Extracting prog: 2m17.736843063s Minimizing prog: 8m49.830660373s Simplifying prog options: 2m45.871537272s Extracting C: 57.039985294s Simplifying C: 8m58.64453855s 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 crashed: possible deadlock in console_flush_all single: successfully extracted reproducer found reproducer with 3 syscalls minimizing guilty program testing program (duration=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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 task_rq_lock a never seen crash title: possible deadlock in task_rq_lock, ignore simplifying guilty program options testing program (duration=45.44971831s, {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 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 extracting C reproducer testing compiled C program (duration=45.44971831s, {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 simplifying C reproducer testing compiled C program (duration=45.44971831s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false 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 did not crash testing compiled C program (duration=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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=45.44971831s, {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 29m10.777558928s repro crashed as (corrupted=false): ------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.17/6004 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 native_irq_enable arch/x86/include/asm/irqflags.h:42 [inline] arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline] raw_spin_rq_unlock_irq kernel/sched/sched.h:1568 [inline] finish_lock_switch kernel/sched/core.c:4997 [inline] finish_task_switch+0x242/0x940 kernel/sched/core.c:5114 context_switch kernel/sched/core.c:5261 [inline] __schedule+0x1516/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_hrtimeout_range_clock+0x1c5/0x2f0 kernel/time/sleep_timeout.c:207 poll_schedule_timeout+0xd1/0x1b0 fs/select.c:241 do_poll fs/select.c:954 [inline] do_sys_poll+0x73b/0x1070 fs/select.c:1005 __do_sys_ppoll fs/select.c:1111 [inline] __se_sys_ppoll+0x1ff/0x260 fs/select.c:1091 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 -> #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 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:758 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 -> #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.0.17/6004: #0: ffff888075a7f928 (&pi_futex_key){....}-{2:2}, at: rt_mutex_cleanup_proxy_lock+0x23/0x100 kernel/locking/rtmutex_api.c:440 #1: ffff88802c554768 (&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: 6004 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: 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:ffffc90002f97850 EFLAGS: 00010046 RAX: 1ffff110058aa7a0 RBX: ffffffff8dcbdf90 RCX: ffffffff8193220f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802c553d00 RBP: ffff88802c553fa8 R08: ffff88802c553d07 R09: 1ffff110058aa7a0 R10: dffffc0000000000 R11: ffffed10058aa7a1 R12: dffffc0000000000 R13: ffff88802c553d00 R14: ffff8880b863ab00 R15: ffff88802c553d00 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: 0033:0x7ff70b38f749 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:00007ffca40005f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007ff70b5e5fa0 RCX: 00007ff70b38f749 RDX: 0000000000000002 RSI: 0000000000000086 RDI: 000020000000cffc RBP: 00007ff70b413f91 R08: 0000000000000000 R09: 00000000fffffffc R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff70b5e5fa0 R14: 00007ff70b5e5fa0 R15: 0000000000000006 WARNING: kernel/sched/core.c:10852 at sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851, CPU#1: syz.0.17/6004 Modules linked in: CPU: 1 UID: 0 PID: 6004 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:ffffc90002f97850 EFLAGS: 00010046 RAX: 1ffff110058aa7a0 RBX: ffffffff8dcbdf90 RCX: ffffffff8193220f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802c553d00 RBP: ffff88802c553fa8 R08: ffff88802c553d07 R09: 1ffff110058aa7a0 R10: dffffc0000000000 R11: ffffed10058aa7a1 R12: dffffc0000000000 R13: ffff88802c553d00 R14: ffff8880b863ab00 R15: ffff88802c553d00 FS: 0000555564086500(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000cffc CR3: 0000000075be4000 CR4: 00000000003526f0 Call Trace: 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: 0033:0x7ff70b38f749 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:00007ffca40005f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007ff70b5e5fa0 RCX: 00007ff70b38f749 RDX: 0000000000000002 RSI: 0000000000000086 RDI: 000020000000cffc RBP: 00007ff70b413f91 R08: 0000000000000000 R09: 00000000fffffffc R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff70b5e5fa0 R14: 00007ff70b5e5fa0 R15: 0000000000000006 final repro crashed as (corrupted=false): ------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.17/6004 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 native_irq_enable arch/x86/include/asm/irqflags.h:42 [inline] arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline] raw_spin_rq_unlock_irq kernel/sched/sched.h:1568 [inline] finish_lock_switch kernel/sched/core.c:4997 [inline] finish_task_switch+0x242/0x940 kernel/sched/core.c:5114 context_switch kernel/sched/core.c:5261 [inline] __schedule+0x1516/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_hrtimeout_range_clock+0x1c5/0x2f0 kernel/time/sleep_timeout.c:207 poll_schedule_timeout+0xd1/0x1b0 fs/select.c:241 do_poll fs/select.c:954 [inline] do_sys_poll+0x73b/0x1070 fs/select.c:1005 __do_sys_ppoll fs/select.c:1111 [inline] __se_sys_ppoll+0x1ff/0x260 fs/select.c:1091 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 -> #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 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:758 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 -> #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.0.17/6004: #0: ffff888075a7f928 (&pi_futex_key){....}-{2:2}, at: rt_mutex_cleanup_proxy_lock+0x23/0x100 kernel/locking/rtmutex_api.c:440 #1: ffff88802c554768 (&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: 6004 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: 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:ffffc90002f97850 EFLAGS: 00010046 RAX: 1ffff110058aa7a0 RBX: ffffffff8dcbdf90 RCX: ffffffff8193220f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802c553d00 RBP: ffff88802c553fa8 R08: ffff88802c553d07 R09: 1ffff110058aa7a0 R10: dffffc0000000000 R11: ffffed10058aa7a1 R12: dffffc0000000000 R13: ffff88802c553d00 R14: ffff8880b863ab00 R15: ffff88802c553d00 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: 0033:0x7ff70b38f749 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:00007ffca40005f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007ff70b5e5fa0 RCX: 00007ff70b38f749 RDX: 0000000000000002 RSI: 0000000000000086 RDI: 000020000000cffc RBP: 00007ff70b413f91 R08: 0000000000000000 R09: 00000000fffffffc R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff70b5e5fa0 R14: 00007ff70b5e5fa0 R15: 0000000000000006 WARNING: kernel/sched/core.c:10852 at sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851, CPU#1: syz.0.17/6004 Modules linked in: CPU: 1 UID: 0 PID: 6004 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:ffffc90002f97850 EFLAGS: 00010046 RAX: 1ffff110058aa7a0 RBX: ffffffff8dcbdf90 RCX: ffffffff8193220f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802c553d00 RBP: ffff88802c553fa8 R08: ffff88802c553d07 R09: 1ffff110058aa7a0 R10: dffffc0000000000 R11: ffffed10058aa7a1 R12: dffffc0000000000 R13: ffff88802c553d00 R14: ffff8880b863ab00 R15: ffff88802c553d00 FS: 0000555564086500(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000cffc CR3: 0000000075be4000 CR4: 00000000003526f0 Call Trace: 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: 0033:0x7ff70b38f749 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:00007ffca40005f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007ff70b5e5fa0 RCX: 00007ff70b38f749 RDX: 0000000000000002 RSI: 0000000000000086 RDI: 000020000000cffc RBP: 00007ff70b413f91 R08: 0000000000000000 R09: 00000000fffffffc R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff70b5e5fa0 R14: 00007ff70b5e5fa0 R15: 0000000000000006