INFO: task syz.6.1120:17665 blocked for more than 143 seconds.
Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1120 state:D stack:24440 pid:17665 tgid:17662 ppid:13396 task_flags:0x400140 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
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746
fdget_pos+0x247/0x320 fs/file.c:1213
class_fd_pos_constructor include/linux/file.h:85 [inline]
do_writev+0x81/0x2d0 fs/read_write.c:1092
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: 0033:0x7f8110b8e969
RSP: 002b:00007f8111a01038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f8110db5fa0 RCX: 00007f8110b8e969
RDX: 0000000000000001 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f8110c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8110db5fa0 R15: 00007ffc58d8d0f8
INFO: task syz.6.1120:17676 blocked for more than 144 seconds.
Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1120 state:D stack:26840 pid:17676 tgid:17662 ppid:13396 task_flags:0x400040 flags:0x00004006
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_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084
__down_read_common kernel/locking/rwsem.c:1248 [inline]
__down_read kernel/locking/rwsem.c:1261 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526
__super_lock fs/super.c:58 [inline]
super_lock+0x2a9/0x3b0 fs/super.c:120
super_lock_shared fs/super.c:139 [inline]
iterate_supers+0x80/0x180 fs/super.c:931
drop_caches_sysctl_handler+0x97/0x170 fs/drop_caches.c:64
proc_sys_call_handler+0x509/0x7c0 fs/proc/proc_sysctl.c:601
do_iter_readv_writev+0x56b/0x7f0 fs/read_write.c:-1
vfs_writev+0x306/0x9a0 fs/read_write.c:1055
do_writev+0x14d/0x2d0 fs/read_write.c:1101
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: 0033:0x7f8110b8e969
RSP: 002b:00007f81119e0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f8110db6080 RCX: 00007f8110b8e969
RDX: 0000000000000001 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f8110c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8110db6080 R15: 00007ffc58d8d0f8
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
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/u8:3/53:
#0: ffff88814d0ca148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88814d0ca148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90000be7c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000be7c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e2548 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f2e2548 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4195
2 locks held by getty/5574:
#0: ffff8880308d50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/u8:9/6740:
4 locks held by syz-executor/12918:
1 lock held by syz.6.1120/17665:
#0: ffff888034f8f5f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213
3 locks held by syz.6.1120/17676:
#0: ffff888034f8f5f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213
#1: ffff88807a9ba420 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
#1: ffff88807a9ba420 (sb_writers#3){.+.+}-{0:0}, at: vfs_writev+0x274/0x9a0 fs/read_write.c:1053
#2: ffff88804208a0e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#2: ffff88804208a0e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
1 lock held by syz.3.1187/18830:
#0: ffff88804208a0e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88804208a0e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
1 lock held by syz-executor/19203:
3 locks held by syz.7.1259/19237:
#0: ffff888079f38d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213
#1: ffff888061e7c420 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
#1: ffff888061e7c420 (sb_writers#3){.+.+}-{0:0}, at: vfs_writev+0x274/0x9a0 fs/read_write.c:1053
#2: ffff88804208a0e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#2: ffff88804208a0e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
5 locks held by syz.5.1273/19369:
3 locks held by syz-executor/19453:
#0: ffffffff8f2e2548 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f2e2548 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f2e2548 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064
#1: ffff888054b494e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50
#2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
1 lock held by syz.6.1278/19465:
#0: ffff88804208a0e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88804208a0e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
1 lock held by syz.8.1286/19645:
#0: ffffffff8e598548 (bch_fs_list_lock){+.+.}-{4:4}, at: bch2_fs_alloc fs/bcachefs/super.c:967 [inline]
#0: ffffffff8e598548 (bch_fs_list_lock){+.+.}-{4:4}, at: bch2_fs_open+0x27d3/0x2820 fs/bcachefs/super.c:2205
3 locks held by syz.0.1287/19654:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
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: 19654 Comm: syz.0.1287 Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 ee 2a 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 bf f9 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:ffffc90003d6ed10 EFLAGS: 00000002
RAX: 1ffffffff3363560 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000051d5f RDI: 0000000000051d60
RBP: ffffffff99b1ac10 R08: ffff888023ff8237 R09: 1ffff110047ff046
R10: dffffc0000000000 R11: ffffffff8536a420 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99b1a980 R15: 0000000000000000
FS: 00007ff6b56d46c0(0000) GS:ffff8881260fd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff2d5910d8 CR3: 000000004b2bc000 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+0xce/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
bch2_print_maybe_redirect fs/bcachefs/super.c:110 [inline]
__bch2_print+0x176/0x220 fs/bcachefs/super.c:129
bch2_fs_initialize+0x12a/0x13c0 fs/bcachefs/recovery.c:1091
bch2_fs_start+0x6fb/0xae0 fs/bcachefs/super.c:1092
bch2_fs_get_tree+0xd99/0x13a0 fs/bcachefs/fs.c:2570
vfs_get_tree+0x8f/0x2b0 fs/super.c:1759
do_new_mount+0x24a/0xa40 fs/namespace.c:3884
do_mount fs/namespace.c:4224 [inline]
__do_sys_mount fs/namespace.c:4435 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4412
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: 0033:0x7ff6b479010a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff6b56d3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff6b56d3ef0 RCX: 00007ff6b479010a
RDX: 0000200000000040 RSI: 0000200000000100 RDI: 00007ff6b56d3eb0
RBP: 0000200000000040 R08: 00007ff6b56d3ef0 R09: 0000000002000000
R10: 0000000002000000 R11: 0000000000000246 R12: 0000200000000100
R13: 00007ff6b56d3eb0 R14: 0000000000005a9c R15: 0000200000000080