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-rw-r--r--drivers/acpi/acpica/tbinstal.c27
1 files changed, 22 insertions, 5 deletions
diff --git a/drivers/acpi/acpica/tbinstal.c b/drivers/acpi/acpica/tbinstal.c
index 48db0944ce4a..62365f6075dd 100644
--- a/drivers/acpi/acpica/tbinstal.c
+++ b/drivers/acpi/acpica/tbinstal.c
@@ -126,12 +126,29 @@ acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index)
}
/*
- * Originally, we checked the table signature for "SSDT" or "PSDT" here.
- * Next, we added support for OEMx tables, signature "OEM".
- * Valid tables were encountered with a null signature, so we've just
- * given up on validating the signature, since it seems to be a waste
- * of code. The original code was removed (05/2008).
+ * Validate the incoming table signature.
+ *
+ * 1) Originally, we checked the table signature for "SSDT" or "PSDT".
+ * 2) We added support for OEMx tables, signature "OEM".
+ * 3) Valid tables were encountered with a null signature, so we just
+ * gave up on validating the signature, (05/2008).
+ * 4) We encountered non-AML tables such as the MADT, which caused
+ * interpreter errors and kernel faults. So now, we once again allow
+ * only "SSDT", "OEMx", and now, also a null signature. (05/2011).
*/
+ if ((table_desc->pointer->signature[0] != 0x00) &&
+ (!ACPI_COMPARE_NAME(table_desc->pointer->signature, ACPI_SIG_SSDT))
+ && (ACPI_STRNCMP(table_desc->pointer->signature, "OEM", 3))) {
+ ACPI_ERROR((AE_INFO,
+ "Table has invalid signature [%4.4s] (0x%8.8X), must be SSDT or OEMx",
+ acpi_ut_valid_acpi_name(*(u32 *)table_desc->
+ pointer->
+ signature) ? table_desc->
+ pointer->signature : "????",
+ *(u32 *)table_desc->pointer->signature));
+
+ return_ACPI_STATUS(AE_BAD_SIGNATURE);
+ }
(void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);