INFO: task syz.2.311:7127 blocked for more than 143 seconds.
Not tainted 6.16.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.311 state:D stack:23152 pid:7127 tgid:7127 ppid:5838 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
request_wait_answer fs/fuse/dev.c:565 [inline]
__fuse_request_send fs/fuse/dev.c:579 [inline]
__fuse_simple_request+0xf15/0x18d0 fs/fuse/dev.c:673
fuse_simple_request fs/fuse/fuse_i.h:1237 [inline]
fuse_flush+0x5d4/0x800 fs/fuse/file.c:475
filp_flush+0xba/0x190 fs/open.c:1549
filp_close+0x1d/0x40 fs/open.c:1562
__range_close fs/file.c:752 [inline]
__do_sys_close_range fs/file.c:811 [inline]
__se_sys_close_range+0x359/0x650 fs/file.c:775
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f897698ebe9
RSP: 002b:00007ffedf8a7268 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007f8976bb7da0 RCX: 00007f897698ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f8976bb7da0 R08: 000000000000011c R09: 0000000fdf8a755f
R10: 00000000003ffcc0 R11: 0000000000000246 R12: 0000000000038ae8
R13: 00007f8976bb6090 R14: ffffffffffffffff R15: 00007ffedf8a7380
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/1:1/43:
2 locks held by kworker/u8:7/4591:
#0: ffff888020332148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff888020332148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000dd7fbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000dd7fbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
2 locks held by getty/5598:
#0: ffff88814c3b20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036c52f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz.3.662/8507:
#0: ffffffff8f4fd310 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570
#1: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160
2 locks held by syz.5.664/8516:
#0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:822
#1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 4591 Comm: kworker/u8:7 Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: iou_exit io_ring_exit_work
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:109 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:-1 [inline]
RIP: 0010:unwind_next_frame+0x33c/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: ff 48 8d 1c 08 48 81 c3 e8 7a ae 8f 48 81 fb e8 7a ae 8f 0f 83 48 11 00 00 48 c7 c0 e8 7a ae 8f 49 29 c5 48 c7 c6 08 10 27 90 <49> c1 fd 02 4a 8d 14 6d 00 00 00 00 4c 01 ea 48 01 d2 48 01 f2 48
RSP: 0018:ffffc9000dd7f3d8 EFLAGS: 00000206
RAX: ffffffff8fb74a80 RBX: ffffffff8fb74a84 RCX: ffffffff8fb74a88
RDX: ffffffff8fb74a54 RSI: ffffffff9034472a RDI: ffffffff8be1b9e0
RBP: ffffffff8fb74a88 R08: 000000000000000d R09: ffffffff8172aae5
R10: ffffc9000dd7f4f8 R11: ffffffff81acfd40 R12: ffffffff81acfceb
R13: 0000000000000030 R14: ffffc9000dd7f4a8 R15: ffffffff8fb74a84
FS: 0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa94ad83ad8 CR3: 0000000075f9a000 CR4: 00000000003526f0
DR0: 0000000000000001 DR1: 0000000000000002 DR2: 0000000000000008
DR3: 1000000100000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
slab_free_hook mm/slub.c:2342 [inline]
slab_free mm/slub.c:4643 [inline]
kmem_cache_free+0x2f6/0x400 mm/slub.c:4745
__io_req_caches_free+0x8f/0x140 io_uring/io_uring.c:2709
io_req_caches_free+0x21/0x30 io_uring/io_uring.c:2721
io_ring_exit_work+0x415/0x930 io_uring/io_uring.c:2919
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245