INFO: task syz.4.2111:12393 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.4.2111 state:D stack:28552 pid:12393 tgid:12389 ppid:5629 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x1b4d/0x59e0 kernel/sched/core.c:7240
__schedule_loop kernel/sched/core.c:7317 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7332
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7389
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:708
nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:114
vfs_write+0x296/0xba0 fs/read_write.c:685
ksys_write+0x150/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c71f9e0d9
RSP: 002b:00007f5c72e51028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5c72226090 RCX: 00007f5c71f9e0d9
RDX: 0000000000000002 RSI: 00002000000001c0 RDI: 0000000000000005
RBP: 00007f5c72035024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5c72226128 R14: 00007f5c72226090 R15: 00007ffdd490dbf8
Showing all locks held in the system:
locks held by pr/ttyS0/16: 1, last CPU#1:
#0: ffffffff8ea36478 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8ea36478 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8ea36478 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
locks held by khungtaskd/32: 1, last CPU#1:
#0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by getty/5372: 2, on CPU#0:
#0: ffff88803621c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5622: 1, last CPU#0:
#0: ffff88802b074460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
locks held by syz-executor/5624: 4, last CPU#0:
#0: ffff888066968460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
#1: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: __page_table_check_zero+0x6c/0x430 mm/page_table_check.c:138
#2: ffffc90000007cc0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x5f0 kernel/time/timer.c:1745
#3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.4.2111/12392: 3, on CPU#0:
#0: ffff88802aabed30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff88801ffd8460 (sb_writers#26){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2754 [inline]
#1: ffff88801ffd8460 (sb_writers#26){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8ee94e00 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:867
locks held by syz.4.2111/12393: 3, on CPU#1:
#0: ffff88802b117970 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff88801ffd8460 (sb_writers#26){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2754 [inline]
#1: ffff88801ffd8460 (sb_writers#26){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8ee94e00 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x95/0xe30 fs/nfsd/nfsctl.c:708
locks held by syz.5.2659/14256: 1, last CPU#1:
#0: ffff888053e90e70 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2575
locks held by syz.3.2663/14262: 1, last CPU#0:
#0: ffff88801b051078 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
#0: ffff88801b051078 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323
locks held by syz.6.2662/14264: 2, last CPU#1:
#0: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#0: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:815
#1: ffffffff8ea36478 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#1: ffffffff8ea36478 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#1: ffffffff8ea36478 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
=============================================
NMI backtrace for cpu 1
CPU: 1 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 07/24/2026
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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5624 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:match_held_lock+0x0/0xb0 kernel/locking/lockdep.c:5322
Code: 67 48 0f b9 3a 90 31 db 48 89 d8 5b 41 5e 41 5f e9 45 00 03 00 cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 56 53 bb 01 00 00 00 48 39 77 10 74 6d 0f b7 47 22 a9 e0 ff 00
RSP: 0018:ffffc90000007988 EFLAGS: 00000083
RAX: 0000000000000004 RBX: ffff88807f4a2b18 RCX: 0000000000000101
RDX: 0000000000082820 RSI: ffff8880b8644190 RDI: ffff88807f4a2b18
RBP: 00000000ffffffff R08: 7b00000000000000 R09: 0000000000000000
R10: 0000000000008000 R11: ffff8880b8644190 R12: 0000000000000246
R13: ffff88807f4a1f40 R14: ffff8880b8644190 R15: 0000000000000001
FS: 000055557e50b500(0000) GS:ffff888124f0a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb59ee24ff8 CR3: 000000005dda6000 CR4: 00000000003526f0
DR0: 0000000000010000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__lock_is_held kernel/locking/lockdep.c:5620 [inline]
lock_is_held_type+0x89/0x150 kernel/locking/lockdep.c:5982
lock_is_held include/linux/lockdep.h:249 [inline]
__pcs_replace_empty_main+0x58/0x6c0 mm/slub.c:4722
alloc_from_pcs mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:4984 [inline]
kmem_cache_alloc_node_noprof+0x437/0x610 mm/slub.c:5068
kmalloc_reserve net/core/skbuff.c:615 [inline]
__alloc_skb+0x27a/0x7a0 net/core/skbuff.c:715
alloc_skb include/linux/skbuff.h:1384 [inline]
ndisc_alloc_skb+0xa0/0x480 net/ipv6/ndisc.c:421
ndisc_send_rs+0x288/0x6b0 net/ipv6/ndisc.c:708
addrconf_rs_timer+0x2d2/0x6c0 net/ipv6/addrconf.c:4072
call_timer_fn+0x18d/0x5f0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x226/0x860 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767
irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x80 kernel/kcov.c:212
Code: 8b 3d 94 d6 8a 0c 48 89 de 5b e9 c3 ea 62 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 28 b6 a9 11 65 48 8b 15 28 b6 a9 11 f7 c2 00 01 00 ff
RSP: 0018:ffffc90003d37550 EFLAGS: 00000297
RAX: ffffffff8241ee58 RBX: 0000000000000001 RCX: ffff88807f4a1f40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: cf00000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb5c8a0 R12: ffffea000128a440
R13: dffffc0000000000 R14: 000000000004a291 R15: ffffffff8241ed6c
__page_table_check_zero+0x158/0x430 mm/page_table_check.c:139
page_table_check_free include/linux/page_table_check.h:46 [inline]
__free_pages_prepare mm/page_alloc.c:1419 [inline]
free_unref_folios+0xdd2/0x14e0 mm/page_alloc.c:3022
folios_put_refs+0x9e9/0xb30 mm/folio.c:1034
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1160
shmem_truncate_range mm/shmem.c:1288 [inline]
shmem_evict_inode+0x247/0xae0 mm/shmem.c:1419
evict+0x624/0xb50 fs/inode.c:822
filename_unlinkat+0x43f/0x610 fs/namei.c:5723
__do_sys_unlink fs/namei.c:5754 [inline]
__se_sys_unlink+0x2e/0x140 fs/namei.c:5751
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff02879d1c7
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffeb9d96e48 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff02879d1c7
RDX: 00007ffeb9d96e70 RSI: 00007ffeb9d96f00 RDI: 00007ffeb9d96f00
RBP: 00007ffeb9d96f00 R08: 00007ffeb9d97f00 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffeb9d97f90
R13: 00007ff028834474 R14: 00000000000a226f R15: 00007ffeb9d97fd0