In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Fix unsafe locking in the scx_dump_state()
For built with CONFIG_PREEMPT_RT=y kernels, the dump_lock will be converted
sleepable spinlock and not disable-irq, so the following scenarios occur:
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
irq_work/0/27 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&rq->__lock){?...}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x40
{IN-HARDIRQ-W} state was registered at:
lock_acquire+0x1e1/0x510
_raw_spin_lock_nested+0x42/0x80
raw_spin_rq_lock_nested+0x2b/0x40
sched_tick+0xae/0x7b0
update_process_times+0x14c/0x1b0
tick_periodic+0x62/0x1f0
tick_handle_periodic+0x48/0xf0
timer_interrupt+0x55/0x80
__handle_irq_event_percpu+0x20a/0x5c0
handle_irq_event_percpu+0x18/0xc0
handle_irq_event+0xb5/0x150
handle_level_irq+0x220/0x460
__common_interrupt+0xa2/0x1e0
common_interrupt+0xb0/0xd0
asm_common_interrupt+0x2b/0x40
_raw_spin_unlock_irqrestore+0x45/0x80
__setup_irq+0xc34/0x1a30
request_threaded_irq+0x214/0x2f0
hpet_time_init+0x3e/0x60
x86_late_time_init+0x5b/0xb0
start_kernel+0x308/0x410
x86_64_start_reservations+0x1c/0x30
x86_64_start_kernel+0x96/0xa0
common_startup_64+0x13e/0x148
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&rq->__lock);
<Interrupt>
lock(&rq->__lock);
*** DEADLOCK ***
stack backtrace:
CPU: 0 UID: 0 PID: 27 Comm: irq_work/0
Call Trace:
<TASK>
dump_stack_lvl+0x8c/0xd0
dump_stack+0x14/0x20
print_usage_bug+0x42e/0x690
mark_lock.part.44+0x867/0xa70
? __pfx_mark_lock.part.44+0x10/0x10
? string_nocheck+0x19c/0x310
? number+0x739/0x9f0
? __pfx_string_nocheck+0x10/0x10
? __pfx_check_pointer+0x10/0x10
? kvm_sched_clock_read+0x15/0x30
? sched_clock_noinstr+0xd/0x20
? local_clock_noinstr+0x1c/0xe0
__lock_acquire+0xc4b/0x62b0
? __pfx_format_decode+0x10/0x10
? __pfx_string+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
? __pfx_vsnprintf+0x10/0x10
lock_acquire+0x1e1/0x510
? raw_spin_rq_lock_nested+0x2b/0x40
? __pfx_lock_acquire+0x10/0x10
? dump_line+0x12e/0x270
? raw_spin_rq_lock_nested+0x20/0x40
_raw_spin_lock_nested+0x42/0x80
? raw_spin_rq_lock_nested+0x2b/0x40
raw_spin_rq_lock_nested+0x2b/0x40
scx_dump_state+0x3b3/0x1270
? finish_task_switch+0x27e/0x840
scx_ops_error_irq_workfn+0x67/0x80
irq_work_single+0x113/0x260
irq_work_run_list.part.3+0x44/0x70
run_irq_workd+0x6b/0x90
? __pfx_run_irq_workd+0x10/0x10
smpboot_thread_fn+0x529/0x870
? __pfx_smpboot_thread_fn+0x10/0x10
kthread+0x305/0x3f0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x40/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
This commit therefore use rq_lock_irqsave/irqrestore() to replace
rq_lock/unlock() in the scx_dump_state().
sched_ext: Fix unsafe locking in the scx_dump_state()
For built with CONFIG_PREEMPT_RT=y kernels, the dump_lock will be converted
sleepable spinlock and not disable-irq, so the following scenarios occur:
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
irq_work/0/27 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&rq->__lock){?...}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x40
{IN-HARDIRQ-W} state was registered at:
lock_acquire+0x1e1/0x510
_raw_spin_lock_nested+0x42/0x80
raw_spin_rq_lock_nested+0x2b/0x40
sched_tick+0xae/0x7b0
update_process_times+0x14c/0x1b0
tick_periodic+0x62/0x1f0
tick_handle_periodic+0x48/0xf0
timer_interrupt+0x55/0x80
__handle_irq_event_percpu+0x20a/0x5c0
handle_irq_event_percpu+0x18/0xc0
handle_irq_event+0xb5/0x150
handle_level_irq+0x220/0x460
__common_interrupt+0xa2/0x1e0
common_interrupt+0xb0/0xd0
asm_common_interrupt+0x2b/0x40
_raw_spin_unlock_irqrestore+0x45/0x80
__setup_irq+0xc34/0x1a30
request_threaded_irq+0x214/0x2f0
hpet_time_init+0x3e/0x60
x86_late_time_init+0x5b/0xb0
start_kernel+0x308/0x410
x86_64_start_reservations+0x1c/0x30
x86_64_start_kernel+0x96/0xa0
common_startup_64+0x13e/0x148
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&rq->__lock);
<Interrupt>
lock(&rq->__lock);
*** DEADLOCK ***
stack backtrace:
CPU: 0 UID: 0 PID: 27 Comm: irq_work/0
Call Trace:
<TASK>
dump_stack_lvl+0x8c/0xd0
dump_stack+0x14/0x20
print_usage_bug+0x42e/0x690
mark_lock.part.44+0x867/0xa70
? __pfx_mark_lock.part.44+0x10/0x10
? string_nocheck+0x19c/0x310
? number+0x739/0x9f0
? __pfx_string_nocheck+0x10/0x10
? __pfx_check_pointer+0x10/0x10
? kvm_sched_clock_read+0x15/0x30
? sched_clock_noinstr+0xd/0x20
? local_clock_noinstr+0x1c/0xe0
__lock_acquire+0xc4b/0x62b0
? __pfx_format_decode+0x10/0x10
? __pfx_string+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
? __pfx_vsnprintf+0x10/0x10
lock_acquire+0x1e1/0x510
? raw_spin_rq_lock_nested+0x2b/0x40
? __pfx_lock_acquire+0x10/0x10
? dump_line+0x12e/0x270
? raw_spin_rq_lock_nested+0x20/0x40
_raw_spin_lock_nested+0x42/0x80
? raw_spin_rq_lock_nested+0x2b/0x40
raw_spin_rq_lock_nested+0x2b/0x40
scx_dump_state+0x3b3/0x1270
? finish_task_switch+0x27e/0x840
scx_ops_error_irq_workfn+0x67/0x80
irq_work_single+0x113/0x260
irq_work_run_list.part.3+0x44/0x70
run_irq_workd+0x6b/0x90
? __pfx_run_irq_workd+0x10/0x10
smpboot_thread_fn+0x529/0x870
? __pfx_smpboot_thread_fn+0x10/0x10
kthread+0x305/0x3f0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x40/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
This commit therefore use rq_lock_irqsave/irqrestore() to replace
rq_lock/unlock() in the scx_dump_state().
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 16 Dec 2025 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix unsafe locking in the scx_dump_state() For built with CONFIG_PREEMPT_RT=y kernels, the dump_lock will be converted sleepable spinlock and not disable-irq, so the following scenarios occur: inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. irq_work/0/27 [HC0[0]:SC0[0]:HE1:SE1] takes: (&rq->__lock){?...}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x40 {IN-HARDIRQ-W} state was registered at: lock_acquire+0x1e1/0x510 _raw_spin_lock_nested+0x42/0x80 raw_spin_rq_lock_nested+0x2b/0x40 sched_tick+0xae/0x7b0 update_process_times+0x14c/0x1b0 tick_periodic+0x62/0x1f0 tick_handle_periodic+0x48/0xf0 timer_interrupt+0x55/0x80 __handle_irq_event_percpu+0x20a/0x5c0 handle_irq_event_percpu+0x18/0xc0 handle_irq_event+0xb5/0x150 handle_level_irq+0x220/0x460 __common_interrupt+0xa2/0x1e0 common_interrupt+0xb0/0xd0 asm_common_interrupt+0x2b/0x40 _raw_spin_unlock_irqrestore+0x45/0x80 __setup_irq+0xc34/0x1a30 request_threaded_irq+0x214/0x2f0 hpet_time_init+0x3e/0x60 x86_late_time_init+0x5b/0xb0 start_kernel+0x308/0x410 x86_64_start_reservations+0x1c/0x30 x86_64_start_kernel+0x96/0xa0 common_startup_64+0x13e/0x148 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&rq->__lock); <Interrupt> lock(&rq->__lock); *** DEADLOCK *** stack backtrace: CPU: 0 UID: 0 PID: 27 Comm: irq_work/0 Call Trace: <TASK> dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 print_usage_bug+0x42e/0x690 mark_lock.part.44+0x867/0xa70 ? __pfx_mark_lock.part.44+0x10/0x10 ? string_nocheck+0x19c/0x310 ? number+0x739/0x9f0 ? __pfx_string_nocheck+0x10/0x10 ? __pfx_check_pointer+0x10/0x10 ? kvm_sched_clock_read+0x15/0x30 ? sched_clock_noinstr+0xd/0x20 ? local_clock_noinstr+0x1c/0xe0 __lock_acquire+0xc4b/0x62b0 ? __pfx_format_decode+0x10/0x10 ? __pfx_string+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 ? __pfx_vsnprintf+0x10/0x10 lock_acquire+0x1e1/0x510 ? raw_spin_rq_lock_nested+0x2b/0x40 ? __pfx_lock_acquire+0x10/0x10 ? dump_line+0x12e/0x270 ? raw_spin_rq_lock_nested+0x20/0x40 _raw_spin_lock_nested+0x42/0x80 ? raw_spin_rq_lock_nested+0x2b/0x40 raw_spin_rq_lock_nested+0x2b/0x40 scx_dump_state+0x3b3/0x1270 ? finish_task_switch+0x27e/0x840 scx_ops_error_irq_workfn+0x67/0x80 irq_work_single+0x113/0x260 irq_work_run_list.part.3+0x44/0x70 run_irq_workd+0x6b/0x90 ? __pfx_run_irq_workd+0x10/0x10 smpboot_thread_fn+0x529/0x870 ? __pfx_smpboot_thread_fn+0x10/0x10 kthread+0x305/0x3f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x40/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> This commit therefore use rq_lock_irqsave/irqrestore() to replace rq_lock/unlock() in the scx_dump_state(). | |
| Title | sched_ext: Fix unsafe locking in the scx_dump_state() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-12-16T13:48:30.376Z
Reserved: 2025-12-16T13:41:40.255Z
Link: CVE-2025-68202
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-12-16T14:15:53.047
Modified: 2025-12-16T14:15:53.047
Link: CVE-2025-68202
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.