From: Linn Crosetto Date: Wed, 16 Mar 2016 14:43:33 -0600 Subject: [17/18] acpi: Disable APEI error injection if securelevel is set Origin: https://github.com/mjg59/linux/commit/d7a6be58edc01b1c66ecd8fcc91236bfbce0a420 ACPI provides an error injection mechanism, EINJ, for debugging and testing the ACPI Platform Error Interface (APEI) and other RAS features. If supported by the firmware, ACPI specification 5.0 and later provide for a way to specify a physical memory address to which to inject the error. Injecting errors through EINJ can produce errors which to the platform are indistinguishable from real hardware errors. This can have undesirable side-effects, such as causing the platform to mark hardware as needing replacement. While it does not provide a method to load unauthenticated privileged code, the effect of these errors may persist across reboots and affect trust in the underlying hardware, so disable error injection through EINJ if securelevel is set. Signed-off-by: Linn Crosetto --- drivers/acpi/apei/einj.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/acpi/apei/einj.c +++ b/drivers/acpi/apei/einj.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include "apei-internal.h" @@ -521,6 +522,9 @@ static int einj_error_inject(u32 type, u int rc; unsigned long pfn; + if (get_securelevel() > 0) + return -EPERM; + /* If user manually set "flags", make sure it is legal */ if (flags && (flags & ~(SETWA_FLAGS_APICID|SETWA_FLAGS_MEM|SETWA_FLAGS_PCIE_SBDF)))