INFO: task syz.4.3830:21235 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3830 state:D stack:26280 pid:21235 ppid:20078 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
write_ports+0xb7/0xfa0 fs/nfsd/nfsctl.c:843
nfsctl_transaction_write+0x10c/0x150 fs/nfsd/nfsctl.c:113
vfs_write+0x299/0x9a0 fs/read_write.c:582
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3b96b9de99
RSP: 002b:00007f3b97a24028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3b96e25fa0 RCX: 00007f3b96b9de99
RDX: 0000000000000005 RSI: 0000200000000300 RDI: 0000000000000003
RBP: 00007f3b96c33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3b96e26038 R14: 00007f3b96e25fa0 R15: 00007fff07f69d78
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:9/4257:
1 lock held by klogd/5131:
#0: ffff8880b8f3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
2 locks held by getty/5528:
#0: ffff88802d22d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by syz.0.3495/19843:
#0: ffff888059c5cd48 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff88801fb94418 (sb_writers#29){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffffffff8d3e17a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb7/0xfa0 fs/nfsd/nfsctl.c:843
3 locks held by syz.4.3830/21235:
#0: ffff88805cb8bc48 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff8880603d0418 (sb_writers#29){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffffffff8d3e17a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb7/0xfa0 fs/nfsd/nfsctl.c:843
3 locks held by syz.6.3980/21934:
#0: ffff8880760a34c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff888051f52418 (sb_writers#29){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffffffff8d3e17a8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x96/0xe00 fs/nfsd/nfsctl.c:676
2 locks held by syz.3.3992/22030:
#0: ffff888063df60e0 (&type->s_umount_key#94){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff888063df60e0 (&type->s_umount_key#94){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff888063df60e0 (&type->s_umount_key#94){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffffffff8d3e17a8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x53/0x1a0 fs/nfsd/nfssvc.c:638
3 locks held by syz.5.4295/23488:
#0: ffff88807e4700c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
#1: ffff88807783a418 (sb_writers#29){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#2: ffffffff8d3e17a8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x65/0xab0 fs/nfsd/nfssvc.c:788
1 lock held by sed/23719:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 23724 Comm: cmp Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x30/0x80 kernel/kcov.c:320
Code: 04 24 65 48 8b 0d 20 3f 7c 7e 65 8b 15 21 3f 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 1c 16 00 00 00 74 4e <8b> 91 f8 15 00 00 83 fa 03 75 43 48 8b 91 00 16 00 00 44 8b 89 fc
RSP: 0018:ffffc90003507798 EFLAGS: 00000246
RAX: ffffffff8a7a7582 RBX: dffffc0000000000 RCX: ffff88802c539e00
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000000
RBP: ffffc90003507950 R08: ffff88802c539e00 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: 000000000000000e
R13: ffffffffffffffff R14: ffff88804094fa00 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f78a99af440 CR3: 00000000421eb000 CR4: 00000000003506f0
Call Trace:
mas_data_end lib/maple_tree.c:1479 [inline]
mt_validate_nulls lib/maple_tree.c:7190 [inline]
mt_validate+0x3ff2/0x4410 lib/maple_tree.c:7237
validate_mm+0xc6/0x450 mm/mmap.c:288
mmap_region+0x192c/0x2090 mm/mmap.c:2947
do_mmap+0x98f/0x10a0 mm/mmap.c:1385
vm_mmap_pgoff+0x1c4/0x3f0 mm/util.c:556
ksys_mmap_pgoff+0x4c9/0x720 mm/mmap.c:1431
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f78a9c89242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007fffcb3c2a28 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f78a9c89242
RDX: 0000000000000001 RSI: 0000000000010888 RDI: 0000000000000000
RBP: 0000000000000802 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000802 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78a9c66580 R14: 00007fffcb3c2ea0 R15: 00000ffff9678548