INFO: task syz.5.179:7453 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-00105-g2942242dde89 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.179 state:D stack:28744 pid:7453 tgid:7437 ppid:6231 task_flags:0x400040 flags:0x00004004 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 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:869 [inline] open_last_lookups fs/namei.c:3813 [inline] path_openat+0x8da/0x3830 fs/namei.c:4052 do_filp_open+0x1fa/0x410 fs/namei.c:4082 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1530 [inline] __se_sys_creat fs/open.c:1524 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1524 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: 0033:0x7fcbcdd8e9a9 RSP: 002b:00007fcbcebe1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fcbcdfb6080 RCX: 00007fcbcdd8e9a9 RDX: 0000000000000000 RSI: 00000000000000ec RDI: 0000200000000580 RBP: 00007fcbcde10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fcbcdfb6080 R15: 00007ffd91cc29f8 INFO: task syz.5.179:7455 blocked for more than 144 seconds. Not tainted 6.16.0-rc7-syzkaller-00105-g2942242dde89 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.179 state:D stack:28776 pid:7455 tgid:7437 ppid:6231 task_flags:0x400040 flags:0x00004004 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 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:869 [inline] open_last_lookups fs/namei.c:3813 [inline] path_openat+0x8da/0x3830 fs/namei.c:4052 do_filp_open+0x1fa/0x410 fs/namei.c:4082 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1530 [inline] __se_sys_creat fs/open.c:1524 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1524 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: 0033:0x7fcbcdd8e9a9 RSP: 002b:00007fcbcebc0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fcbcdfb6160 RCX: 00007fcbcdd8e9a9 RDX: 0000000000000000 RSI: 0000000000000184 RDI: 0000200000000d80 RBP: 00007fcbcde10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fcbcdfb6160 R15: 00007ffd91cc29f8 INFO: task syz.5.179:7461 blocked for more than 144 seconds. Not tainted 6.16.0-rc7-syzkaller-00105-g2942242dde89 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.179 state:D stack:28904 pid:7461 tgid:7437 ppid:6231 task_flags:0x400040 flags:0x00004004 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 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1694 inode_lock_nested include/linux/fs.h:914 [inline] filename_create+0x1f9/0x470 fs/namei.c:4148 do_mkdirat+0xa0/0x590 fs/namei.c:4400 __do_sys_mkdirat fs/namei.c:4425 [inline] __se_sys_mkdirat fs/namei.c:4423 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4423 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: 0033:0x7fcbcdd8d217 RSP: 002b:00007fcbceb9ee68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fcbceb9eef0 RCX: 00007fcbcdd8d217 RDX: 00000000000001ff RSI: 0000200000000680 RDI: 00000000ffffff9c RBP: 0000200000000080 R08: 0000200000000140 R09: 0000000000000000 R10: 0000200000000080 R11: 0000000000000246 R12: 0000200000000680 R13: 00007fcbceb9eeb0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000117bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000117bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by kworker/u8:1/13: #0: ffff88801dab0948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801dab0948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000127bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000127bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff888026bb60e0 (&type->s_umount_key#106){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff888056b40b00 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102 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 5 locks held by kworker/u8:4/78: #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000216fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000216fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f4fd310 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662 #3: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12630 #4: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #4: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by dhcpcd/5503: #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1121 2 locks held by getty/5601: #0: ffff8880359720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036d42f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz.5.179/7438: 2 locks held by syz.5.179/7453: #0: ffff888026bb6428 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff888056b40eb0 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #1: ffff888056b40eb0 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: open_last_lookups fs/namei.c:3813 [inline] #1: ffff888056b40eb0 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4052 2 locks held by syz.5.179/7455: #0: ffff888026bb6428 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff888056b40eb0 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #1: ffff888056b40eb0 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: open_last_lookups fs/namei.c:3813 [inline] #1: ffff888056b40eb0 (&type->i_mutex_dir_key#21){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4052 2 locks held by syz.5.179/7461: #0: ffff888026bb6428 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff888056b40eb0 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline] #1: ffff888056b40eb0 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4148 2 locks held by syz.1.233/8057: #0: ffff888026bb60e0 (&type->s_umount_key#106){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888026bb60e0 (&type->s_umount_key#106){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff888024f2c7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888024f2c7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 3 locks held by syz-executor/8269: #0: ffff888031d5c0e0 (&type->s_umount_key#66){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888031d5c0e0 (&type->s_umount_key#66){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888031d5c0e0 (&type->s_umount_key#66){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff88804c380278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:676 #2: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #2: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz-executor/9280: #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5026 1 lock held by syz-executor/9327: #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-00105-g2942242dde89 #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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3006 Comm: kworker/u8:9 Not tainted 6.16.0-rc7-syzkaller-00105-g2942242dde89 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:check_preemption_disabled+0x17/0x120 lib/smp_processor_id.c:14 Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 ee ed 35 07 48 89 44 24 08 <65> 8b 05 f6 ed 35 07 65 8b 0d eb ed 35 07 f7 c1 ff ff ff 7f 74 23 RSP: 0018:ffffc9000b986f00 EFLAGS: 00000086 RAX: d9b7f048b9911a00 RBX: 0000000000000000 RCX: d9b7f048b9911a00 RDX: 0000000000000000 RSI: ffffffff8d996891 RDI: ffffffff8be1ba80 RBP: ffffffff8172aae5 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc9000b9870f8 R11: ffffffff81acfd40 R12: 0000000000000002 R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd15b36da8 CR3: 000000002921c000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:468 [inline] lock_acquire+0xe7/0x360 kernel/locking/lockdep.c:5870 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 save_stack+0xf7/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859 __slab_alloc mm/slub.c:3949 [inline] __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] kmem_cache_alloc_node_noprof+0x280/0x3c0 mm/slub.c:4249 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1336 [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+0x29a/0xb80 drivers/net/netdevsim/dev.c:851 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