diff --git a/drivers/acpi/acpica/psargs.c b/drivers/acpi/acpica/psargs.c index 6f6ae38ec044..87d32fbba0a6 100644 --- a/drivers/acpi/acpica/psargs.c +++ b/drivers/acpi/acpica/psargs.c @@ -48,6 +48,7 @@ acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state) u32 package_length = 0; u32 byte_count; u8 byte_zero_mask = 0x3F; /* Default [0:5] */ + u32 remaining; ACPI_FUNCTION_TRACE(ps_get_next_package_length); @@ -55,7 +56,23 @@ acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state) * Byte 0 bits [6:7] contain the number of additional bytes * used to encode the package length, either 0,1,2, or 3 */ + + /* Check if we have at least one byte to read */ + remaining = (u32)ACPI_PTR_DIFF(parser_state->aml_end, aml); + if (remaining == 0) { + return_UINT32(0); + } + byte_count = (aml[0] >> 6); + + /* Validate byte_count and ensure we have enough bytes to read */ + if (byte_count >= remaining) { + + /* Clamp to available bytes and advance to end */ + parser_state->aml = parser_state->aml_end; + return_UINT32(0); + } + parser_state->aml += ((acpi_size)byte_count + 1); /* Get bytes 3, 2, 1 as needed */