INFO: task syz-executor:25791 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:24048 pid:25791 tgid:25791 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1364
deactivate_locked_super+0xc1/0x1b0 fs/super.c:476
deactivate_super fs/super.c:509 [inline]
deactivate_super+0xe7/0x110 fs/super.c:505
cleanup_mnt+0x21f/0x450 fs/namespace.c:1312
task_work_run+0x150/0x240 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:67 [inline]
exit_to_user_mode_loop+0x107/0x4f0 kernel/entry/common.c:98
__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:318 [inline]
do_syscall_64+0x6f2/0x830 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f733a79e097
RSP: 002b:00007ffdae490758 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f733a8321ca RCX: 00007f733a79e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdae490810
RBP: 00007ffdae490810 R08: 00007ffdae491810 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdae4918a0
R13: 00007f733a8321ca R14: 00000000000cd13b R15: 00007ffdae4918e0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e5420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e5420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e7e5420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/5616:
2 locks held by getty/15757:
#0: ffff888033c660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900096992e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
2 locks held by syz.2.8194/25772:
#0: ffffffff906bff08 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec62400 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1938
2 locks held by syz-executor/25791:
#0: ffff888055f660d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888055f660d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888055f660d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff888055f660d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec62400 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.3.9326/29092:
#0: ffff8880438620d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880438620d8 (&type->s_umount_key#52){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880438620d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff8880438620d8 (&type->s_umount_key#52){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec62400 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.5.10053/31298:
1 lock held by syz.7.10105/31456:
=============================================
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 04/18/2026
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:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 31298 Comm: syz.5.10053 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:114 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0x6e/0x1e0 mm/kasan/generic.c:200
Code: 4c 8d 54 37 ff 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 49 c1 e9 03 48 01 c5 49 01 c1 48 89 e8 49 8d 59 01 <48> 89 da 48 29 ea 48 83 fa 10 0f 8e db 00 00 00 41 89 eb 41 83 e3
RSP: 0000:ffffc90005fcea80 EFLAGS: 00000282
RAX: fffff9400025e1a8 RBX: fffff9400025e1a9 RCX: ffffffff824f701f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea00012f0d40
RBP: fffff9400025e1a8 R08: 0000000000000000 R09: fffff9400025e1a8
R10: ffffea00012f0d47 R11: 0000000000000000 R12: 0000000000005a7c
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000005a7c
FS: 00007f68779966c0(0000) GS:ffff888124371000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c08ff8 CR3: 00000000348cc000 CR4: 00000000003526f0
Call Trace:
instrument_atomic_read include/linux/instrumented.h:82 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
folio_test_head include/linux/page-flags.h:843 [inline]
folio_test_large include/linux/page-flags.h:864 [inline]
folio_order include/linux/mm.h:1724 [inline]
shmem_add_to_page_cache+0x28f/0xcd0 mm/shmem.c:885
shmem_alloc_and_add_folio+0x558/0xd40 mm/shmem.c:2001
shmem_get_folio_gfp+0x6ab/0x1900 mm/shmem.c:2564
shmem_get_folio mm/shmem.c:2670 [inline]
shmem_write_begin+0x1a4/0x420 mm/shmem.c:3303
generic_perform_write+0x292/0xa40 mm/filemap.c:4325
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3478
__kernel_write_iter+0x2ac/0x920 fs/read_write.c:621
dump_emit_page fs/coredump.c:1304 [inline]
dump_user_range+0x3f9/0xad0 fs/coredump.c:1378
elf_core_dump+0x2d5f/0x3d10 fs/binfmt_elf.c:2109
coredump_write fs/coredump.c:1053 [inline]
do_coredump fs/coredump.c:1132 [inline]
vfs_coredump+0x29a0/0x5770 fs/coredump.c:1206
get_signal+0x2162/0x2210 kernel/signal.c:3022
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
irqentry_exit+0x410/0x7e0 kernel/entry/common.c:162
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 002b:000000000000000b EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f6876e15fa0 RCX: 00007f6876b9ce59
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000020003b46
RBP: 00007f6876c32d6f R08: fffffffffffffffe R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6876e16038 R14: 00007f6876e15fa0 R15: 00007fffafdc93d8