From: Bob Moore <robert.moore@xxxxxxxxx> ACPICA commit ba5020b2dbe1538e4ccd7ac2dfd8843a690c007f This change enhances the detection of resource descriptors within a buffer object. For the end_tag opcode, the second byte is defined to be either a checksum or zero. All known ASL compilers insert a zero for this byte. The disassembler now ensures this byte is zero before deciding that a buffer should be disassembled to a resource descriptor. This helps eliminate incorrect decisions when attempting to disassemble a buffer to a resource descriptor. Link: https://github.com/acpica/acpica/commit/ba5020b2 Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx> --- drivers/acpi/acpica/utresrc.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/acpi/acpica/utresrc.c b/drivers/acpi/acpica/utresrc.c index ff096d9..e0587c8 100644 --- a/drivers/acpi/acpica/utresrc.c +++ b/drivers/acpi/acpica/utresrc.c @@ -474,6 +474,15 @@ acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state, return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG); } + /* + * The end_tag opcode must be followed by a zero byte. + * Although this byte is technically defined to be a checksum, + * in practice, all ASL compilers set this byte to zero. + */ + if (*(aml + 1) != 0) { + return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG); + } + /* Return the pointer to the end_tag if requested */ if (!user_function) { -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
