INFO: task syz.4.2517:15107 blocked for more than 144 seconds. Not tainted 6.6.94-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2517 state:D stack:28936 pid:15107 ppid:14447 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14e2/0x4580 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 rwsem_down_read_slowpath+0x4f8/0x840 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read kernel/locking/rwsem.c:1263 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1522 __super_lock fs/super.c:58 [inline] super_lock+0x167/0x360 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] iterate_supers+0x80/0x170 fs/super.c:977 ksys_sync+0x95/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8d7138e929 RSP: 002b:00007f8d721c6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f8d715b5fa0 RCX: 00007f8d7138e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f8d715b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8d715b5fa0 R15: 00007ffdcee38b48 Showing all locks held in the system: 5 locks held by kworker/u4:1/12: 1 lock held by khungtaskd/29: #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5531: #0: ffff88823bde00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/1:15/12241: 3 locks held by syz-executor/14118: #0: ffff88805faf20e0 (&type->s_umount_key#95){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805faf20e0 (&type->s_umount_key#95){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805faf20e0 (&type->s_umount_key#95){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffff8880b8e3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566 #2: ffff888018250018 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x69f/0x1020 kernel/workqueue.c:1764 1 lock held by syz-executor/14123: #0: ffff88801efa20e0 (&type->s_umount_key#83){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88801efa20e0 (&type->s_umount_key#83){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88801efa20e0 (&type->s_umount_key#83){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 1 lock held by syz.4.2517/15107: #0: ffff88801efa20e0 (&type->s_umount_key#83){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88801efa20e0 (&type->s_umount_key#83){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 4 locks held by syz-executor/15321: 1 lock held by syz.2.2798/16427: 3 locks held by dhcpcd-run-hook/16443: #0: ffff8880b8e3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566 #1: ffff8880b8f288c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39c/0x6d0 kernel/sched/psi.c:998 #2: ffff88806682a5b8 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88806682a5b8 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0x107/0x1e0 mm/pgtable-generic.c:375 1 lock held by syz.9.2804/16448: #0: ffffffff8cd35600 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4085 1 lock held by syz.3.2801/16460: #0: ffffffff8cd35738 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #0: ffffffff8cd35738 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 4 locks held by rm/16461: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 12431 Comm: kworker/u4:17 Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:216 Code: 20 24 7e 7e 65 8b 15 21 24 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc RSP: 0018:ffffc9000db5f560 EFLAGS: 00000246 RAX: ffffffff813ac8f9 RBX: ffffc9000db5f788 RCX: ffff88802bf0da00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffc9000db5f788 RBP: ffffc9000db5f698 R08: ffff88802bf0da00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc9000db5f648 R13: dffffc0000000000 R14: ffffc9000db5f788 R15: ffffffff8ecffd1a FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6221445000 CR3: 00000000274b2000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __read_once_word_nocheck+0x9/0x10 include/asm-generic/rwonce.h:66 deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline] unwind_next_frame+0x15f9/0x2970 arch/x86/kernel/unwind_orc.c:585 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1284 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293