INFO: task syz.5.150:6957 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.150 state:D stack:28136 pid:6957 tgid:6950 ppid:6132 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] lookup_slow+0x46/0x70 fs/namei.c:1832 walk_component+0x2d2/0x400 fs/namei.c:2151 lookup_last fs/namei.c:2652 [inline] path_lookupat+0x163/0x430 fs/namei.c:2676 filename_lookup+0x212/0x570 fs/namei.c:2705 user_path_at+0x3a/0x60 fs/namei.c:3215 do_mount fs/namespace.c:4075 [inline] __do_sys_mount fs/namespace.c:4278 [inline] __se_sys_mount+0x2d3/0x410 fs/namespace.c:4255 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: 0033:0x7f3034aceec9 RSP: 002b:00007f3032cf4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f3034d26180 RCX: 00007f3034aceec9 RDX: 0000200000000180 RSI: 0000200000000140 RDI: 00002000000000c0 RBP: 00007f3034b51f91 R08: 0000200000000240 R09: 0000000000000000 R10: 0000000000000010 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3034d26218 R14: 00007f3034d26180 R15: 00007ffc9503bdd8 INFO: task syz.5.150:6958 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.150 state:D stack:28680 pid:6958 tgid:6950 ppid:6132 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:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 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: 0033:0x7f3034aceec9 RSP: 002b:00007f30328d1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3034d26270 RCX: 00007f3034aceec9 RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f3034b51f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3034d26308 R14: 00007f3034d26270 R15: 00007ffc9503bdd8 INFO: task syz.5.150:6959 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.150 state:D stack:27048 pid:6959 tgid:6950 ppid:6132 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:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_creat fs/open.c:1528 [inline] __se_sys_creat fs/open.c:1522 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1522 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: 0033:0x7f3034aceec9 RSP: 002b:00007f30324ae038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f3034d26360 RCX: 00007f3034aceec9 RDX: 0000000000000000 RSI: 0000000000000182 RDI: 0000200000000100 RBP: 00007f3034b51f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3034d263f8 R14: 00007f3034d26360 R15: 00007ffc9503bdd8 Showing all locks held in the system: 5 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/39: #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/57: #0: ffff88814d026138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88814d026138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000123fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000123fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 4 locks held by kworker/u8:4/67: #0: ffff888019a94138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888019a94138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000152fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000152fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e652520 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12807 4 locks held by kworker/u8:10/3612: #0: ffff88801ee92138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801ee92138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000db6fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000db6fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88805ebb00d0 (&type->s_umount_key#62){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff888060948ba8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102 1 lock held by dhcpcd/5471: #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by getty/5568: #0: ffff88823bf780a0 (&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 4 locks held by syz.5.150/6951: 1 lock held by syz.5.150/6957: #0: ffff888060948f78 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline] #0: ffff888060948f78 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 2 locks held by syz.5.150/6958: #0: ffff88805ebb0488 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500 #1: ffff888060948f78 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff888060948f78 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff888060948f78 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 2 locks held by syz.5.150/6959: #0: ffff88805ebb0488 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500 #1: ffff888060948f78 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline] #1: ffff888060948f78 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff888060948f78 (&type->i_mutex_dir_key#10){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 1 lock held by syz-executor/7393: #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 7 locks held by syz-executor/7433: #0: ffff88803393c488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3103 [inline] #0: ffff88803393c488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805ba29c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888144f421e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888144f421e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ded8698 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 #4: ffff88803cd900d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff88803cd900d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff88803cd900d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 #5: ffff88803cd92300 (&devlink->lock_key#18){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721 #6: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 4 locks held by syz-executor/7436: #0: ffff88803393c488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3103 [inline] #0: ffff88803393c488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805c152078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888144f420f8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888144f420f8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ded8698 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 4 locks held by syz-executor/7441: #0: ffff88803393c488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3103 [inline] #0: ffff88803393c488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff888035a87c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888144f420f8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888144f420f8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ded8698 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 4 locks held by syz-executor/7444: #0: ffff88803393c488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3103 [inline] #0: ffff88803393c488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff888035c08078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888144f420f8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888144f420f8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8ded8698 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 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:148 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: 157 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:__lock_acquire+0x2d0/0xd20 kernel/locking/lockdep.c:5174 Code: c7 10 4c 8b 6c 24 68 4d 89 6c c7 18 65 8b 15 63 cb e3 0f 31 f6 85 d2 40 0f 95 c6 31 d2 83 bf 44 0b 00 00 00 0f 95 c2 c1 e2 0d e6 0e 09 d6 8b 54 24 1c c1 e2 0f 0f b7 d2 09 f2 41 83 e4 03 41 RSP: 0018:ffffc90003a37750 EFLAGS: 00000046 RAX: 000000000000000f RBX: ffffffff8d3aa300 RCX: 000000000000000b RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888020370000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8a7a615d R10: dffffc0000000000 R11: ffffed1007456817 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: ffff888020370b60 FS: 0000000000000000(0000) GS:ffff88812713b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005567d0fe1000 CR3: 000000000d1a6000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:761 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline] batadv_iv_ogm_schedule+0x46e/0xf00 net/batman-adv/bat_iv_ogm.c:873 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1709 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:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245