syzbot

INFO: task syz.3.155:7404 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00110-gff7afaeca1a1 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.155       state:D stack:24800 pid:7404  tgid:7323  ppid:5839   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x17fa/0x4bd0 kernel/sched/core.c:6690
 __schedule_loop kernel/sched/core.c:6767 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6782
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839
 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578
 inode_lock include/linux/fs.h:815 [inline]
 do_truncate fs/open.c:63 [inline]
 do_ftruncate+0x44e/0x580 fs/open.c:181
 do_sys_ftruncate fs/open.c:199 [inline]
 __do_sys_ftruncate fs/open.c:207 [inline]
 __se_sys_ftruncate fs/open.c:205 [inline]
 __x64_sys_ftruncate+0x95/0xf0 fs/open.c:205
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff5b977e719
RSP: 002b:00007ff5b7bf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007ff5b9936058 RCX: 00007ff5b977e719
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000005
RBP: 00007ff5b97f139e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff5b9936058 R15: 00007ffd694cc538
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
2 locks held by kworker/u8:2/35:
3 locks held by kworker/u8:5/795:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900036dfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900036dfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
7 locks held by kworker/u8:6/1158:
 #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900040c7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900040c7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcb4890 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580
 #3: ffff8880585b50e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #3: ffff8880585b50e8 (&dev->mutex){....}-{3:3}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
 #3: ffff8880585b50e8 (&dev->mutex){....}-{3:3}, at: devlink_pernet_pre_exit+0x13b/0x440 net/devlink/core.c:506
 #4: ffff888063c04250 (&devlink->lock_key#15){+.+.}-{3:3}, at: devl_lock net/devlink/core.c:276 [inline]
 #4: ffff888063c04250 (&devlink->lock_key#15){+.+.}-{3:3}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
 #4: ffff888063c04250 (&devlink->lock_key#15){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0x14d/0x440 net/devlink/core.c:506
 #5: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773
 #6: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline]
 #6: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976
2 locks held by dhcpcd/5497:
 #0: ffffffff8fca5e88 (vlan_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x661/0x8e0 net/socket.c:1308
 #1: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: vlan_ioctl_handler+0x112/0x9d0 net/8021q/vlan.c:553
2 locks held by getty/5583:
 #0: ffff88803124d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:4/5878:
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900045c7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900045c7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
5 locks held by syz.3.155/7325:
 #0: ffff88803281a420 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
 #1: ffff88805dbb88c8 (&sb->s_type->i_mutex_key#31){++++}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #1: ffff88805dbb88c8 (&sb->s_type->i_mutex_key#31){++++}-{3:3}, at: do_truncate+0x20c/0x310 fs/open.c:63
 #2: ffff888071480a38 (&c->snapshot_create_lock){.+.+}-{3:3}, at: bch2_truncate+0x166/0x2d0 fs/bcachefs/io_misc.c:292
 #3: ffff888071484398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:151 [inline]
 #3: ffff888071484398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:250 [inline]
 #3: ffff888071484398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7de/0xd20 fs/bcachefs/btree_iter.c:3228
 #4: ffff8880714a66d0 (&c->gc_lock){++++}-{3:3}, at: bch2_btree_update_start+0x682/0x14e0 fs/bcachefs/btree_update_interior.c:1202
2 locks held by syz.3.155/7404:
 #0: ffff88803281a420 (sb_writers#27){.+.+}-{0:0}, at: do_ftruncate+0x28b/0x580 fs/open.c:178
 #1: ffff88805dbb88c8 (&sb->s_type->i_mutex_key#31){++++}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #1: ffff88805dbb88c8 (&sb->s_type->i_mutex_key#31){++++}-{3:3}, at: do_truncate fs/open.c:63 [inline]
 #1: ffff88805dbb88c8 (&sb->s_type->i_mutex_key#31){++++}-{3:3}, at: do_ftruncate+0x44e/0x580 fs/open.c:181
1 lock held by syz-executor/8334:
 #0: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline]
 #0: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976
7 locks held by syz-executor/9848:
 #0: ffff8880350e0420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff8880350e0420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff88807e3f7c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff888143fd4b48 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f55f208 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166
 #4: ffff8880647780e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #4: ffff8880647780e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005
 #5: ffff88802646f250 (&devlink->lock_key#16){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1537
 #6: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: fib_seq_sum+0x31/0x290 net/core/fib_notifier.c:46
1 lock held by syz-executor/10118:
 #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6672
1 lock held by syz-executor/10121:
 #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6672

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00110-gff7afaeca1a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.12.0-rc6-syzkaller-00110-gff7afaeca1a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:105 [inline]
RIP: 0010:do_raw_spin_unlock+0xe4/0x8b0 kernel/locking/spinlock_debug.c:141
Code: 03 84 c0 0f 85 f0 03 00 00 41 8b 06 65 8b 0d 5f 22 92 7e 39 c8 0f 85 cb 02 00 00 48 bd 00 00 00 00 00 fc ff df 41 80 3c 2c 00 <74> 08 4c 89 ef e8 12 c8 89 00 49 c7 45 00 ff ff ff ff 0f b6 04 2b
RSP: 0018:ffffc900015d7a48 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff1100fa33221 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807d199100
RBP: dffffc0000000000 R08: ffff88807d199103 R09: 1ffff1100fa33220
R10: dffffc0000000000 R11: ffffed100fa33221 R12: 1ffff1100fa33222
R13: ffff88807d199110 R14: ffff88807d199108 R15: ffff88807d199100
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 0000000058f2c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:166 [inline]
 _raw_spin_unlock_bh+0x23/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_nc_purge_paths+0x312/0x3b0 net/batman-adv/network-coding.c:471
 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>