From cb7cf772d83d2d4e6995c5bb9e0fb59aea8f7080 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Fri, 26 May 2017 17:40:02 +0100 Subject: [PATCH] ARM64/ACPI: Fix BAD_MADT_GICC_ENTRY() macro implementation The BAD_MADT_GICC_ENTRY() macro checks if a GICC MADT entry passes muster from an ACPI specification standpoint. Current macro detects the MADT GICC entry length through ACPI firmware version (it changed from 76 to 80 bytes in the transition from ACPI 5.1 to ACPI 6.0 specification) but always uses (erroneously) the ACPICA (latest) struct (ie struct acpi_madt_generic_interrupt - that is 80-bytes long) length to check if the current GICC entry memory record exceeds the MADT table end in memory as defined by the MADT table header itself, which may result in false negatives depending on the ACPI firmware version and how the MADT entries are laid out in memory (ie on ACPI 5.1 firmware MADT GICC entries are 76 bytes long, so by adding 80 to a GICC entry start address in memory the resulting address may well be past the actual MADT end, triggering a false negative). Fix the BAD_MADT_GICC_ENTRY() macro by reshuffling the condition checks and update them to always use the firmware version specific MADT GICC entry length in order to carry out boundary checks. Fixes: b6cfb277378e ("ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro") Reported-by: Julien Grall Acked-by: Will Deacon Acked-by: Marc Zyngier Signed-off-by: Lorenzo Pieralisi Cc: Julien Grall Cc: Hanjun Guo Cc: Al Stone Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/acpi.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 0e99978da3f0..59cca1d6ec54 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -23,9 +23,9 @@ #define ACPI_MADT_GICC_LENGTH \ (acpi_gbl_FADT.header.revision < 6 ? 76 : 80) -#define BAD_MADT_GICC_ENTRY(entry, end) \ - (!(entry) || (unsigned long)(entry) + sizeof(*(entry)) > (end) || \ - (entry)->header.length != ACPI_MADT_GICC_LENGTH) +#define BAD_MADT_GICC_ENTRY(entry, end) \ + (!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \ + (unsigned long)(entry) + ACPI_MADT_GICC_LENGTH > (end)) /* Basic configuration for ACPI */ #ifdef CONFIG_ACPI -- 2.20.1