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authorChris Wilson <chris@chris-wilson.co.uk>2014-04-18 18:04:23 -0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2014-05-05 09:08:58 +0200
commitd1f13fd261f4490b3b69c1da87711fd3813c2a9f (patch)
treec75ef06becb199d9aeaada1c3bd7b27c43fe64fb /drivers/gpu/drm
parentc6df39b5ea6342323a42edfbeeca0a28c643d7ae (diff)
drm/i915: Validate BDB section before reading
Make sure that the whole BDB section is within the MMIO region prior to accessing it contents. That we don't read outside of the secion is left up to the individual section parsers. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com> Reviewed-by: Shobhit Kumar <shobhit.kumar@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/i915/intel_bios.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index fba9efd09e8..148d8a786c8 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -49,13 +49,19 @@ find_section(struct bdb_header *bdb, int section_id)
total = bdb->bdb_size;
/* walk the sections looking for section_id */
- while (index < total) {
+ while (index + 3 < total) {
current_id = *(base + index);
index++;
+
current_size = *((u16 *)(base + index));
index += 2;
+
+ if (index + current_size > total)
+ return NULL;
+
if (current_id == section_id)
return base + index;
+
index += current_size;
}