Description
In the Linux kernel, the following vulnerability has been resolved:
ata: ahci: fail probe if BAR too small for claimed ports
When an AHCI controller is disabled in BIOS, its HOST_CAP register may contain a bogus value, e.g. 0xFFFFFFFF.
Since CAP.NP (Number of Ports) is a zeroes based 5-bit register field, a value of 0x1f means 32 ports. If CAP.NP claims more ports than can physically fit within the mapped BAR region, accessing port registers beyond the BAR boundary causes a kernel panic.
Add validation in ahci_init_one() to check that the BAR size is sufficient for the number of ports claimed in CAP.NP. The check calculates the required MMIO size as:
required_size = 0x100 (global registers) + max_ports * 0x80
If required_size exceeds the actual BAR size, the probe fails with -ENODEV, preventing the panic and providing a clear error message.
[cassel: commit log]
Metrics
No CVSS score has been published yet.
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
No affected versions have been published.
Timeline
- Published
- Sep 24, 2026
- Last modified
- Oct 3, 2026
- NVD status
- Received