Description

In the Linux kernel, the following vulnerability has been resolved: PCI: Add missing bridge lock to pci_bus_lock() One of the true positives that the cfg_access_lock lockdep effort identified is this sequence: WARNING: CPU: 14 PID: 1 at drivers/pci/pci.c:4886 pci_bridge_secondary_bus_reset+0x5d/0x70 RIP: 0010:pci_bridge_secondary_bus_reset+0x5d/0x70 Call Trace: ? __warn+0x8c/0x190 ? pci_bridge_secondary_bus_reset+0x5d/0x70 ? report_bug+0x1f8/0x200 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? pci_bridge_secondary_bus_reset+0x5d/0x70 pci_reset_bus+0x1d8/0x270 vmd_probe+0x778/0xa10 pci_device_probe+0x95/0x120 Where pci_reset_bus() users are triggering unlocked secondary bus resets. Ironically pci_bus_reset(), several calls down from pci_reset_bus(), uses pci_bus_lock() before issuing the reset which locks everything *but* the bridge itself. For the same motivation as adding: bridge = pci_upstream_bridge(dev); if (bridge) pci_dev_lock(bridge); to pci_reset_function() for the "bus" and "cxl_bus" reset cases, add pci_dev_lock() for @bus->self to pci_bus_lock(). [bhelgaas: squash in recursive locking deadlock fix from Keith Busch: https://lore.kernel.org/r/[email protected]]

Severity MEDIUM

CVSS Score 5.5

CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE CWE-667

Public Exploit ✅ No

Source NVD

Published 2024-09-18

Updated 2026-06-02

Modified 2026-05-12

Fix URL https://git.kernel.org/stable/c/04e85a3285b0e5c5af6fd2c0fd6e95ffecc01945

Software	From version	Fixed in
linux-kernel	6.7	6.10.10