588 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1221
#2: ffffffff908e3308 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x2ff/0x590 drivers/infiniband/core/device.c:1226
#3: ffff88802a709020 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0x112/0x820 drivers/infiniband/core/device.c:976
#4: ffff88801d2c7180 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0xaa0 fs/kernfs/dir.c:825
locks held by fido_id/11723: 1, last CPU#1:
#0: ffff888034312800 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff888034312800 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579
locks held by syz-executor/11728: 2, last CPU#1:
#0: ffff8880370f5808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
#1: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: do_fault_around mm/memory.c:5957 [inline]
#1: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: do_read_fault mm/memory.c:5991 [inline]
#1: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: do_fault+0x9a8/0x1830 mm/memory.c:6134
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 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: 11724 Comm: syz.4.1918 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:__sanitizer_cov_trace_pc+0x4b/0x70 kernel/kcov.c:216
Code: 1e f6 c4 01 74 44 a9 00 00 00 0f 75 3d f7 c1 00 00 00 f0 75 35 8b 82 44 17 00 00 85 c0 74 2b 8b 82 18 17 00 00 83 f8 02 75 20 <48> 8b 8a 20 17 00 00 8b 92 1c 17 00 00 48 8b 01 48 83 c0 01 48 39
RSP: 0018:ffffc9000332f9f8 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88802ed6cb00 RSI: ffffffff8993dfb6 RDI: ffff88802ed6cb00
RBP: ffffc9000332fd90 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: ffffc9000332fdd4 R15: 0000000000000002
FS: 00007fa62bdf66c0(0000) GS:ffff888123b4e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000c00030 CR3: 000000007e4d3000 CR4: 00000000003526f0
Call Trace:
____sys_recvmsg+0x226/0x670 net/socket.c:2935
___sys_recvmsg+0x16a/0x1a0 net/socket.c:2975
do_recvmmsg+0x2f3/0x740 net/socket.c:3070
__sys_recvmmsg net/socket.c:3144 [inline]
__do_sys_recvmmsg net/socket.c:3167 [inline]
__se_sys_recvmmsg net/socket.c:3160 [inline]
__x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3160
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa62db9e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa62bdf6028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fa62de26090 RCX: 00007fa62db9e159
RDX: 0000000004000087 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fa62dc3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa62de26128 R14: 00007fa62de26090 R15: 00007fffac23d8c8