linux/arch/x86/coco
Alexey Gladkov (Intel) d4fc4d0147 x86/tdx: Fix "in-kernel MMIO" check
TDX only supports kernel-initiated MMIO operations. The handle_mmio()
function checks if the #VE exception occurred in the kernel and rejects
the operation if it did not.

However, userspace can deceive the kernel into performing MMIO on its
behalf. For example, if userspace can point a syscall to an MMIO address,
syscall does get_user() or put_user() on it, triggering MMIO #VE. The
kernel will treat the #VE as in-kernel MMIO.

Ensure that the target MMIO address is within the kernel before decoding
instruction.

Fixes: 31d58c4e55 ("x86/tdx: Handle in-kernel MMIO")
Signed-off-by: Alexey Gladkov (Intel) <legion@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/565a804b80387970460a4ebc67c88d1380f61ad1.1726237595.git.legion%40kernel.org
2024-09-26 09:45:04 -07:00
..
sev x86/sev: Fix __reserved field in sev_config 2024-07-30 10:07:26 +02:00
tdx x86/tdx: Fix "in-kernel MMIO" check 2024-09-26 09:45:04 -07:00
core.c cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup 2024-06-17 17:45:34 +02:00
Makefile x86/sev: Move SEV compilation units 2024-07-11 11:55:58 +02:00