From aa6358430aa9707d1397c05bd373b1784cd08278 Mon Sep 17 00:00:00 2001 From: Antonio Quartulli Date: Thu, 31 Oct 2024 16:28:48 +0100 Subject: [PATCH] drm/amdgpu: prevent NULL pointer dereference if ATIF is not supported commit a6dd15981c03f2cdc9a351a278f09b5479d53d2e upstream. 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 (cherry picked from commit 91c9e221fe2553edf2db71627d8453f083de87a1) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c index 77886e79d..0a9f00a3e 100755 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c @@ -112,8 +112,8 @@ 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);