INFO: task syz.9.1169:13133 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1169      state:D stack:23688 pid:13133 tgid:13131 ppid:11550  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x1681/0x54c0 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1659 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1736 [inline]
 __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1776
 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
 __down_read kernel/locking/rwsem.c:1496 [inline]
 down_read+0x132/0x200 kernel/locking/rwsem.c:1570
 filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline]
 do_page_cache_ra mm/readahead.c:333 [inline]
 page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538
 filemap_get_pages+0x47c/0x1e70 mm/filemap.c:2696
 filemap_splice_read+0x5d3/0xd20 mm/filemap.c:3085
 do_splice_read fs/splice.c:980 [inline]
 splice_direct_to_actor+0x483/0xc80 fs/splice.c:1084
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x19b/0x2a0 fs/splice.c:1228
 do_sendfile+0x547/0x7e0 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f59ade1c819
RSP: 002b:00007f59ac076028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f59ae095fa0 RCX: 00007f59ade1c819
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007f59adeb2c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f59ae096038 R14: 00007f59ae095fa0 R15: 00007ffdb07a5eb8
 </TASK>

Showing all locks held in the system:
8 locks held by ktimers/0/16:
1 lock held by khungtaskd/38:
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:2/40:
3 locks held by kworker/u8:16/4483:
 #0: ffff888032bbc138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
 #0: ffff888032bbc138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: ffffc9001046fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
 #1: ffffc9001046fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206
2 locks held by dhcpcd/5479:
 #0: ffff8880379ec928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
 #1: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6862
2 locks held by getty/5570:
 #0: ffff8880321f50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cbb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
7 locks held by kworker/u8:6/10149:
 #0: ffff88801b2a8938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
 #0: ffff88801b2a8938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: ffffc90005857c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
 #1: ffffc90005857c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: ffffffff8f35d120 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
 #3: ffff888067d00160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #3: ffff888067d00160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
 #3: ffff888067d00160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:555
 #4: ffff88803e60c310 (&devlink->lock_key#33){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
 #4: ffff88803e60c310 (&devlink->lock_key#33){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
 #4: ffff88803e60c310 (&devlink->lock_key#33){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:555
 #5: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x13a/0x830 drivers/net/netdevsim/netdev.c:1185
 #6: ffff888055d40f40 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2801 [inline]
 #6: ffff888055d40f40 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x588/0x22b0 net/core/dev.c:12424
2 locks held by syz.3.1128/12793:
3 locks held by kworker/u8:10/12912:
1 lock held by syz.9.1169/13133:
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline]
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538
1 lock held by syz.0.1208/13443:
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline]
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538
1 lock held by syz.5.1233/13585:
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline]
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
 #0: ffff8880264de7d8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538
1 lock held by syz-executor/13726:
 #0: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107
1 lock held by syz-executor/13733:
 #0: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107
7 locks held by syz-executor/13913:
 #0: ffff888034456480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline]
 #0: ffff888034456480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
 #1: ffff888033a77478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
 #2: ffff888028728008 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888028728008 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
 #3: ffffffff8ebd0c38 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
 #4: ffff88803cee0160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #4: ffff88803cee0160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
 #4: ffff88803cee0160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372
 #5: ffff888036884310 (&devlink->lock_key#32){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799
 #6: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x13a/0x830 drivers/net/netdevsim/netdev.c:1185
2 locks held by syz-executor/14031:
 #0: ffffffff8eabe0c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eabe0c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8eabe0c8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107
2 locks held by syz-executor/14058:
 #0: ffffffff8eabe0c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eabe0c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8eabe0c8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f36ba38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107

=============================================

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 03/18/2026
Call Trace:
 <TASK>
 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:162 [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:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12912 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:hlock_class kernel/locking/lockdep.c:246 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4879 [inline]
RIP: 0010:__lock_acquire+0x526/0x2cf0 kernel/locking/lockdep.c:5187
Code: 83 c3 28 41 89 c4 49 39 cf 0f 8d c7 00 00 00 49 83 ff 31 0f 83 83 00 00 00 8b 03 25 ff 1f 00 00 48 0f a3 05 6c 9f d9 11 73 10 <48> 69 c0 c8 00 00 00 48 8d 88 30 13 1b 93 eb 32 83 3d 73 2f dd 17
RSP: 0018:ffffc90003c07830 EFLAGS: 00000007
RAX: 00000000000000ed RBX: ffff88803a142b28 RCX: 0000000000000003
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88803a142b30 R08: ffffffff8187ddac R09: ffffffff8dfc80c0
R10: dffffc0000000000 R11: fffffbfff1f179df R12: 00000000ffffff05
R13: ffff88803a142b30 R14: ffff88803a141ec0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8881260fb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563f15e5c030 CR3: 0000000027334000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 __local_bh_disable_ip+0x205/0x420 kernel/softirq.c:174
 local_bh_disable include/linux/bottom_half.h:20 [inline]
 spin_lock_bh include/linux/spinlock_rt.h:89 [inline]
 __batadv_dat_purge+0x124/0x400 net/batman-adv/distributed-arp-table.c:173
 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>