From: Mario Limonciello <mario.limonciello@xxxxxxx> An HP Pavilion Aero Laptop 13-be0xxx/8916 has an ACPI EDID, but using it is causing corruption. It's got illogical values of not specifying a digital interface. Sanity check the ACPI EDID to avoid tripping such problems. Suggested-by: Tobias Jakobi <tjakobi@xxxxxxxxxxxxxxxxxxxxx> Reported-and-tested-by: Chris Bainbridge <chris.bainbridge@xxxxxxxxx> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3782 Fixes: c6a837088bed ("drm/amd/display: Fetch the EDID from _DDC if available for eDP") Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> --- .../drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index b0fea0856866d..6cbbb71d752be 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -907,14 +907,14 @@ dm_helpers_probe_acpi_edid(void *data, u8 *buf, unsigned int block, size_t len) struct drm_connector *connector = data; struct acpi_device *acpidev = ACPI_COMPANION(connector->dev->dev); unsigned char start = block * EDID_LENGTH; - void *edid; + struct edid *edid; int r; if (!acpidev) return -ENODEV; /* fetch the entire edid from BIOS */ - r = acpi_video_get_edid(acpidev, ACPI_VIDEO_DISPLAY_LCD, -1, &edid); + r = acpi_video_get_edid(acpidev, ACPI_VIDEO_DISPLAY_LCD, -1, (void *)&edid); if (r < 0) { drm_dbg(connector->dev, "Failed to get EDID from ACPI: %d\n", r); return r; @@ -924,7 +924,14 @@ dm_helpers_probe_acpi_edid(void *data, u8 *buf, unsigned int block, size_t len) goto cleanup; } - memcpy(buf, edid + start, len); + /* sanity check */ + if (edid->revision < 4 || !(edid->input & DRM_EDID_INPUT_DIGITAL) || + (edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_UNDEF) { + r = -EINVAL; + goto cleanup; + } + + memcpy(buf, (void *)edid + start, len); r = 0; cleanup: -- 2.43.0
