INFO: task syz.2.870:10513 blocked for more than 144 seconds.
Not tainted 6.16.0-rc3-syzkaller-00057-g92ca6c498a5e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.870 state:D stack:28072 pid:10513 tgid:10505 ppid:5815 task_flags:0x400640 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6878
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:116
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:264
coredump_wait fs/coredump.c:504 [inline]
do_coredump+0x8fa/0x4f10 fs/coredump.c:686
get_signal+0x22e3/0x26d0 kernel/signal.c:3019
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f64cb18e929
RSP: 002b:00007f64cbf0f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 00000000000000ca RBX: 00007f64cb3b6248 RCX: 00007f64cb18e929
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f64cb3b624c
RBP: 00007f64cb3b6240 R08: 00007f64cbfd8000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f64cb3b624c
R13: 0000000000000000 R14: 00007ffc6f826540 R15: 00007ffc6f826628
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c4940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
3 locks held by kworker/1:2/1202:
#0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc900041afd10 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffffffff8e5cfe00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3786
2 locks held by getty/5566:
#0: ffff888036af20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by syz.2.870/10512:
2 locks held by syz.1.1187/12165:
#0: ffffffff90336b90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570
#1: ffffffff8e5cfe00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3786
1 lock held by syz.3.1189/12155:
#0: ffffffff8e5cfe00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3786
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-syzkaller-00057-g92ca6c498a5e #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/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+0xf70/0x12c0 kernel/hung_task.c:470
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x5d4/0x6f0 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: 10512 Comm: syz.2.870 Not tainted 6.16.0-rc3-syzkaller-00057-g92ca6c498a5e #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:check_preemption_disabled+0x2d/0xe0 lib/smp_processor_id.c:19
Code: 53 48 83 ec 08 65 8b 1d 45 4c 4c 08 65 8b 05 3a 4c 4c 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c e9 94 de 02 00 9c <58> f6 c4 02 74 ea 48 89 fd 65 48 8b 05 fa 4b 4c 08 f6 40 2f 04 74
RSP: 0018:ffffc9001019eed0 EFLAGS: 00000046
RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffffc900101a0001
RDX: 0000000000000000 RSI: ffffffff8df0be4f RDI: ffffffff8c157ba0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000084eaf R12: ffffffff816acad4
R13: 0000000000000206 R14: ffff888071d9a440 R15: ffffc9001019efec
FS: 00007f64cbf956c0(0000) GS:ffff888124752000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc0ebf80ab8 CR3: 0000000063b81000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:468 [inline]
lock_release+0x9c/0x2f0 kernel/locking/lockdep.c:5891
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4328 [inline]
__kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4347
kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601
__alloc_skb+0x166/0x380 net/core/skbuff.c:670
alloc_skb include/linux/skbuff.h:1336 [inline]
alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6665
sock_alloc_send_pskb+0x7fb/0x990 net/core/sock.c:2999
unix_dgram_sendmsg+0x41a/0x1840 net/unix/af_unix.c:2072
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
sock_write_iter+0x4ff/0x5b0 net/socket.c:1131
io_write+0x6bb/0x1660 io_uring/rw.c:1160
__io_issue_sqe+0xe8/0x7c0 io_uring/io_uring.c:1738
io_issue_sqe+0x86/0xe50 io_uring/io_uring.c:1761
io_queue_sqe io_uring/io_uring.c:1968 [inline]
io_req_task_submit+0x119/0x1f0 io_uring/io_uring.c:1380
io_poll_task_func+0x942/0x1240 io_uring/poll.c:339
io_handle_tw_list+0x155/0x500 io_uring/io_uring.c:1067
tctx_task_work_run+0xac/0x380 io_uring/io_uring.c:1132
tctx_task_work+0x7a/0xd0 io_uring/io_uring.c:1150
task_work_run+0x150/0x240 kernel/task_work.c:227
get_signal+0x1d1/0x26d0 kernel/signal.c:2807
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f64cb18e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f64cbf95038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: 0000000000001000 RBX: 00007f64cb3b6160 RCX: 00007f64cb18e929
RDX: 0000000000003e80 RSI: 000000000000601f RDI: 0000000000000006
RBP: 00007f64cb210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f64cb3b6160 R15: 00007ffc6f826628
vkms_vblank_simulate: vblank timer overrun