CVE-2025-23161

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type

The access to the PCI config space via pci_ops::read and pci_ops::write is

a low-level hardware access. The functions can be accessed with disabled

interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this

purpose.

A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be

acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in

the same context as the pci_lock.

Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with

interrupts disabled.

This was reported as:

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48

Call Trace:

rt_spin_lock+0x4e/0x130

vmd_pci_read+0x8d/0x100 [vmd]

pci_user_read_config_byte+0x6f/0xe0

pci_read_config+0xfe/0x290

sysfs_kf_bin_read+0x68/0x90

[bigeasy: reword commit message]

Tested-off-by: Luis Claudio R. Goncalves <[email protected]

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References