INFO: task syz.6.434:10334 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.434 state:D stack:28288 pid:10334 tgid:10329 ppid:9470 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] ntfs_file_write_iter+0xe6/0x870 fs/ntfs3/file.c:1284 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x629/0xba0 fs/read_write.c:686 ksys_write+0x156/0x270 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff1ebddacb9 RSP: 002b:00007ff1ea015028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff1ec056090 RCX: 00007ff1ebddacb9 RDX: 0000000000000009 RSI: 0000200000000140 RDI: 0000000000000005 RBP: 00007ff1ebe48bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff1ec056128 R14: 00007ff1ec056090 R15: 00007ffc834689a8 INFO: task syz.6.434:10341 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.434 state:D stack:27520 pid:10341 tgid:10329 ppid:9470 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1027 [inline] process_measurement+0x458/0x1cc0 security/integrity/ima/ima_main.c:281 ima_file_check+0xdf/0x130 security/integrity/ima/ima_main.c:663 security_file_post_open+0xb3/0x260 security/security.c:2652 do_open fs/namei.c:4639 [inline] path_openat+0x350e/0x3e70 fs/namei.c:4796 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff1ebddacb9 RSP: 002b:00007ff1e9ff4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ff1ec056180 RCX: 00007ff1ebddacb9 RDX: 000000000014b302 RSI: 0000200000000180 RDI: ffffffffffffff9c RBP: 00007ff1ebe48bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000008c R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff1ec056218 R14: 00007ff1ec056180 R15: 00007ffc834689a8 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90000127bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000127bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by rcuc/1/28: 1 lock held by khungtaskd/38: #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:12/1304: #0: ffff88801aa94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801aa94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000558fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000558fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8ed295e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: wg_destruct+0x25/0x310 drivers/net/wireguard/device.c:246 1 lock held by udevd/5170: 2 locks held by dhcpcd/5465: #0: ffff88805ce7a928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267 #1: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 2 locks held by getty/5560: #0: ffff8881447ba0a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by syz-executor/9181: 2 locks held by syz.6.434/10332: 3 locks held by syz.6.434/10334: #0: ffff88803acc3928 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1255 #1: ffff88802077c480 (sb_writers#20){++++}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #1: ffff88802077c480 (sb_writers#20){++++}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682 #2: ffff888058b3d838 (&sb->s_type->i_mutex_key#35){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #2: ffff888058b3d838 (&sb->s_type->i_mutex_key#35){+.+.}-{4:4}, at: ntfs_file_write_iter+0xe6/0x870 fs/ntfs3/file.c:1284 2 locks held by syz.6.434/10341: #0: ffff88802077c480 (sb_writers#20){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888058b3d838 (&sb->s_type->i_mutex_key#35){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff888058b3d838 (&sb->s_type->i_mutex_key#35){+.+.}-{4:4}, at: process_measurement+0x458/0x1cc0 security/integrity/ima/ima_main.c:281 8 locks held by syz-executor/10765: #0: ffff888034ff0480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888034ff0480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682 #1: ffff88803920a878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff88814239a0f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814239a0f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e5a8ef8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff888027b140d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff888027b140d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline] #4: ffff888027b140d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1302 #5: ffff88803775a300 (&devlink->lock_key#33){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1778 #6: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1175 #7: ffff88813fe34238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x130 fs/kernfs/dir.c:1717 4 locks held by syz-executor/10919: #0: ffff888034ff0480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888034ff0480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682 #1: ffff888059211c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff88814239a008 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814239a008 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e5a8ef8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 4 locks held by syz-executor/11048: #0: ffff888034ff0480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888034ff0480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682 #1: ffff8880571d8478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff88814239a0f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814239a0f8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e5a8ef8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 1 lock held by syz-executor/11082: #0: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz-executor/11122: #0: ffffffff8e497548 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e497548 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e497548 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by udevd/11174: 2 locks held by syz-executor/11181: #0: ffffffff8ed295e0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cb/0x570 net/core/net_namespace.c:577 #1: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x88/0x290 net/ipv4/nexthop.c:3971 ============================================= 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 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 68 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:check_preemption_disabled+0x3/0xe0 lib/smp_processor_id.c:13 Code: 65 8b 48 c7 c6 e0 e6 65 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 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 65 8b 05 b7 36 12 07 65 8b 0d ac 36 12 07 f7 c1 ff ff ff RSP: 0018:ffffc9000153f868 EFLAGS: 00000046 RAX: e3154352c789c0d9 RBX: 0000000000000002 RCX: 0000000080000001 RDX: 0000000000000004 RSI: ffffffff8d396abd RDI: ffffffff8b65e700 RBP: ffff88801ce866f0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520002a7f0c R12: 0000000000000004 R13: 0000000000000004 R14: ffff888069849198 R15: ffff88801ce85ac0 FS: 0000000000000000(0000) GS:ffff8881268fc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd68b34cc0 CR3: 0000000030a60000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] lock_release+0x259/0x3a0 kernel/locking/lockdep.c:5891 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:194 unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline] rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1454 spin_unlock_bh include/linux/spinlock_rt.h:110 [inline] __batadv_dat_purge+0x335/0x400 net/batman-adv/distributed-arp-table.c:185 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246