[1/4] drm: edid: Add bounds checking to CEA 18 byte descriptor parsing

Commit Message

Ville Syrjala Aug. 16, 2012, 2:55 p.m. UTC

From: Ville Syrjälä <[e-mail]>

Make sure we don't access beyond the extension block when parsing CEA
detailed timing descriptors.

Signed-off-by: Ville Syrjälä <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
---
 drivers/gpu/drm/drm_edid.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

Patch

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 5873e48..a346b04 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -551,6 +551,9 @@  cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
 	u8 d = ext[0x02];
 	u8 *det_base = ext + d;
 
+	if (d > 127)
+		return;
+
 	n = (127 - d) / 18;
 	for (i = 0; i < n; i++)
 		cb((struct detailed_timing *)(det_base + 18 * i), closure);