CVE-2026-97441ata: ahci: fail probe if BAR too small for claimed ports

Official 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]

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/533a08ea11217100cec7a0ed903cb9b9c892d6f1
• https://git.kernel.org/stable/c/c717b20100ef8cd06b5237af70ea2cb692e058ce
• https://git.kernel.org/stable/c/ff0ab535f8febbd32afa5832f8d2d9b06a8d5060
• https://git.kernel.org/stable/c/6d29b91164424256a759ddabc8f2de1ae09bd3f1
• https://git.kernel.org/stable/c/df262c828b616450eb351349e91c63447551bd01
• https://git.kernel.org/stable/c/f2e291043c37a896d7f9797e25a356dceb030177
• https://git.kernel.org/stable/c/c4086c6e1af757e1ff26fa2d2926b3ec0195de79