When support for PCC Opregion was added, validation of field_obj was missed. Based on the acpi_ev_address_space_dispatch function description, field_obj can be NULL, and also when acpi_ev_address_space_dispatch is called in the acpi_ex_region_read() NULL is passed as field_obj.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 0acf24ad7e10 ("ACPICA: Add support for PCC Opregion special context data") Cc: stable@vger.kernel.org Signed-off-by: George Rurikov grurikov@gmail.com --- drivers/acpi/acpica/evregion.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/acpi/acpica/evregion.c b/drivers/acpi/acpica/evregion.c index cf53b9535f18..03e8b6f186af 100644 --- a/drivers/acpi/acpica/evregion.c +++ b/drivers/acpi/acpica/evregion.c @@ -164,13 +164,17 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj, }
if (region_obj->region.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { - struct acpi_pcc_info *ctx = - handler_desc->address_space.context; - - ctx->internal_buffer = - field_obj->field.internal_pcc_buffer; - ctx->length = (u16)region_obj->region.length; - ctx->subspace_id = (u8)region_obj->region.address; + if (field_obj != NULL) { + struct acpi_pcc_info *ctx = + handler_desc->address_space.context; + + ctx->internal_buffer = + field_obj->field.internal_pcc_buffer; + ctx->length = (u16)region_obj->region.length; + ctx->subspace_id = (u8)region_obj->region.address; + } else { + return_ACPI_STATUS(AE_ERROR); + } }
if (region_obj->region.space_id ==