INFO: task syz.0.4872:23501 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.0.4872 state:D stack:28728 pid:23501 tgid:23500 ppid:17817 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7276
__schedule_loop kernel/sched/core.c:7353 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7368
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7425
__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: 0033:0x7f78d459e159
RSP: 002b:00007f78d54c9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f78d4825fa0 RCX: 00007f78d459e159
RDX: 0000000000000005 RSI: 0000200000000500 RDI: 0000000000000003
RBP: 00007f78d4635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78d4826038 R14: 00007f78d4825fa0 R15: 00007ffc3e4150a8
Showing all locks held in the system:
locks held by pr/ttyS0/16: 1, last CPU#0:
#0: ffffffff8edd85b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8edd85b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8edd85b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291
locks held by khungtaskd/31: 1, last CPU#0:
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by getty/5363: 1, last CPU#1:
#0: ffff888033ce20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
locks held by syz-executor/18388: 1, last CPU#0:
#0: ffff888033dbece0 (&xt[i].mutex){+.+.}-{4:4}, at: xt_find_table_lock+0x5a/0x520 net/netfilter/x_tables.c:1336
locks held by kworker/0:7/22231: 5, last CPU#0:
#0: ffff88801fef4940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc9000402fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88802b3541d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802b3541d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4420 drivers/usb/core/hub.c:5912
#3: ffff888058a751d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#3: ffff888058a751d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1073
#4: ffffffff8edd85b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#4: ffffffff8edd85b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#4: ffffffff8edd85b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291
locks held by syz.1.4849/23433: 3, on CPU#1:
#0: ffff8880763775f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff8880569a0460 (sb_writers#22){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff8f2882c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:867
locks held by syz.0.4872/23501: 3, on CPU#1:
#0: ffff8880739a8d30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff888036e9a460 (sb_writers#22){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff8f2882c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:867
locks held by syz-executor/23559: 1, last CPU#1:
#0: ffff88807a71e460 (sb_writers#6){.+.+}-{0:0}, at: filename_unlinkat+0x1ad/0x730 fs/namei.c:5696
locks held by udevd/24661: 1, last CPU#1:
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: fast_dput+0x25/0x6f0 fs/dcache.c:938
locks held by udevd/24703: 1, last CPU#0:
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
locks held by syz.4.5274/25114: 2, last CPU#1:
#0: ffff888029fb03b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff888029fb03b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299
#1: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by syz.8.5277/25132: 2, last CPU#1:
#0: ffff88807c8c9078 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
#0: ffff88807c8c9078 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299
#1: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by dhcpcd-run-hook/25133: 1, last CPU#1:
#0: ffff88807c8cb6b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
#0: ffff88807c8cb6b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x22c/0xa00 mm/mmap.c:1323
=============================================
NMI backtrace for cpu 0
CPU: 0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 25133 Comm: dhcpcd-run-hook 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:lock_sequence+0xd3/0x110 kernel/locking/lockdep.c:6096
Code: e8 22 88 e9 09 b8 ff ff ff ff 65 0f c1 05 cd b4 a5 12 83 f8 01 75 27 9c 58 f6 c4 02 75 3d 41 f7 c6 00 02 00 00 74 01 fb 89 d8 <5b> 5d 41 5c 41 5d 41 5e c3 cc cc cc cc bb ff ff ff ff eb bb 90 0f
RSP: 0018:ffffc90006967988 EFLAGS: 00000206
RAX: 00000000000000b4 RBX: 00000000000000b4 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e3c5c3d RDI: ffffffff8c621080
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000300
R10: 0000000000000300 R11: 0000000000000001 R12: ffff88807c8cb6b8
R13: ffff88801fb04b00 R14: 0000000000000246 R15: ffffc90006967bb8
FS: 0000000000000000(0000) GS:ffff888123c5d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe7f909ff8 CR3: 000000007fbb7000 CR4: 00000000003526f0
Call Trace:
mas_lock_check+0xd2/0x1b0 lib/maple_tree.c:1187
mas_may_init_lock_check lib/maple_tree.c:1222 [inline]
mas_find+0x23/0x790 lib/maple_tree.c:5487
free_pgtables+0x37b/0xd80 mm/memory.c:411
exit_mmap+0x44c/0xa00 mm/mmap.c:1327
__mmput+0x12a/0x410 kernel/fork.c:1193
mmput+0x67/0x80 kernel/fork.c:1216
exit_mm kernel/exit.c:614 [inline]
do_exit+0x8b1/0x2ae0 kernel/exit.c:996
do_group_exit+0xd5/0x2a0 kernel/exit.c:1151
__do_sys_exit_group kernel/exit.c:1162 [inline]
__se_sys_exit_group kernel/exit.c:1160 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1160
x64_sys_call+0x1567/0x1570 arch/x86/include/generated/asm/syscalls_64.h:232
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: 0033:0x7fbcf431f6c5
Code: Unable to access opcode bytes at 0x7fbcf431f69b.
RSP: 002b:00007ffea44236f8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffea4423a04 RCX: 00007fbcf431f6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00007ffea44237f0 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffea4423a30 R14: 00007fbcf452f000 R15: 0000561484c98d98