From: Antonio Quartulli Date: Thu, 31 Oct 2024 15:28:48 +0000 (+0100) Subject: drm/amdgpu: prevent NULL pointer dereference if ATIF is not supported X-Git-Tag: microblaze-v6.16~490^2~9^2~21 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=91c9e221fe2553edf2db71627d8453f083de87a1;p=linux-2.6-microblaze.git drm/amdgpu: prevent NULL pointer dereference if ATIF is not supported acpi_evaluate_object() may return AE_NOT_FOUND (failure), which would result in dereferencing buffer.pointer (obj) while being NULL. Although this case may be unrealistic for the current code, it is still better to protect against possible bugs. Bail out also when status is AE_NOT_FOUND. This fixes 1 FORWARD_NULL issue reported by Coverity Report: CID 1600951: Null pointer dereferences (FORWARD_NULL) Signed-off-by: Antonio Quartulli Fixes: c9b7c809b89f ("drm/amd: Guard against bad data for ATIF ACPI method") Reviewed-by: Mario Limonciello Link: https://lore.kernel.org/r/20241031152848.4716-1-antonio@mandelbit.com Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c index cce85389427f..b8d4e07d2043 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c @@ -172,8 +172,8 @@ static union acpi_object *amdgpu_atif_call(struct amdgpu_atif *atif, &buffer); obj = (union acpi_object *)buffer.pointer; - /* Fail if calling the method fails and ATIF is supported */ - if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { + /* Fail if calling the method fails */ + if (ACPI_FAILURE(status)) { DRM_DEBUG_DRIVER("failed to evaluate ATIF got %s\n", acpi_format_exception(status)); kfree(obj);