syzbot

INFO: task syz.8.731:11324 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc7-syzkaller-00175-g0f8c0258bf04 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.731       state:D stack:22808 pid:11324 tgid:11320 ppid:7917   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:229 [inline]
 __down_common+0x319/0x6a0 kernel/locking/semaphore.c:250
 down+0x80/0xd0 kernel/locking/semaphore.c:64
 xfs_buf_lock+0x15d/0x4d0 fs/xfs/xfs_buf.c:996
 xfs_buf_item_unpin+0x1ce/0x6c0 fs/xfs/xfs_buf_item.c:468
 xlog_cil_ail_insert fs/xfs/xfs_log_cil.c:-1 [inline]
 xlog_cil_committed+0x7c3/0xe70 fs/xfs/xfs_log_cil.c:904
 xlog_cil_process_committed+0x15c/0x1b0 fs/xfs/xfs_log_cil.c:934
 xlog_state_shutdown_callbacks+0x269/0x360 fs/xfs/xfs_log.c:488
 xlog_force_shutdown+0x332/0x400 fs/xfs/xfs_log.c:3540
 xfs_do_force_shutdown+0x283/0x640 fs/xfs/xfs_fsops.c:517
 xfs_fs_goingdown+0x71/0x150 fs/xfs/xfs_fsops.c:-1
 xfs_file_ioctl+0x113e/0x1870 fs/xfs/xfs_ioctl.c:1378
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe70dd8e969
RSP: 002b:00007fe70ebda038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe70dfb5fa0 RCX: 00007fe70dd8e969
RDX: 0000200000000340 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007fe70de10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe70dfb5fa0 R15: 00007ffc54ed0088
 </TASK>
INFO: task syz.8.731:11373 blocked for more than 144 seconds.
      Not tainted 6.15.0-rc7-syzkaller-00175-g0f8c0258bf04 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.731       state:D stack:26968 pid:11373 tgid:11320 ppid:7917   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 xlog_wait fs/xfs/xfs_log_priv.h:588 [inline]
 xlog_wait_on_iclog+0x4ac/0x6f0 fs/xfs/xfs_log.c:841
 xlog_force_lsn+0x4d7/0x960 fs/xfs/xfs_log.c:3065
 xfs_log_force_seq+0x1c9/0x440 fs/xfs/xfs_log.c:3102
 __xfs_trans_commit+0x7d2/0xbd0 fs/xfs/xfs_trans.c:905
 xfs_trans_commit+0x13e/0x1c0 fs/xfs/xfs_trans.c:954
 xfs_sync_sb_buf+0x134/0x230 fs/xfs/libxfs/xfs_sb.c:1474
 xfs_ioc_setlabel fs/xfs/xfs_ioctl.c:1046 [inline]
 xfs_file_ioctl+0x1536/0x1870 fs/xfs/xfs_ioctl.c:1203
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe70dd8e969
RSP: 002b:00007fe70ebb9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe70dfb6080 RCX: 00007fe70dd8e969
RDX: 0000200000000080 RSI: 0000000041009432 RDI: 0000000000000004
RBP: 00007fe70de10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fe70dfb6080 R15: 00007ffc54ed0088
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
5 locks held by kworker/u8:2/36:
 #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc90000ad7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000ad7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffffffff8f2dbdd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608
 #3: ffff88805df894e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x2f0 drivers/net/wireguard/device.c:249
 #4: ffffffff8df43880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774
4 locks held by kworker/u8:8/1166:
 #0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
 #1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
 #2: ffff888024e0b8e0 (&lo->lo_work_lock){..-.}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
 #2: ffff888024e0b8e0 (&lo->lo_work_lock){..-.}-{3:3}, at: loop_process_work+0xb12/0xf30 drivers/block/loop.c:1924
 #3: ffffffff999ac2d0 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_assert_init+0xb4/0x380 lib/debugobjects.c:1007
2 locks held by getty/5579:
 #0: ffff8880358620a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/9580:
 #0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
1 lock held by syz.8.731/11373:
 #0: ffff888053472420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:600
7 locks held by syz-executor/13586:
 #0: ffff888035bd6420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
 #0: ffff888035bd6420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680
 #1: ffff88807bdba488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325
 #2: ffff8880275b54b8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326
 #3: ffffffff8eb88668 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216
 #4: ffff88802d6a10e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
 #4: ffff88802d6a10e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline]
 #4: ffff88802d6a10e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292
 #5: ffff88802d6a5250 (&devlink->lock_key#9){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675
 #6: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: unregister_nexthop_notifier+0x17/0x40 net/ipv4/nexthop.c:3946
2 locks held by syz-executor/13640:
 #0: ffffffff8ea822e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ea822e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8ea822e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f2e8908 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064
2 locks held by syz.9.1002/14129:
1 lock held by rm/14130:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00175-g0f8c0258bf04 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 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:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:437
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13586 Comm: syz-executor Not tainted 6.15.0-rc7-syzkaller-00175-g0f8c0258bf04 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:check_preemption_disabled+0x59/0x120 lib/smp_processor_id.c:19
Code: 8b 0d 2b ee 22 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 51 b5 02 00 cc 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 74 c8 65 4c 8b 3c 25 08 a0 72 92 41
RSP: 0018:ffffc90003e97250 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000206 RCX: 0000000080000000
RDX: ffffc90003e97401 RSI: ffffffff8d74e3a8 RDI: ffffffff8bc12300
RBP: dffffc0000000000 R08: ffffc90003e97ef0 R09: 0000000000000000
R10: ffffc90003e97418 R11: fffff520007d2e85 R12: ffffc90003e97f00
R13: ffffffff8171ca05 R14: ffffffff8df3dee0 R15: ffff88801c76bc00
FS:  0000555566ae4500(0000) GS:ffff8881261f6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa1e0f63000 CR3: 000000007a816000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:467 [inline]
 lock_release+0xbc/0x3e0 kernel/locking/lockdep.c:5886
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x193/0x440 mm/slub.c:4841
 nsim_fib4_rt_free drivers/net/netdevsim/fib.c:1058 [inline]
 nsim_fib_rt_free+0x305/0x660 drivers/net/netdevsim/fib.c:1079
 rhashtable_free_one lib/rhashtable.c:1117 [inline]
 rhashtable_free_and_destroy+0x5b6/0x940 lib/rhashtable.c:1168
 nsim_fib_destroy+0xb4/0x180 drivers/net/netdevsim/fib.c:1660
 nsim_dev_reload_destroy+0x2e3/0x490 drivers/net/netdevsim/dev.c:1665
 nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1676
 device_remove drivers/base/dd.c:567 [inline]
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x46c/0x7c0 drivers/base/dd.c:1295
 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579
 device_del+0x511/0x8e0 drivers/base/core.c:3881
 device_unregister+0x20/0xc0 drivers/base/core.c:3922
 nsim_bus_dev_del drivers/net/netdevsim/bus.c:462 [inline]
 del_device_store+0x2aa/0x360 drivers/net/netdevsim/bus.c:226
 kernfs_fop_write_iter+0x378/0x4f0 fs/kernfs/file.c:334
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x54b/0xa90 fs/read_write.c:684
 ksys_write+0x145/0x250 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a6eb8d41f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007ffc45cb1560 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f0a6eb8d41f
RDX: 0000000000000001 RSI: 00007ffc45cb15b0 RDI: 0000000000000005
RBP: 00007f0a6ec11d05 R08: 0000000000000000 R09: 00007ffc45cb13b7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007ffc45cb15b0 R14: 00007f0a6f8e4620 R15: 0000000000000003
 </TASK>