Описание
In the Linux kernel, the following vulnerability has been resolved:
gpio: pch: use raw_spinlock_t for the register lock
pch_irq_type() is registered as the irq_chip .irq_set_type callback and
takes chip->spinlock with spin_lock_irqsave(). This callback is reached
from __setup_irq() -> __irq_set_trigger() -> chip->irq_set_type() while
the caller holds desc->lock, a raw_spinlock_t, with hardirqs disabled.
That context is not sleepable, but on PREEMPT_RT a regular spinlock_t is
an rtmutex-backed sleeping lock, so acquiring it there is invalid.
This was confirmed on a PREEMPT_RT kernel with lockdep
(PROVE_RAW_LOCK_NESTING and DEBUG_ATOMIC_SLEEP). A grounded PoC mirrored
pch_irq_type()'s locking and drove it through the real genirq carrier
irq_set_irq_type() -> __irq_set_trigger() -> chip->irq_set_type(), i.e.
the same __irq_set_trigger() edge that __setup_irq() takes for a
requested IRQ. With the original spin_lock_irqsave() edge lockdep
reported an invalid wait context, immediately followed by:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 95, name: insmod
hardirqs last disabled at (3784): _raw_spin_lock_irqsave+0x4f/0x60
rt_spin_lock+0x3a/0x1c0
repro_irq_set_type+0x64/0xa0 [pch_repro]
__irq_set_trigger+0x69/0x140
irq_set_irq_type+0x78/0xd0
Switching the mirrored lock to raw_spinlock_t made both splats go away.
Convert the register lock to raw_spinlock_t. The same lock also
serializes the GPIO direction/value callbacks and the suspend/resume
register save/restore, but all of those critical sections only perform
MMIO register accesses (ioread32()/iowrite32()) and
irq_set_handler_locked(); none of them contain sleepable operations.
Keeping this register lock non-sleeping is therefore appropriate for the
irqchip callbacks and does not change the GPIO-side locking contract.
This is the same class of issue and fix as recently addressed for other
GPIO controllers, e.g. commit 286533cb14a3 ("gpio: sch: use raw_spinlock_t
in the irq startup path") and commit 90f0109019e6 ("gpio: eic-sprd: use
raw_spinlock_t in the irq startup path").
A flaw was found in the Linux kernel's GPIO PCH driver. On systems configured with PREEMPT_RT, a local attacker could trigger a specific interrupt handler (pch_irq_type()) in a non-sleepable context. This improper use of a spinlock, which attempts to acquire a sleeping lock in an atomic context, can lead to a kernel panic and system instability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: gpio: pch: use raw_spinlock_t for the register lock pch_irq_type() is registered as the irq_chip .irq_set_type callback and takes chip->spinlock with spin_lock_irqsave(). This callback is reached from __setup_irq() -> __irq_set_trigger() -> chip->irq_set_type() while the caller holds desc->lock, a raw_spinlock_t, with hardirqs disabled. That context is not sleepable, but on PREEMPT_RT a regular spinlock_t is an rtmutex-backed sleeping lock, so acquiring it there is invalid. This was confirmed on a PREEMPT_RT kernel with lockdep (PROVE_RAW_LOCK_NESTING and DEBUG_ATOMIC_SLEEP). A grounded PoC mirrored pch_irq_type()'s locking and drove it through the real genirq carrier irq_set_irq_type() -> __irq_set_trigger() -> chip->irq_set_type(), i.e. the same __irq_set_trigger() edge that __setup_irq() takes for a requested IRQ. With the original spin_lock_irqsave() edge lockdep reported an invalid wait context, immediately ...
In the Linux kernel, the following vulnerability has been resolved: gpio: pch: use raw_spinlock_t for the register lock pch_irq_type() is registered as the irq_chip .irq_set_type callback and takes chip->spinlock with spin_lock_irqsave(). This callback is reached from __setup_irq() -> __irq_set_trigger() -> chip->irq_set_type() while the caller holds desc->lock, a raw_spinlock_t, with hardirqs disabled. That context is not sleepable, but on PREEMPT_RT a regular spinlock_t is an rtmutex-backed sleeping lock, so acquiring it there is invalid. This was confirmed on a PREEMPT_RT kernel with lockdep (PROVE_RAW_LOCK_NESTING and DEBUG_ATOMIC_SLEEP). A grounded PoC mirrored pch_irq_type()'s locking and drove it through the real genirq carrier irq_set_irq_type() -> __irq_set_trigger() -> chip->irq_set_type(), i.e. the same __irq_set_trigger() edge that __setup_irq() takes for a requested IRQ. With the original spin_lock_irqsave() edge lockdep reported an invalid wait context, immediately
In the Linux kernel, the following vulnerability has been resolved: g ...
In the Linux kernel, the following vulnerability has been resolved: gpio: pch: use raw_spinlock_t for the register lock pch_irq_type() is registered as the irq_chip .irq_set_type callback and takes chip->spinlock with spin_lock_irqsave(). This callback is reached from __setup_irq() -> __irq_set_trigger() -> chip->irq_set_type() while the caller holds desc->lock, a raw_spinlock_t, with hardirqs disabled. That context is not sleepable, but on PREEMPT_RT a regular spinlock_t is an rtmutex-backed sleeping lock, so acquiring it there is invalid. This was confirmed on a PREEMPT_RT kernel with lockdep (PROVE_RAW_LOCK_NESTING and DEBUG_ATOMIC_SLEEP). A grounded PoC mirrored pch_irq_type()'s locking and drove it through the real genirq carrier irq_set_irq_type() -> __irq_set_trigger() -> chip->irq_set_type(), i.e. the same __irq_set_trigger() edge that __setup_irq() takes for a requested IRQ. With the original spin_lock_irqsave() edge lockdep reported an invalid wait context, immediate...
EPSS
5.5 Medium
CVSS3