INFO: task syz.0.1030:9603 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1030 state:D stack:26632 pid:9603 tgid:9603 ppid:5869 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1187
__down_write_common kernel/locking/rwsem.c:1319 [inline]
__down_write kernel/locking/rwsem.c:1328 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1593
mmap_write_lock include/linux/mmap_lock.h:356 [inline]
userfaultfd_release_all+0x15a/0x5e0 mm/userfaultfd.c:2055
userfaultfd_release+0xe7/0x1b0 fs/userfaultfd.c:868
__fput+0x449/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fecc638e9a9
RSP: 002b:00007ffd68042908 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fecc65b7ba0 RCX: 00007fecc638e9a9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fecc65b7ba0 R08: 0000000000000000 R09: 0000000a68042bff
R10: 00007fecc65b7ac0 R11: 0000000000000246 R12: 0000000000070f3c
R13: 00007ffd68042a00 R14: ffffffffffffffff R15: 00007ffd68042a20
INFO: task syz.0.1030:9608 blocked for more than 144 seconds.
Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1030 state:D stack:28936 pid:9608 tgid:9603 ppid:5869 task_flags:0x40044c flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108
rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1088
__down_read_common kernel/locking/rwsem.c:1263 [inline]
__down_read kernel/locking/rwsem.c:1276 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1541
mmap_read_lock include/linux/mmap_lock.h:412 [inline]
exit_mm+0xcc/0x2c0 kernel/exit.c:557
do_exit+0x648/0x2300 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fecc638e9a9
RSP: 002b:00007fecc41f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: fffffffffffffffc RBX: 00007fecc65b6080 RCX: 00007fecc638e9a9
RDX: 000000000300000a RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fecc6410d69 R08: 0000000000000003 R09: 0000000093771000
R10: 0000000000022052 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fecc65b6080 R15: 00007ffd680427a8
Showing all locks held in the system:
2 locks held by kworker/0:0/9:
#0: ffff88801a880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801a880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc900000e7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900000e7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
1 lock held by khungtaskd/31:
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5605:
#0: ffff8880338350a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/0:5/5935:
1 lock held by syz.0.1030/9603:
#0: ffff88807fb36d60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:356 [inline]
#0: ffff88807fb36d60 (&mm->mmap_lock){++++}-{4:4}, at: userfaultfd_release_all+0x15a/0x5e0 mm/userfaultfd.c:2055
2 locks held by syz.0.1030/9607:
1 lock held by syz.0.1030/9608:
#0: ffff88807fb36d60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline]
#0: ffff88807fb36d60 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557
1 lock held by syz.5.1191/10185:
1 lock held by udevd/10819:
#0: ffff8880b8739f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
3 locks held by syz-executor/11340:
#0: ffff88807e688dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff88807e688dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715
#1: ffff88807e6880b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5282
#2: ffffffff8e543338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8e543338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:967
1 lock held by syz.3.1568/11491:
1 lock held by syz.1.1571/11510:
2 locks held by dhcpcd-run-hook/11547:
#0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
#1: ffff8880b8624008 (per_cpu_ptr(&psi_seq, cpu)){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:937
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
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: 10185 Comm: syz.5.1191 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217
Code: 24 65 48 8b 0c 25 08 50 e7 92 65 8b 15 08 4f 27 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c <8b> 91 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48
RSP: 0018:ffffc9000b01eea0 EFLAGS: 00000246
RAX: ffffffff822e888d RBX: ffffea000111f180 RCX: ffff888026003c00
RDX: 0000000000000000 RSI: ffffffff8c04d3e0 RDI: ffffffff8c04d3a0
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822e884a
R10: dffffc0000000000 R11: ffffed100d21eae2 R12: dffffc0000000000
R13: ffffea000111f100 R14: ffffffff822e884a R15: ffffea000111f1b0
FS: 0000000000000000(0000) GS:ffff8881257ab000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005579c18ca950 CR3: 0000000097a40000 CR4: 00000000003526f0
Call Trace:
rcu_read_lock include/linux/rcupdate.h:842 [inline]
__page_table_check_zero+0xfd/0x530 mm/page_table_check.c:138
page_table_check_free include/linux/page_table_check.h:43 [inline]
free_pages_prepare mm/page_alloc.c:1396 [inline]
free_unref_folios+0xdd1/0x1520 mm/page_alloc.c:2952
folios_put_refs+0x559/0x640 mm/swap.c:997
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1261 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1389
evict+0x501/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
shrink_kill+0xa9/0x2c0 fs/dcache.c:1114
shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1141
shrink_dcache_parent+0xa1/0x2c0 fs/dcache.c:-1
do_one_tree+0x23/0xe0 fs/dcache.c:1604
shrink_dcache_for_umount+0xa0/0x170 fs/dcache.c:1621
generic_shutdown_super+0x67/0x2c0 fs/super.c:621
kill_anon_super fs/super.c:1282 [inline]
kill_litter_super+0x76/0xb0 fs/super.c:1292
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1378
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f26c43c1265
Code: Unable to access opcode bytes at 0x7f26c43c123b.
RSP: 002b:00007f26c21f5f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f26c45b5fa0 RCX: 00007f26c43c1265
RDX: 00007f26c21f5fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f26c4410d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f26c45b5fa0 R15: 00007fffed6aeef8