syzbot

INFO: task syz.1.20:6006 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.20        state:D stack:23520 pid:6006  tgid:6002  ppid:5825   flags:0x00004004
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_lock_mount+0x112/0x3a0 fs/namespace.c:2607
 lock_mount fs/namespace.c:2649 [inline]
 do_loopback+0x2be/0x520 fs/namespace.c:2772
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 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: 0033:0x7f43a477e719
RSP: 002b:00007f43a55e4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f43a4936058 RCX: 00007f43a477e719
RDX: 0000000000000000 RSI: 0000000020000200 RDI: 00000000200002c0
RBP: 00007f43a47f139e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000101091 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f43a4936058 R15: 00007ffcd84dd7c8
 </TASK>
INFO: task syz.1.20:6024 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.20        state:D stack:27424 pid:6024  tgid:6002  ppid:5825   flags:0x00004004
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_lock_mount+0x112/0x3a0 fs/namespace.c:2607
 do_move_mount+0x25/0x800 fs/namespace.c:3282
 __do_sys_move_mount fs/namespace.c:4278 [inline]
 __se_sys_move_mount+0x26b/0xd20 fs/namespace.c:4230
 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: 0033:0x7f43a477e719
RSP: 002b:00007f43a55c3038 EFLAGS: 00000246 ORIG_RAX: 00000000000001ad
RAX: ffffffffffffffda RBX: 00007f43a4936130 RCX: 00007f43a477e719
RDX: ffffffffffffff9c RSI: 0000000020000140 RDI: 0000000000000006
RBP: 00007f43a47f139e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000300 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f43a4936130 R15: 00007ffcd84dd7c8
 </TASK>
INFO: task syz.1.20:6025 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.20        state:D stack:27424 pid:6025  tgid:6002  ppid:5825   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_read_slowpath kernel/locking/rwsem.c:1084 [inline]
 __down_read_common kernel/locking/rwsem.c:1248 [inline]
 __down_read kernel/locking/rwsem.c:1261 [inline]
 down_read+0x705/0xa40 kernel/locking/rwsem.c:1526
 inode_lock_shared include/linux/fs.h:825 [inline]
 lookup_slow+0x45/0x70 fs/namei.c:1748
 walk_component fs/namei.c:2053 [inline]
 link_path_walk+0x99b/0xea0 fs/namei.c:2418
 path_lookupat+0xa9/0x450 fs/namei.c:2579
 filename_lookup+0x256/0x610 fs/namei.c:2609
 user_path_at+0x3a/0x60 fs/namei.c:3016
 __do_sys_pivot_root fs/namespace.c:4354 [inline]
 __se_sys_pivot_root+0x1da/0x1650 fs/namespace.c:4338
 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: 0033:0x7f43a477e719
RSP: 002b:00007f43a55a2038 EFLAGS: 00000246 ORIG_RAX: 000000000000009b
RAX: ffffffffffffffda RBX: 00007f43a4936208 RCX: 00007f43a477e719
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 00000000200001c0
RBP: 00007f43a47f139e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f43a4936208 R15: 00007ffcd84dd7c8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/11:
 #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: ffffc90000107d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000107d00 ((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
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
4 locks held by kworker/u8:2/35:
5 locks held by kworker/u8:3/52:
4 locks held by udevd/5203:
 #0: ffff88807fd31418 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182
 #1: ffff88802436cc88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154
 #2: ffff8880342e92d8 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155
 #3: ffff8880614da0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #3: ffff8880614da0e8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2736
1 lock held by dhcpcd/5497:
 #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1aa0 net/ipv4/devinet.c:1112
2 locks held by getty/5599:
 #0: ffff8880356620a0 (&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
2 locks held by kworker/u8:8/5975:
3 locks held by syz.1.20/6003:
1 lock held by syz.1.20/6006:
 #0: ffff88807a978cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #0: ffff88807a978cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: do_lock_mount+0x112/0x3a0 fs/namespace.c:2607
1 lock held by syz.1.20/6024:
 #0: ffff88807a978cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #0: ffff88807a978cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: do_lock_mount+0x112/0x3a0 fs/namespace.c:2607
1 lock held by syz.1.20/6025:
 #0: ffff88807a978cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:825 [inline]
 #0: ffff88807a978cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1748
1 lock held by syz-executor/6857:
 #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
 #0: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517
7 locks held by syz-executor/7032:
 #0: ffff888031130420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888031130420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888034827088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff88802780c788 (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: ffff8880614da0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #4: ffff8880614da0e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005
 #5: ffff88806258e250 (&devlink->lock_key#14){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1537
 #6: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:678 [inline]
 #6: ffffffff8fcc13c8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_create+0x408/0x890 drivers/net/netdevsim/netdev.c:750
4 locks held by syz-executor/7190:
 #0: ffff888031130420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888031130420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #1: ffff888030b9f088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325
 #2: ffff88802780c878 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326
 #3: ffffffff8f55f208 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
2 locks held by syz.1.186/7310:
2 locks held by syz.0.190/7340:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #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: 7310 Comm: syz.1.186 Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
RIP: 0010:unwind_next_frame+0xb89/0x22d0 arch/x86/kernel/unwind_orc.c:585
Code: 5c 24 40 49 8b 6d 08 49 8d 5d 10 49 89 df 49 c1 ef 03 43 80 3c 27 00 74 08 48 89 df e8 c0 1a ba 00 4c 8b 74 24 08 4d 8b 66 10 <48> b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 84 c0 0f
RSP: 0018:ffffc90002f4f1b0 EFLAGS: 00000246
RAX: 1ffff920005e9e51 RBX: ffffc90002f4f290 RCX: ffffffff9035cb20
RDX: ffffffff90afb582 RSI: 0000000000000002 RDI: ffffffff814156e0
RBP: ffffc90002f48000 R08: 0000000000000001 R09: ffffc90002f4f370
R10: ffffc90002f4f2d0 R11: ffffffff81809260 R12: ffffc90002f50000
R13: ffffc90002f4f280 R14: ffffc90002f4f280 R15: 1ffff920005e9e52
FS:  00007f485c3696c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f17561ff000 CR3: 0000000064902000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 save_stack+0xfb/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x76/0x430 mm/page_owner.c:297
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_folios+0xee2/0x18a0 mm/page_alloc.c:2686
 folios_put_refs+0x76c/0x860 mm/swap.c:1007
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x64c/0x1cf0 mm/shmem.c:1032
 shmem_truncate_range mm/shmem.c:1144 [inline]
 shmem_evict_inode+0x29b/0xa80 mm/shmem.c:1274
 evict+0x4e8/0x9b0 fs/inode.c:725
 __dentry_kill+0x20d/0x630 fs/dcache.c:615
 dput+0x19f/0x2b0 fs/dcache.c:857
 __fput+0x5d2/0x880 fs/file_table.c:439
 __do_sys_close fs/open.c:1567 [inline]
 __se_sys_close fs/open.c:1552 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1552
 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: 0033:0x7f485b57d3aa
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 13 8c 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 73 8c 02 00 8b 44 24
RSP: 002b:00007f485c368e00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f485b57d3aa
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000010 R08: 0000000000000000 R09: 0000000000005598
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f485c368ef0 R14: 00007f485c368eb0 R15: 00007f4851400000
 </TASK>