INFO: task syz.2.24:6172 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.24 state:D stack:28440 pid:6172 tgid:6136 ppid:5820 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:994 [inline] open_last_lookups fs/namei.c:3894 [inline] path_openat+0x8d7/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 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: 0033:0x7f9fcfa1eec9 RSP: 002b:00007f9fcdc65038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f9fcfc76090 RCX: 00007f9fcfa1eec9 RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f9fcfaa1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9fcfc76128 R14: 00007f9fcfc76090 R15: 00007ffd897e1608 INFO: task syz.2.24:6173 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.24 state:D stack:29192 pid:6173 tgid:6136 ppid:5820 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1024 [inline] do_unlinkat+0x1c7/0x570 fs/namei.c:4724 __do_sys_unlink fs/namei.c:4783 [inline] __se_sys_unlink fs/namei.c:4781 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4781 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: 0033:0x7f9fcfa1eec9 RSP: 002b:00007f9fcdc44038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f9fcfc76180 RCX: 00007f9fcfa1eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000040 RBP: 00007f9fcfaa1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9fcfc76218 R14: 00007f9fcfc76180 R15: 00007ffd897e1608 INFO: task syz.2.24:6174 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.24 state:D stack:28616 pid:6174 tgid:6136 ppid:5820 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:979 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8e6/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 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: 0033:0x7f9fcfa1eec9 RSP: 002b:00007f9fcd821038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f9fcfc76270 RCX: 00007f9fcfa1eec9 RDX: 0000000000105042 RSI: 0000200000000180 RDI: ffffffffffffff9c RBP: 00007f9fcfaa1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000019a R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9fcfc76308 R14: 00007f9fcfc76270 R15: 00007ffd897e1608 INFO: task syz.2.24:6176 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.24 state:D stack:28264 pid:6176 tgid:6136 ppid:5820 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:979 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8e6/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 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: 0033:0x7f9fcfa1eec9 RSP: 002b:00007f9fcd3fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f9fcfc76360 RCX: 00007f9fcfa1eec9 RDX: 0000000000101042 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f9fcfaa1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000015 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9fcfc763f8 R14: 00007f9fcfc76360 R15: 00007ffd897e1608 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff888140462938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888140462938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000117bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000117bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880376b00d0 (&type->s_umount_key#64){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88805e1859a8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 1 lock held by khungtaskd/38: #0: ffffffff8d3aa400 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d3aa400 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d3aa400 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/43: 5 locks held by kworker/u8:3/58: 4 locks held by kworker/u8:8/3509: #0: ffff888019a94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888019a94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000dbcfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000dbcfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e65af60 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffff8880671297b8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x2f0 drivers/net/wireguard/device.c:249 2 locks held by dhcpcd/5478: #0: ffff888062006918 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90 net/netlink/af_netlink.c:2269 #1: ffffffff8e667e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e667e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6822 2 locks held by getty/5573: #0: ffff88823bf388a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/5938: 4 locks held by syz.2.24/6138: 1 lock held by syz.2.24/6172: #0: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline] #0: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: open_last_lookups fs/namei.c:3894 [inline] #0: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: path_openat+0x8d7/0x3840 fs/namei.c:4131 2 locks held by syz.2.24/6173: #0: ffff8880376b0480 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88805e185d78 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1024 [inline] #1: ffff88805e185d78 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: do_unlinkat+0x1c7/0x570 fs/namei.c:4724 2 locks held by syz.2.24/6174: #0: ffff8880376b0480 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 2 locks held by syz.2.24/6176: #0: ffff8880376b0480 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88805e185d78 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 1 lock held by syz-executor/7516: #0: ffffffff8e667e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e667e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8e667e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 3 locks held by syz-executor/7543: 3 locks held by syz.4.227/7832: 3 locks held by syz.1.228/7834: 1 lock held by syz.6.229/7843: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:158 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: 58 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:task_irq_context kernel/locking/lockdep.c:4682 [inline] RIP: 0010:__lock_acquire+0x2b9/0xd20 kernel/locking/lockdep.c:5174 Code: e0 ff ff 41 23 54 c7 20 09 ca 41 89 54 c7 20 4d 89 4c c7 08 49 89 5c c7 10 4c 8b 6c 24 68 4d 89 6c c7 18 65 8b 15 63 9c e5 0f <31> f6 85 d2 40 0f 95 c6 31 d2 83 bf 44 0b 00 00 00 0f 95 c2 c1 e2 RSP: 0018:ffffc9000124f510 EFLAGS: 00000006 RAX: 000000000000001e RBX: ffff8880b893fba8 RCX: 0000000000000039 RDX: 0000000000000000 RSI: 0000000000000039 RDI: ffff888019761e00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ab8372a R10: dffffc0000000000 R11: fffffbfff1d6bbc7 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff888019762960 FS: 0000000000000000(0000) GS:ffff888127120000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f30d2745000 CR3: 000000003db06000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x14a/0x3e0 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:44 [inline] ___slab_alloc+0x122a/0x1470 mm/slub.c:4677 __slab_alloc+0xc6/0x1f0 mm/slub.c:4746 __slab_alloc_node mm/slub.c:4822 [inline] slab_alloc_node mm/slub.c:5233 [inline] __do_kmalloc_node mm/slub.c:5602 [inline] __kmalloc_node_track_caller_noprof+0x2a8/0x7e0 mm/slub.c:5712 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:763 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x29f/0xbc0 drivers/net/netdevsim/dev.c:866 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245