INFO: task syz.4.2603:18277 blocked for more than 143 seconds.
Tainted: G U 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2603 state:D stack:28424 pid:18277 tgid:18270 ppid:18086 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6879
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
___down_common+0x2d8/0x460 kernel/locking/semaphore.c:268
__down_common kernel/locking/semaphore.c:293 [inline]
__down+0x20/0x30 kernel/locking/semaphore.c:303
down+0x74/0xa0 kernel/locking/semaphore.c:100
console_lock+0x5b/0xa0 kernel/printk/printk.c:2849
activate+0x52/0x100 drivers/video/fbdev/core/fbsysfs.c:22
store_bpp+0x114/0x1a0 drivers/video/fbdev/core/fbsysfs.c:151
dev_attr_store+0x55/0x80 drivers/base/core.c:2440
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x354/0x510 fs/kernfs/file.c:334
iter_file_splice_write+0x91f/0x1150 fs/splice.c:738
do_splice_from fs/splice.c:935 [inline]
direct_splice_actor+0x192/0x6c0 fs/splice.c:1158
splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102
do_splice_direct_actor fs/splice.c:1201 [inline]
do_splice_direct+0x174/0x240 fs/splice.c:1227
do_sendfile+0xb06/0xe50 fs/read_write.c:1370
__do_sys_sendfile64 fs/read_write.c:1431 [inline]
__se_sys_sendfile64 fs/read_write.c:1417 [inline]
__x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1417
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc89698e9a9
RSP: 002b:00007fc8977fc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fc896bb6240 RCX: 00007fc89698e9a9
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000002
RBP: 00007fc896a10ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc896bb6240 R15: 00007ffd15a41f98
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by kworker/u10:9/9314:
#0: ffff88801f7ca148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000d797d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
2 locks held by syz.3.2580/17921:
#0: ffffffff90408fd0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9de628 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xdd/0x1a40 fs/nfsd/nfsctl.c:1922
2 locks held by getty/18014:
#0: ffff8880325330a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900046832f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
6 locks held by syz.0.2624/18207:
3 locks held by syz.4.2603/18277:
#0: ffff88802522a428 (sb_writers#7){.+.+}-{0:0}, at: splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102
#1: ffff88802df9c488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325
#2: ffff888142b393c8 (kn->active#83){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326
2 locks held by syz-executor/18297:
#0: ffff8880830260e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880830260e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880830260e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880830260e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9de628 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
4 locks held by syz.1.2638/18323:
#0: ffff888035fc1eb8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1217
#1: ffff88802522a428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738
#2: ffff88805c77f888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 fs/kernfs/file.c:325
#3: ffff888142b39e18 (kn->active#146){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 fs/kernfs/file.c:326
2 locks held by syz.8.2687/18818:
#0: ffffffff8f2c8f68 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2c8f68 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
#1: ffff8880891001c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev.part.0+0x37/0x500 drivers/tty/tty_io.c:1406
2 locks held by syz.6.2708/18843:
1 lock held by syz.6.2714/18864:
#0: ffffffff8f2c8f68 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2c8f68 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
4 locks held by syz.6.2714/18866:
#0: ffff88807abc3438 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1217
#1: ffff88803bb169e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#2: ffff88807e81d888 (&of->mutex){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#3: ffff8880216fd2d8 (kn->active#106){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
1 lock held by syz.9.2694/18877:
#0: ffffffff8f2c8f68 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline]
#0: ffffffff8f2c8f68 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53e/0xf90 drivers/tty/tty_io.c:2120
2 locks held by syz.9.2694/18883:
#0: ffffffff9034e590 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570
#1: ffffffff8e5d0278 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304
1 lock held by syz-executor/18884:
2 locks held by syz.2.2721/18894:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:470
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245