Extracting prog: 3m33.651013736s
Minimizing prog: 38m55.023771431s
Simplifying prog options: 0s
Extracting C: 32.81532771s
Simplifying C: 10m38.908122035s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program did not crash
single: failed to extract reproducer
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program crashed: possible deadlock in console_flush_all
single: successfully extracted reproducer
found reproducer with 3 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): sched_setscheduler-futex
detailed listing:
executing program 0:
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, 0x0, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
sched_setscheduler(0x0, 0x1, 0x0)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)
futex(0x0, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
program crashed: possible deadlock in console_flush_all
simplifying C reproducer
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
program crashed: possible deadlock in console_flush_all
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
program crashed: possible deadlock in console_flush_all
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:true Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
program crashed: possible deadlock in console_flush_all
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
program crashed: possible deadlock in console_flush_all
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
program crashed: possible deadlock in console_flush_all
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
program crashed: possible deadlock in console_flush_all
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
program crashed: possible deadlock in console_flush_all
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program crashed: possible deadlock in console_flush_all
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program crashed: possible deadlock in console_flush_all
validation run: crashed=true
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-futex
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000240)={0x8, 0x248}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x7)
futex(&(0x7f000000cffc)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffc)

program crashed: possible deadlock in console_flush_all
validation run: crashed=true
reproducing took 58m43.112385205s
repro crashed as (corrupted=false):
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5987 is trying to acquire lock:
ffffffff8e333180 (console_owner){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
ffffffff8e333180 (console_owner){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
ffffffff8e333180 (console_owner){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
ffffffff8e333180 (console_owner){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline]
ffffffff8e333180 (console_owner){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289

but task is already holding lock:
ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
       raw_spin_rq_lock kernel/sched/sched.h:1556 [inline]
       task_rq_lock+0xbc/0x470 kernel/sched/core.c:739
       cgroup_move_task+0x92/0x2a0 kernel/sched/psi.c:1170
       css_set_move_task+0x658/0x9e0 kernel/cgroup/cgroup.c:951
       cgroup_post_fork+0x1ef/0x7a0 kernel/cgroup/cgroup.c:6913
       copy_process+0x3614/0x3950 kernel/fork.c:2469
       kernel_clone+0x21e/0x820 kernel/fork.c:2655
       user_mode_thread+0xdd/0x140 kernel/fork.c:2731
       rest_init+0x23/0x300 init/main.c:723
       start_kernel+0x3ac/0x400 init/main.c:1208
       x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x147

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
       try_to_wake_up+0x67/0x12b0 kernel/sched/core.c:4108
       __wake_up_common kernel/sched/wait.c:108 [inline]
       __wake_up_common_lock+0x137/0x1f0 kernel/sched/wait.c:125
       tty_port_default_wakeup+0xfb/0x170 drivers/tty/tty_port.c:67
       serial8250_tx_chars+0x72e/0x970 drivers/tty/serial/8250/8250_port.c:1719
       serial8250_handle_irq+0x633/0xbb0 drivers/tty/serial/8250/8250_port.c:1827
       serial8250_default_handle_irq+0xbf/0x200 drivers/tty/serial/8250/8250_port.c:1846
       serial8250_interrupt+0x8d/0x180 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x285/0xa60 kernel/irq/handle.c:209
       handle_irq_event_percpu kernel/irq/handle.c:246 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:263
       handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
       generic_handle_irq_desc include/linux/irqdesc.h:186 [inline]
       handle_irq arch/x86/kernel/irq.c:255 [inline]
       call_irq_handler arch/x86/kernel/irq.c:-1 [inline]
       __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:326
       common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:319
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       srcu_funnel_gp_start kernel/rcu/srcutree.c:1161 [inline]
       srcu_gp_start_if_needed+0x769/0xaf0 kernel/rcu/srcutree.c:1420
       __call_srcu kernel/rcu/srcutree.c:1465 [inline]
       __synchronize_srcu+0x2f0/0x390 kernel/rcu/srcutree.c:1517
       fsnotify_connector_destroy_workfn+0x44/0xb0 fs/notify/mark.c:322
       process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
       process_scheduled_works kernel/workqueue.c:3362 [inline]
       worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
       kthread+0x711/0x8a0 kernel/kthread.c:463
       ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

-> #2 (&tty->write_wait){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       __wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:124
       tty_port_default_wakeup+0xfb/0x170 drivers/tty/tty_port.c:67
       serial8250_tx_chars+0x72e/0x970 drivers/tty/serial/8250/8250_port.c:1719
       serial8250_handle_irq+0x633/0xbb0 drivers/tty/serial/8250/8250_port.c:1827
       serial8250_default_handle_irq+0xbf/0x200 drivers/tty/serial/8250/8250_port.c:1846
       serial8250_interrupt+0x8d/0x180 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x285/0xa60 kernel/irq/handle.c:209
       handle_irq_event_percpu kernel/irq/handle.c:246 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:263
       handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
       generic_handle_irq_desc include/linux/irqdesc.h:186 [inline]
       handle_irq arch/x86/kernel/irq.c:255 [inline]
       call_irq_handler arch/x86/kernel/irq.c:-1 [inline]
       __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:326
       common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:319
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
       uart_port_unlock_deref+0x111/0x2f0 drivers/tty/serial/serial_core.c:91
       uart_write+0xe8/0x130 drivers/tty/serial/serial_core.c:634
       process_output_block drivers/tty/n_tty.c:557 [inline]
       n_tty_write+0xd78/0x12a0 drivers/tty/n_tty.c:2366
       iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
       file_tty_write+0x559/0xa20 drivers/tty/tty_io.c:1081
       new_sync_write fs/read_write.c:593 [inline]
       vfs_write+0x5c9/0xb30 fs/read_write.c:686
       ksys_write+0x145/0x250 fs/read_write.c:738
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:717 [inline]
       serial8250_console_write+0x17e/0x1ba0 drivers/tty/serial/8250/8250_port.c:3301
       console_emit_next_record kernel/printk/printk.c:3129 [inline]
       console_flush_one_record kernel/printk/printk.c:3215 [inline]
       console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
       __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
       console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
       vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
       _printk+0xcf/0x120 kernel/printk/printk.c:2451
       register_console+0xa8b/0xf90 kernel/printk/printk.c:4170
       univ8250_console_init+0x3a/0x70 drivers/tty/serial/8250/8250_core.c:515
       console_init+0xfc/0x3f0 kernel/printk/printk.c:4369
       start_kernel+0x252/0x400 init/main.c:1145
       x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x147

-> #0 (console_owner){....}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
       console_lock_spinning_enable kernel/printk/printk.c:1900 [inline]
       console_emit_next_record kernel/printk/printk.c:3123 [inline]
       console_flush_one_record kernel/printk/printk.c:3215 [inline]
       console_flush_all+0x6ee/0xb60 kernel/printk/printk.c:3289
       __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
       console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
       vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
       _printk+0xcf/0x120 kernel/printk/printk.c:2451
       __report_bug+0x305/0x500 lib/bug.c:243
       report_bug+0x16a/0x220 lib/bug.c:281
       handle_bug+0x98/0x200 arch/x86/kernel/traps.c:435
       exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:489
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:616
       sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851
       class_sched_change_destructor kernel/sched/sched.h:3956 [inline]
       rt_mutex_setprio+0x488/0xb70 kernel/sched/core.c:7331
       rt_mutex_adjust_prio kernel/locking/rtmutex.c:539 [inline]
       remove_waiter+0x7f5/0xaf0 kernel/locking/rtmutex.c:1567
       rt_mutex_cleanup_proxy_lock+0x6c/0x100 kernel/locking/rtmutex_api.c:458
       futex_lock_pi+0x530/0xa90 kernel/futex/pi.c:1067
       do_futex+0x292/0x420 kernel/futex/syscalls.c:146
       __do_sys_futex kernel/futex/syscalls.c:207 [inline]
       __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  console_owner --> &p->pi_lock --> &rq->__lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rq->__lock);
                               lock(&p->pi_lock);
                               lock(&rq->__lock);
  lock(console_owner);

 *** DEADLOCK ***

5 locks held by syz.0.17/5987:
 #0: ffff888075889828 (&pi_futex_key){....}-{2:2}, at: rt_mutex_cleanup_proxy_lock+0x23/0x100 kernel/locking/rtmutex_api.c:440
 #1: ffff88807d02a8e8 (&p->pi_lock){-.-.}-{2:2}, at: remove_waiter+0x286/0xaf0 kernel/locking/rtmutex.c:1560
 #2: ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
 #3: ffffffff8e3331e0 (console_lock){+.+.}-{0:0}, at: _printk+0xcf/0x120 kernel/printk/printk.c:2451
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline]
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289

stack backtrace:
CPU: 1 UID: 0 PID: 5987 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
 console_lock_spinning_enable kernel/printk/printk.c:1900 [inline]
 console_emit_next_record kernel/printk/printk.c:3123 [inline]
 console_flush_one_record kernel/printk/printk.c:3215 [inline]
 console_flush_all+0x6ee/0xb60 kernel/printk/printk.c:3289
 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
 console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
 vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
 _printk+0xcf/0x120 kernel/printk/printk.c:2451
 __report_bug+0x305/0x500 lib/bug.c:243
 report_bug+0x16a/0x220 lib/bug.c:281
 handle_bug+0x98/0x200 arch/x86/kernel/traps.c:435
 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:489
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:616
RIP: 0010:sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851
Code: 00 74 26 48 83 c4 38 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 e9 1d fc ff ff 90 0f 0b 90 e9 86 fc ff ff 90 <0f> 0b 90 eb d4 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 49 fb ff ff 48
RSP: 0018:ffffc90002f67850 EFLAGS: 00010046
RAX: 1ffff1100fa053d0 RBX: ffffffff8dcbdf90 RCX: ffffffff8193220f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807d029e80
RBP: ffff88807d02a128 R08: ffff88807d029e87 R09: 1ffff1100fa053d0
R10: dffffc0000000000 R11: ffffed100fa053d1 R12: dffffc0000000000
R13: ffff88807d029e80 R14: ffff8880b863ab00 R15: ffff88807d029e80
 class_sched_change_destructor kernel/sched/sched.h:3956 [inline]
 rt_mutex_setprio+0x488/0xb70 kernel/sched/core.c:7331
 rt_mutex_adjust_prio kernel/locking/rtmutex.c:539 [inline]
 remove_waiter+0x7f5/0xaf0 kernel/locking/rtmutex.c:1567
 rt_mutex_cleanup_proxy_lock+0x6c/0x100 kernel/locking/rtmutex_api.c:458
 futex_lock_pi+0x530/0xa90 kernel/futex/pi.c:1067
 do_futex+0x292/0x420 kernel/futex/syscalls.c:146
 __do_sys_futex kernel/futex/syscalls.c:207 [inline]
 __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f411198f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007ffcfbf89a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f4111be5fa0 RCX: 00007f411198f749
RDX: 0000000000000002 RSI: 0000000000000086 RDI: 000020000000cffc
RBP: 00007f4111a13f91 R08: 0000000000000000 R09: 00000000fffffffc
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4111be5fa0 R14: 00007f4111be5fa0 R15: 0000000000000006
 </TASK>
WARNING: kernel/sched/core.c:10852 at sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851, CPU#1: syz.0.17/5987
Modules linked in:
CPU: 1 UID: 0 PID: 5987 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851
Code: 00 74 26 48 83 c4 38 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 e9 1d fc ff ff 90 0f 0b 90 e9 86 fc ff ff 90 <0f> 0b 90 eb d4 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 49 fb ff ff 48
RSP: 0018:ffffc90002f67850 EFLAGS: 00010046
RAX: 1ffff1100fa053d0 RBX: ffffffff8dcbdf90 RCX: ffffffff8193220f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807d029e80
RBP: ffff88807d02a128 R08: ffff88807d029e87 R09: 1ffff1100fa053d0
R10: dffffc0000000000 R11: ffffed100fa053d1 R12: dffffc0000000000
R13: ffff88807d029e80 R14: ffff8880b863ab00 R15: ffff88807d029e80
FS:  000055556f95a500(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000cffc CR3: 00000000759c4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 class_sched_change_destructor kernel/sched/sched.h:3956 [inline]
 rt_mutex_setprio+0x488/0xb70 kernel/sched/core.c:7331
 rt_mutex_adjust_prio kernel/locking/rtmutex.c:539 [inline]
 remove_waiter+0x7f5/0xaf0 kernel/locking/rtmutex.c:1567
 rt_mutex_cleanup_proxy_lock+0x6c/0x100 kernel/locking/rtmutex_api.c:458
 futex_lock_pi+0x530/0xa90 kernel/futex/pi.c:1067
 do_futex+0x292/0x420 kernel/futex/syscalls.c:146
 __do_sys_futex kernel/futex/syscalls.c:207 [inline]
 __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f411198f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007ffcfbf89a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f4111be5fa0 RCX: 00007f411198f749
RDX: 0000000000000002 RSI: 0000000000000086 RDI: 000020000000cffc
RBP: 00007f4111a13f91 R08: 0000000000000000 R09: 00000000fffffffc
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4111be5fa0 R14: 00007f4111be5fa0 R15: 0000000000000006
 </TASK>

final repro crashed as (corrupted=false):
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5987 is trying to acquire lock:
ffffffff8e333180 (console_owner){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
ffffffff8e333180 (console_owner){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
ffffffff8e333180 (console_owner){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
ffffffff8e333180 (console_owner){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline]
ffffffff8e333180 (console_owner){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289

but task is already holding lock:
ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
       raw_spin_rq_lock kernel/sched/sched.h:1556 [inline]
       task_rq_lock+0xbc/0x470 kernel/sched/core.c:739
       cgroup_move_task+0x92/0x2a0 kernel/sched/psi.c:1170
       css_set_move_task+0x658/0x9e0 kernel/cgroup/cgroup.c:951
       cgroup_post_fork+0x1ef/0x7a0 kernel/cgroup/cgroup.c:6913
       copy_process+0x3614/0x3950 kernel/fork.c:2469
       kernel_clone+0x21e/0x820 kernel/fork.c:2655
       user_mode_thread+0xdd/0x140 kernel/fork.c:2731
       rest_init+0x23/0x300 init/main.c:723
       start_kernel+0x3ac/0x400 init/main.c:1208
       x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x147

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
       try_to_wake_up+0x67/0x12b0 kernel/sched/core.c:4108
       __wake_up_common kernel/sched/wait.c:108 [inline]
       __wake_up_common_lock+0x137/0x1f0 kernel/sched/wait.c:125
       tty_port_default_wakeup+0xfb/0x170 drivers/tty/tty_port.c:67
       serial8250_tx_chars+0x72e/0x970 drivers/tty/serial/8250/8250_port.c:1719
       serial8250_handle_irq+0x633/0xbb0 drivers/tty/serial/8250/8250_port.c:1827
       serial8250_default_handle_irq+0xbf/0x200 drivers/tty/serial/8250/8250_port.c:1846
       serial8250_interrupt+0x8d/0x180 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x285/0xa60 kernel/irq/handle.c:209
       handle_irq_event_percpu kernel/irq/handle.c:246 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:263
       handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
       generic_handle_irq_desc include/linux/irqdesc.h:186 [inline]
       handle_irq arch/x86/kernel/irq.c:255 [inline]
       call_irq_handler arch/x86/kernel/irq.c:-1 [inline]
       __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:326
       common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:319
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       srcu_funnel_gp_start kernel/rcu/srcutree.c:1161 [inline]
       srcu_gp_start_if_needed+0x769/0xaf0 kernel/rcu/srcutree.c:1420
       __call_srcu kernel/rcu/srcutree.c:1465 [inline]
       __synchronize_srcu+0x2f0/0x390 kernel/rcu/srcutree.c:1517
       fsnotify_connector_destroy_workfn+0x44/0xb0 fs/notify/mark.c:322
       process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
       process_scheduled_works kernel/workqueue.c:3362 [inline]
       worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
       kthread+0x711/0x8a0 kernel/kthread.c:463
       ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

-> #2 (&tty->write_wait){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       __wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:124
       tty_port_default_wakeup+0xfb/0x170 drivers/tty/tty_port.c:67
       serial8250_tx_chars+0x72e/0x970 drivers/tty/serial/8250/8250_port.c:1719
       serial8250_handle_irq+0x633/0xbb0 drivers/tty/serial/8250/8250_port.c:1827
       serial8250_default_handle_irq+0xbf/0x200 drivers/tty/serial/8250/8250_port.c:1846
       serial8250_interrupt+0x8d/0x180 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x285/0xa60 kernel/irq/handle.c:209
       handle_irq_event_percpu kernel/irq/handle.c:246 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:263
       handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
       generic_handle_irq_desc include/linux/irqdesc.h:186 [inline]
       handle_irq arch/x86/kernel/irq.c:255 [inline]
       call_irq_handler arch/x86/kernel/irq.c:-1 [inline]
       __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:326
       common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:319
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
       uart_port_unlock_deref+0x111/0x2f0 drivers/tty/serial/serial_core.c:91
       uart_write+0xe8/0x130 drivers/tty/serial/serial_core.c:634
       process_output_block drivers/tty/n_tty.c:557 [inline]
       n_tty_write+0xd78/0x12a0 drivers/tty/n_tty.c:2366
       iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
       file_tty_write+0x559/0xa20 drivers/tty/tty_io.c:1081
       new_sync_write fs/read_write.c:593 [inline]
       vfs_write+0x5c9/0xb30 fs/read_write.c:686
       ksys_write+0x145/0x250 fs/read_write.c:738
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:717 [inline]
       serial8250_console_write+0x17e/0x1ba0 drivers/tty/serial/8250/8250_port.c:3301
       console_emit_next_record kernel/printk/printk.c:3129 [inline]
       console_flush_one_record kernel/printk/printk.c:3215 [inline]
       console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
       __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
       console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
       vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
       _printk+0xcf/0x120 kernel/printk/printk.c:2451
       register_console+0xa8b/0xf90 kernel/printk/printk.c:4170
       univ8250_console_init+0x3a/0x70 drivers/tty/serial/8250/8250_core.c:515
       console_init+0xfc/0x3f0 kernel/printk/printk.c:4369
       start_kernel+0x252/0x400 init/main.c:1145
       x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x147

-> #0 (console_owner){....}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
       console_lock_spinning_enable kernel/printk/printk.c:1900 [inline]
       console_emit_next_record kernel/printk/printk.c:3123 [inline]
       console_flush_one_record kernel/printk/printk.c:3215 [inline]
       console_flush_all+0x6ee/0xb60 kernel/printk/printk.c:3289
       __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
       console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
       vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
       _printk+0xcf/0x120 kernel/printk/printk.c:2451
       __report_bug+0x305/0x500 lib/bug.c:243
       report_bug+0x16a/0x220 lib/bug.c:281
       handle_bug+0x98/0x200 arch/x86/kernel/traps.c:435
       exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:489
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:616
       sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851
       class_sched_change_destructor kernel/sched/sched.h:3956 [inline]
       rt_mutex_setprio+0x488/0xb70 kernel/sched/core.c:7331
       rt_mutex_adjust_prio kernel/locking/rtmutex.c:539 [inline]
       remove_waiter+0x7f5/0xaf0 kernel/locking/rtmutex.c:1567
       rt_mutex_cleanup_proxy_lock+0x6c/0x100 kernel/locking/rtmutex_api.c:458
       futex_lock_pi+0x530/0xa90 kernel/futex/pi.c:1067
       do_futex+0x292/0x420 kernel/futex/syscalls.c:146
       __do_sys_futex kernel/futex/syscalls.c:207 [inline]
       __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  console_owner --> &p->pi_lock --> &rq->__lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rq->__lock);
                               lock(&p->pi_lock);
                               lock(&rq->__lock);
  lock(console_owner);

 *** DEADLOCK ***

5 locks held by syz.0.17/5987:
 #0: ffff888075889828 (&pi_futex_key){....}-{2:2}, at: rt_mutex_cleanup_proxy_lock+0x23/0x100 kernel/locking/rtmutex_api.c:440
 #1: ffff88807d02a8e8 (&p->pi_lock){-.-.}-{2:2}, at: remove_waiter+0x286/0xaf0 kernel/locking/rtmutex.c:1560
 #2: ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
 #3: ffffffff8e3331e0 (console_lock){+.+.}-{0:0}, at: _printk+0xcf/0x120 kernel/printk/printk.c:2451
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline]
 #4: ffffffff8e21aa98 (console_srcu){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289

stack backtrace:
CPU: 1 UID: 0 PID: 5987 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
 console_lock_spinning_enable kernel/printk/printk.c:1900 [inline]
 console_emit_next_record kernel/printk/printk.c:3123 [inline]
 console_flush_one_record kernel/printk/printk.c:3215 [inline]
 console_flush_all+0x6ee/0xb60 kernel/printk/printk.c:3289
 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
 console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
 vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
 _printk+0xcf/0x120 kernel/printk/printk.c:2451
 __report_bug+0x305/0x500 lib/bug.c:243
 report_bug+0x16a/0x220 lib/bug.c:281
 handle_bug+0x98/0x200 arch/x86/kernel/traps.c:435
 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:489
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:616
RIP: 0010:sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851
Code: 00 74 26 48 83 c4 38 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 e9 1d fc ff ff 90 0f 0b 90 e9 86 fc ff ff 90 <0f> 0b 90 eb d4 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 49 fb ff ff 48
RSP: 0018:ffffc90002f67850 EFLAGS: 00010046
RAX: 1ffff1100fa053d0 RBX: ffffffff8dcbdf90 RCX: ffffffff8193220f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807d029e80
RBP: ffff88807d02a128 R08: ffff88807d029e87 R09: 1ffff1100fa053d0
R10: dffffc0000000000 R11: ffffed100fa053d1 R12: dffffc0000000000
R13: ffff88807d029e80 R14: ffff8880b863ab00 R15: ffff88807d029e80
 class_sched_change_destructor kernel/sched/sched.h:3956 [inline]
 rt_mutex_setprio+0x488/0xb70 kernel/sched/core.c:7331
 rt_mutex_adjust_prio kernel/locking/rtmutex.c:539 [inline]
 remove_waiter+0x7f5/0xaf0 kernel/locking/rtmutex.c:1567
 rt_mutex_cleanup_proxy_lock+0x6c/0x100 kernel/locking/rtmutex_api.c:458
 futex_lock_pi+0x530/0xa90 kernel/futex/pi.c:1067
 do_futex+0x292/0x420 kernel/futex/syscalls.c:146
 __do_sys_futex kernel/futex/syscalls.c:207 [inline]
 __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f411198f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007ffcfbf89a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f4111be5fa0 RCX: 00007f411198f749
RDX: 0000000000000002 RSI: 0000000000000086 RDI: 000020000000cffc
RBP: 00007f4111a13f91 R08: 0000000000000000 R09: 00000000fffffffc
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4111be5fa0 R14: 00007f4111be5fa0 R15: 0000000000000006
 </TASK>
WARNING: kernel/sched/core.c:10852 at sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851, CPU#1: syz.0.17/5987
Modules linked in:
CPU: 1 UID: 0 PID: 5987 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851
Code: 00 74 26 48 83 c4 38 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 e9 1d fc ff ff 90 0f 0b 90 e9 86 fc ff ff 90 <0f> 0b 90 eb d4 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 49 fb ff ff 48
RSP: 0018:ffffc90002f67850 EFLAGS: 00010046
RAX: 1ffff1100fa053d0 RBX: ffffffff8dcbdf90 RCX: ffffffff8193220f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807d029e80
RBP: ffff88807d02a128 R08: ffff88807d029e87 R09: 1ffff1100fa053d0
R10: dffffc0000000000 R11: ffffed100fa053d1 R12: dffffc0000000000
R13: ffff88807d029e80 R14: ffff8880b863ab00 R15: ffff88807d029e80
FS:  000055556f95a500(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000cffc CR3: 00000000759c4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 class_sched_change_destructor kernel/sched/sched.h:3956 [inline]
 rt_mutex_setprio+0x488/0xb70 kernel/sched/core.c:7331
 rt_mutex_adjust_prio kernel/locking/rtmutex.c:539 [inline]
 remove_waiter+0x7f5/0xaf0 kernel/locking/rtmutex.c:1567
 rt_mutex_cleanup_proxy_lock+0x6c/0x100 kernel/locking/rtmutex_api.c:458
 futex_lock_pi+0x530/0xa90 kernel/futex/pi.c:1067
 do_futex+0x292/0x420 kernel/futex/syscalls.c:146
 __do_sys_futex kernel/futex/syscalls.c:207 [inline]
 __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f411198f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007ffcfbf89a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f4111be5fa0 RCX: 00007f411198f749
RDX: 0000000000000002 RSI: 0000000000000086 RDI: 000020000000cffc
RBP: 00007f4111a13f91 R08: 0000000000000000 R09: 00000000fffffffc
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4111be5fa0 R14: 00007f4111be5fa0 R15: 0000000000000006
 </TASK>