INFO: task syz.0.253:7959 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.253 state:D stack:22088 pid:7959 tgid:7958 ppid:5800 task_flags:0x400140 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:1025 [inline] filename_create+0x1f8/0x3c0 fs/namei.c:4226 do_mkdirat+0xa0/0x590 fs/namei.c:4478 __do_sys_mkdir fs/namei.c:4508 [inline] __se_sys_mkdir fs/namei.c:4506 [inline] __x64_sys_mkdir+0x6c/0x80 fs/namei.c:4506 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f549fdaefc9 RSP: 002b:00007f549e00e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007f54a0005fa0 RCX: 00007f549fdaefc9 RDX: 0000000000000000 RSI: 0000000000000184 RDI: 0000200000000140 RBP: 00007f549fe31f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f54a0006038 R14: 00007f54a0005fa0 R15: 00007fff0b7cbc68 INFO: task syz.0.253:7962 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.253 state:D stack:29224 pid:7962 tgid:7958 ppid:5800 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:1025 [inline] do_unlinkat+0x1c7/0x570 fs/namei.c:4724 __do_sys_unlinkat fs/namei.c:4778 [inline] __se_sys_unlinkat fs/namei.c:4771 [inline] __x64_sys_unlinkat+0xd3/0xf0 fs/namei.c:4771 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f549fdaefc9 RSP: 002b:00007f549dba9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 00007f54a0006270 RCX: 00007f549fdaefc9 RDX: 0000000000000000 RSI: 0000200000000380 RDI: ffffffffffffff9c RBP: 00007f549fe31f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f54a0006308 R14: 00007f54a0006270 R15: 00007fff0b7cbc68 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d5aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:3/57: #0: ffff88814047a938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88814047a938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000123fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000123fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88803b51c0d0 (&type->s_umount_key#67){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88805a8fe368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 7 locks held by kworker/u8:5/1145: 3 locks held by kworker/u8:6/1165: #0: ffff88802fb63938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88802fb63938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000505fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000505fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 6 locks held by kworker/u8:7/1175: 3 locks held by kworker/u8:9/3961: #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000e7f7ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000e7f7ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by dhcpcd/5461: #0: ffffffff8e847298 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5f1/0x790 net/socket.c:1337 #1: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:577 2 locks held by getty/5554: #0: ffff88823bf300a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 2 locks held by kworker/u8:13/6337: 2 locks held by syz.0.253/7959: #0: ffff88803b51c480 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88805a8fe738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff88805a8fe738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4226 4 locks held by syz.0.253/7960: 2 locks held by syz.0.253/7962: #0: ffff88803b51c480 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88805a8fe738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff88805a8fe738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: do_unlinkat+0x1c7/0x570 fs/namei.c:4724 1 lock held by syz-executor/8326: #0: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 3 locks held by kworker/0:8/8371: #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003a6fba0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003a6fba0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 7 locks held by syz-executor/8372: #0: ffff888034424480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline] #0: ffff888034424480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805b6afc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888026736968 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888026736968 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e0f3bf8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 #4: ffff88803b1e80d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff88803b1e80d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #5: ffff88803b1ef300 (&devlink->lock_key#26){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582 #6: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 2 locks held by syz-executor/8401: #0: ffffffff8dfc6de0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dfc6de0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8dfc6de0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz-executor/8423: #0: ffffffff8e855f20 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576 #1: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11407 2 locks held by syz-executor/8430: #0: ffffffff8e855f20 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576 #1: ffffffff8e862e38 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x80/0x210 net/ipv4/nexthop.c:3971 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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+0x4bc/0x870 arch/x86/kernel/process.c:158 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: 6337 Comm: kworker/u8:13 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:kasan_byte_accessible+0x16/0x30 mm/kasan/generic.c:212 Code: 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df 0f b6 04 07 <3c> 08 0f 92 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e 0f 1f 84 00 RSP: 0018:ffffc90004a777c0 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffffffff8ac28a08 RCX: 7b88ddacbc333200 RDX: 0000000000000000 RSI: ffffffff8ac28a08 RDI: 1ffff1100cc158cb RBP: ffffffff8a90e683 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1dac50f R12: 0000000000000000 R13: ffff8880660ac658 R14: ffff8880660ac658 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888126dfc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005563f7fee880 CR3: 000000000d3a6000 CR4: 00000000003526f0 Call Trace: __kasan_check_byte+0x12/0x40 mm/kasan/common.c:579 kasan_check_byte include/linux/kasan.h:401 [inline] lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842 rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56 spin_lock_bh include/linux/spinlock_rt.h:88 [inline] batadv_tt_local_purge+0x143/0x380 net/batman-adv/translation-table.c:1313 batadv_tt_purge+0x35/0xa10 net/batman-adv/translation-table.c:3509 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+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245