Executive brief
A vulnerability in the Linux kernel's Microsoft Azure Network Adapter (MANA) driver could cause a system crash (NULL pointer dereference) under specific virtualization scenarios, such as nested KVM or VFIO passthrough. This occurs when the system attempts to create debug directories for virtual network interfaces using invalid memory references. While primarily affecting system stability and availability, it could be used to trigger a denial-of-service on affected hosts.
Technical details
A vulnerability exists in the MANA (Microsoft Azure Network Adapter) driver within the Linux kernel's gdma_main.c component. The driver previously used pci_slot_name() to name debugfs directories for Virtual Functions (VFs); however, pdev->slot can be NULL in environments like generic VFIO passthrough or nested KVM, leading to a NULL pointer dereference. Additionally, the driver used a hardcoded '0' for Physical Functions (PFs), causing naming collisions and -EEXIST errors in multi-PF configurations. The fix replaces these calls with pci_name(pdev), which provides a unique and always-valid BDF address. This issue is reachable locally during device probing or driver initialization.
Affected products
- Linux Linux Kernel 6.13, 6.18.33, 7.0.10, 7.1
Timeline
- 2026-04-12: patched: Initial fix committed to mainline kernel.
- 2026-06-26: disclosed: CVE published.