Extracting prog: 2m26.789143283s
Minimizing prog: 9m7.596805902s
Simplifying prog options: 0s
Extracting C: 53.88250338s
Simplifying C: 11m3.655058834s
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, &(0x7f0000000140)={0x8, 0x8b}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x8)
futex(&(0x7f0000000180)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program crashed: possible deadlock in console_flush_all
single: successfully extracted reproducer
found reproducer with 3 syscalls
minimizing guilty program
testing program (duration=49.898617699s, {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, &(0x7f0000000140)={0x8, 0x8b}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x8)
program did not crash
testing program (duration=49.898617699s, {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, &(0x7f0000000140)={0x8, 0x8b}, 0x0)
futex(&(0x7f0000000180)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program did not crash
testing program (duration=49.898617699s, {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)=0x8)
futex(&(0x7f0000000180)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program did not crash
testing program (duration=49.898617699s, {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)=0x8)
futex(&(0x7f0000000180)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program did not crash
testing program (duration=49.898617699s, {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, &(0x7f0000000140)={0x8, 0x8b}, 0x0)
sched_setscheduler(0x0, 0x1, 0x0)
futex(&(0x7f0000000180)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program did not crash
testing program (duration=49.898617699s, {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, &(0x7f0000000140)={0x8, 0x8b}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x8)
futex(0x0, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program did not crash
extracting C reproducer
testing compiled C program (duration=49.898617699s, {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=49.898617699s, {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=49.898617699s, {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=49.898617699s, {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=49.898617699s, {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=49.898617699s, {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=49.898617699s, {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=49.898617699s, {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=49.898617699s, {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=49.898617699s, {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, &(0x7f0000000140)={0x8, 0x8b}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x8)
futex(&(0x7f0000000180)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program crashed: possible deadlock in console_flush_all
validation run: crashed=true
testing program (duration=49.898617699s, {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, &(0x7f0000000140)={0x8, 0x8b}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x8)
futex(&(0x7f0000000180)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program crashed: possible deadlock in console_flush_all
validation run: crashed=true
testing program (duration=49.898617699s, {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, &(0x7f0000000140)={0x8, 0x8b}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000080)=0x8)
futex(&(0x7f0000000180)=0x1, 0x86, 0x2, 0x0, 0x0, 0xfffffffd)
program crashed: possible deadlock in console_flush_all
validation run: crashed=true
reproducing took 29m17.957440273s
repro crashed as (corrupted=false):
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5988 is trying to acquire lock:
ffffffff8e335980 (console_owner){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
ffffffff8e335980 (console_owner){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
ffffffff8e335980 (console_owner){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
ffffffff8e335980 (console_owner){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline]
ffffffff8e335980 (console_owner){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289
but task is already holding lock:
ffff8880b863a918 (&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:2465
kernel_clone+0x21e/0x820 kernel/fork.c:2651
user_mode_thread+0xdd/0x140 kernel/fork.c:2727
rest_init+0x23/0x300 init/main.c:722
start_kernel+0x3a7/0x400 init/main.c:1206
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:211
handle_irq_event_percpu kernel/irq/handle.c:248 [inline]
handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:265
handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
generic_handle_irq_desc include/linux/irqdesc.h:172 [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
lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
prep_new_page mm/page_alloc.c:1854 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2540
folio_prealloc+0x30/0x180 mm/memory.c:-1
wp_page_copy mm/memory.c:3719 [inline]
do_wp_page+0x1231/0x5810 mm/memory.c:4180
handle_pte_fault mm/memory.c:6289 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6580
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
-> #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:211
handle_irq_event_percpu kernel/irq/handle.c:248 [inline]
handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:265
handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
generic_handle_irq_desc include/linux/irqdesc.h:172 [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+0x24d/0x400 init/main.c:1143
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.0.17/5988:
#0: ffff88807947c528 (&pi_futex_key){....}-{2:2}, at: rt_mutex_cleanup_proxy_lock+0x23/0x100 kernel/locking/rtmutex_api.c:440
#1: ffff88802f3028e8 (&p->pi_lock){-.-.}-{2:2}, at: remove_waiter+0x286/0xaf0 kernel/locking/rtmutex.c:1560
#2: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
#3: ffffffff8e3359e0 (console_lock){+.+.}-{0:0}, at: _printk+0xcf/0x120 kernel/printk/printk.c:2451
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline]
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289
stack backtrace:
CPU: 1 UID: 0 PID: 5988 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 e9 be 2e d5 09 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:ffffc90003567850 EFLAGS: 00010046
RAX: 1ffff11005e603d0 RBX: ffffffff8dcb9290 RCX: ffffffff81932d2f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802f301e80
RBP: ffff88802f302128 R08: ffff88802f301e87 R09: 1ffff11005e603d0
R10: dffffc0000000000 R11: ffffed1005e603d1 R12: dffffc0000000000
R13: ffff88802f301e80 R14: ffff8880b863a900 R15: ffff88802f301e80
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: 0033:0x7fc79398f749
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:00007ffd7c9f3ac8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fc793be5fa0 RCX: 00007fc79398f749
RDX: 0000000000000002 RSI: 0000000000000086 RDI: 0000200000000180
RBP: 00007fc793a13f91 R08: 0000000000000000 R09: 00000000fffffffd
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc793be5fa0 R14: 00007fc793be5fa0 R15: 0000000000000006
WARNING: kernel/sched/core.c:10852 at sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851, CPU#1: syz.0.17/5988
Modules linked in:
CPU: 1 UID: 0 PID: 5988 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 e9 be 2e d5 09 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:ffffc90003567850 EFLAGS: 00010046
RAX: 1ffff11005e603d0 RBX: ffffffff8dcb9290 RCX: ffffffff81932d2f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802f301e80
RBP: ffff88802f302128 R08: ffff88802f301e87 R09: 1ffff11005e603d0
R10: dffffc0000000000 R11: ffffed1005e603d1 R12: dffffc0000000000
R13: ffff88802f301e80 R14: ffff8880b863a900 R15: ffff88802f301e80
FS: 0000555562f8b500(0000) GS:ffff888125ae6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557c732004e0 CR3: 0000000079724000 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: 0033:0x7fc79398f749
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:00007ffd7c9f3ac8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fc793be5fa0 RCX: 00007fc79398f749
RDX: 0000000000000002 RSI: 0000000000000086 RDI: 0000200000000180
RBP: 00007fc793a13f91 R08: 0000000000000000 R09: 00000000fffffffd
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc793be5fa0 R14: 00007fc793be5fa0 R15: 0000000000000006
final repro crashed as (corrupted=false):
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5988 is trying to acquire lock:
ffffffff8e335980 (console_owner){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
ffffffff8e335980 (console_owner){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
ffffffff8e335980 (console_owner){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
ffffffff8e335980 (console_owner){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline]
ffffffff8e335980 (console_owner){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289
but task is already holding lock:
ffff8880b863a918 (&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:2465
kernel_clone+0x21e/0x820 kernel/fork.c:2651
user_mode_thread+0xdd/0x140 kernel/fork.c:2727
rest_init+0x23/0x300 init/main.c:722
start_kernel+0x3a7/0x400 init/main.c:1206
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:211
handle_irq_event_percpu kernel/irq/handle.c:248 [inline]
handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:265
handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
generic_handle_irq_desc include/linux/irqdesc.h:172 [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
lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
prep_new_page mm/page_alloc.c:1854 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2540
folio_prealloc+0x30/0x180 mm/memory.c:-1
wp_page_copy mm/memory.c:3719 [inline]
do_wp_page+0x1231/0x5810 mm/memory.c:4180
handle_pte_fault mm/memory.c:6289 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6580
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
-> #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:211
handle_irq_event_percpu kernel/irq/handle.c:248 [inline]
handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:265
handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855
generic_handle_irq_desc include/linux/irqdesc.h:172 [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+0x24d/0x400 init/main.c:1143
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.0.17/5988:
#0: ffff88807947c528 (&pi_futex_key){....}-{2:2}, at: rt_mutex_cleanup_proxy_lock+0x23/0x100 kernel/locking/rtmutex_api.c:440
#1: ffff88802f3028e8 (&p->pi_lock){-.-.}-{2:2}, at: remove_waiter+0x286/0xaf0 kernel/locking/rtmutex.c:1560
#2: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
#3: ffffffff8e3359e0 (console_lock){+.+.}-{0:0}, at: _printk+0xcf/0x120 kernel/printk/printk.c:2451
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline]
#4: ffffffff8e21d298 (console_srcu){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289
stack backtrace:
CPU: 1 UID: 0 PID: 5988 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 e9 be 2e d5 09 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:ffffc90003567850 EFLAGS: 00010046
RAX: 1ffff11005e603d0 RBX: ffffffff8dcb9290 RCX: ffffffff81932d2f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802f301e80
RBP: ffff88802f302128 R08: ffff88802f301e87 R09: 1ffff11005e603d0
R10: dffffc0000000000 R11: ffffed1005e603d1 R12: dffffc0000000000
R13: ffff88802f301e80 R14: ffff8880b863a900 R15: ffff88802f301e80
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: 0033:0x7fc79398f749
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:00007ffd7c9f3ac8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fc793be5fa0 RCX: 00007fc79398f749
RDX: 0000000000000002 RSI: 0000000000000086 RDI: 0000200000000180
RBP: 00007fc793a13f91 R08: 0000000000000000 R09: 00000000fffffffd
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc793be5fa0 R14: 00007fc793be5fa0 R15: 0000000000000006
WARNING: kernel/sched/core.c:10852 at sched_change_end+0x4f6/0x640 kernel/sched/core.c:10851, CPU#1: syz.0.17/5988
Modules linked in:
CPU: 1 UID: 0 PID: 5988 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 e9 be 2e d5 09 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:ffffc90003567850 EFLAGS: 00010046
RAX: 1ffff11005e603d0 RBX: ffffffff8dcb9290 RCX: ffffffff81932d2f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802f301e80
RBP: ffff88802f302128 R08: ffff88802f301e87 R09: 1ffff11005e603d0
R10: dffffc0000000000 R11: ffffed1005e603d1 R12: dffffc0000000000
R13: ffff88802f301e80 R14: ffff8880b863a900 R15: ffff88802f301e80
FS: 0000555562f8b500(0000) GS:ffff888125ae6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557c732004e0 CR3: 0000000079724000 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: 0033:0x7fc79398f749
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:00007ffd7c9f3ac8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fc793be5fa0 RCX: 00007fc79398f749
RDX: 0000000000000002 RSI: 0000000000000086 RDI: 0000200000000180
RBP: 00007fc793a13f91 R08: 0000000000000000 R09: 00000000fffffffd
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc793be5fa0 R14: 00007fc793be5fa0 R15: 0000000000000006