CVE-2026-74468

Description

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").

Gravité et risque d'exploitation

CVE-2026-74468 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.22 %, ce qui la place devant 11.7 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <3.2, <=6.12.*, 38eb18a6f92da886fc1af509d25e8f7a49e23d9a, <ff050589a21967883bb55f6dba42568f8367ad4a, 0, <935e6872db7faecfbe1a10b3f5d97a62fdff5ec9, <=7.1.*, <a02b8950d619123da64f69b70fe1dadef217dfe4, <466ab0c41d5f54f71cee60619d07c4abd0ffd2cd, 5.15.216, 6.12.103, <=5.10.*, <=6.6.*, <16da33cb36e663b6967112185e11d00ce8ff957c, <c0a4ec89fc26e4b679b04f1002c503cb2529acdc, 6.1.183, <98f292cb6d01487d17988d9fd4e19c13e7adb156, <=6.18.*, 3.2, <=*, <=5.15.*, 7.1.8, 6.18.44, 6.6.151, 5.10.265, 7.2, <efc76a3f5353dd33a2e2ad48200cd4a18de30a0d) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/efc76a3f5353dd33a2e2ad48200cd4a18de30a0d
• https://git.kernel.org/stable/c/935e6872db7faecfbe1a10b3f5d97a62fdff5ec9
• https://git.kernel.org/stable/c/98f292cb6d01487d17988d9fd4e19c13e7adb156
• https://git.kernel.org/stable/c/16da33cb36e663b6967112185e11d00ce8ff957c
• https://git.kernel.org/stable/c/ff050589a21967883bb55f6dba42568f8367ad4a
• https://git.kernel.org/stable/c/466ab0c41d5f54f71cee60619d07c4abd0ffd2cd
• https://git.kernel.org/stable/c/c0a4ec89fc26e4b679b04f1002c503cb2529acdc
• https://git.kernel.org/stable/c/a02b8950d619123da64f69b70fe1dadef217dfe4