INFO: task syz.7.204:7740 blocked for more than 143 seconds.
Not tainted 6.15.0-rc5-syzkaller-00275-gbec6f00f120e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.204 state:D stack:27096 pid:7740 tgid:7690 ppid:6913 task_flags:0x400040 flags:0x00000004
Call Trace:
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_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1694
inode_lock_nested include/linux/fs.h:902 [inline]
filename_create+0x1f9/0x470 fs/namei.c:4132
do_mknodat+0x184/0x4d0 fs/namei.c:4265
__do_sys_mknod fs/namei.c:4311 [inline]
__se_sys_mknod fs/namei.c:4309 [inline]
__x64_sys_mknod+0x8c/0xa0 fs/namei.c:4309
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: 0033:0x7f209a38e969
RSP: 002b:00007f209b2bd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f209a5b6080 RCX: 00007f209a38e969
RDX: 000000000000070f RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007f209a410ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f209a5b6080 R15: 00007ffc9a5ac2c8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
3 locks held by kworker/u8:2/36:
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90000ad7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000ad7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
3 locks held by kworker/u8:4/64:
#0: ffff88814dab7148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88814dab7148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000155fc60 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000155fc60 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4738
5 locks held by kworker/u8:5/970:
#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: ffffc90003967c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90003967c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2d5c10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608
#3: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12514
#4: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#4: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
1 lock held by dhcpcd/5486:
#0: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x20f/0x330 net/ipv6/addrconf.c:4803
2 locks held by getty/5583:
#0: ffff888034e620a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5833:
#0: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
#0: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3390
5 locks held by syz.7.204/7692:
#0: ffff88802f976420 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff8880594b1078 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#1: ffff8880594b1078 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline]
#1: ffff8880594b1078 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036
#2: ffff8880594b1460 (&inode->ei_update_lock#3){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:569
#3: ffff88804de04228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#3: ffff88804de04228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#3: ffff88804de04228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3202
#4: ffff88804de26590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179
2 locks held by syz.7.204/7740:
#0: ffff88802f976420 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff8880594b1078 (&sb->s_type->i_mutex_key#24/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline]
#1: ffff8880594b1078 (&sb->s_type->i_mutex_key#24/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4132
1 lock held by bch-copygc/loop/7736:
1 lock held by syz-executor/8748:
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
2 locks held by syz-executor/9895:
#0: ffffffff8f7de1b0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8f7de1b0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8f7de1b0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f2e2748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00275-gbec6f00f120e #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
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+0x70e/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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6102 Comm: syz-executor Not tainted 6.15.0-rc5-syzkaller-00275-gbec6f00f120e #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 0e 2c 89 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 df fa e8 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc9000419f310 EFLAGS: 00000002
RAX: 1ffffffff3362f00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff99b17c10 R08: ffff888024100237 R09: 1ffff11004820046
R10: dffffc0000000000 R11: ffffffff8536a2e0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99b17980 R15: 0000000000000000
FS: 0000555588ab0500(0000) GS:ffff888126100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555580fab608 CR3: 00000000558e2000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x19e/0x2f0 drivers/tty/serial/8250/8250_port.c:2098
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
_printk+0xcf/0x120 kernel/printk/printk.c:2475
_udf_warn+0x122/0x170 fs/udf/super.c:2352
udf_evict_inode+0x216/0x3f0 fs/udf/inode.c:149
evict+0x501/0x9c0 fs/inode.c:810
dispose_list fs/inode.c:852 [inline]
evict_inodes+0x636/0x6c0 fs/inode.c:906
generic_shutdown_super+0x9a/0x2c0 fs/super.c:627
kill_block_super+0x44/0x90 fs/super.c:1710
deactivate_locked_super+0xb9/0x130 fs/super.c:473
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1431
task_work_run+0x1d1/0x260 kernel/task_work.c:227
resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218
do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4223f8fc97
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fff700241a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f422401089d RCX: 00007f4223f8fc97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff70024260
RBP: 00007fff70024260 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff700252f0
R13: 00007f422401089d R14: 0000000000051a5e R15: 00007fff70025330