INFO: task syz-executor:12231 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-executor state:D stack:21880 pid:12231 tgid:12231 ppid:1 task_flags:0x400140 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_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 kthread_stop+0x194/0x5c0 kernel/kthread.c:790 bch2_copygc_stop+0x4b/0x120 fs/bcachefs/movinggc.c:436 __bch2_fs_read_only+0x4a/0x4f0 fs/bcachefs/super.c:303 bch2_fs_read_only+0x403/0xa40 fs/bcachefs/super.c:389 __bch2_fs_stop+0xc9/0x8f0 fs/bcachefs/super.c:700 generic_shutdown_super+0x132/0x2c0 fs/super.c:643 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2586 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 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: 0033:0x7f0f5ed8fcd7 RSP: 002b:00007ffc7264e6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f0f5ee10b55 RCX: 00007f0f5ed8fcd7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc7264e780 RBP: 00007ffc7264e780 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc7264f810 R13: 00007f0f5ee10b55 R14: 0000000000063671 R15: 00007ffc7264f850 Showing all locks held in the system: 5 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/31: #0: ffffffff8e13d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 3 locks held by kworker/u8:3/49: 5 locks held by kworker/u8:9/3985: 2 locks held by getty/5605: #0: ffff8880302fe0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/12227: 2 locks held by syz-executor/12231: #0: ffff88805519e0e0 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805519e0e0 (&type->s_umount_key#78){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805519e0e0 (&type->s_umount_key#78){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff88805c000278 (&c->state_lock){++++}-{4:4}, at: class_rwsem_write_constructor include/linux/rwsem.h:257 [inline] #1: ffff88805c000278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xc1/0x8f0 fs/bcachefs/super.c:699 2 locks held by bch-copygc/loop/13075: #0: ffff88805c0043a8 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #0: ffff88805c0043a8 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #0: ffff88805c0043a8 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3293 #1: ffff88805c026710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x53f/0x1e00 fs/bcachefs/btree_update_interior.c:1196 1 lock held by udevd/15646: #0: ffff8880b8739f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 ============================================= 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: 3985 Comm: kworker/u8:9 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 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker RIP: 0010:__kasan_check_byte+0x7/0x40 mm/kasan/common.c:555 Code: da fe ff ff 48 ff c8 49 89 c4 e9 cf fe ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 56 53 <48> 89 f3 49 89 fe e8 5e 14 00 00 84 c0 75 16 be 01 00 00 00 4c 89 RSP: 0018:ffffc9000d0d72a0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 635cf20cd20cd300 RDX: 0000000000000000 RSI: ffffffff8172b1b2 RDI: ffffffff8e13d8a0 RBP: ffffffff8172b195 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc9000d0d7478 R11: ffffffff81ac4660 R12: 0000000000000002 R13: ffffffff8e13d8a0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125be3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d80aff8 CR3: 000000007ee7c000 CR4: 00000000003526f0 Call Trace: kasan_check_byte include/linux/kasan.h:399 [inline] lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5845 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4281 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:578 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:669 alloc_skb include/linux/skbuff.h:1336 [inline] wg_socket_send_buffer_to_peer+0x38/0x1c0 drivers/net/wireguard/socket.c:192 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x1db/0x320 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 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 vkms_vblank_simulate: vblank timer overrun