[Mesa-dev] [PATCH] intel/decoder: fix the possible out of bounds group_iter

[Andrii Simiklit]

The "gen_group_get_length" function can return a negative value
and it can lead to the out of bounds group_iter.

Signed-off-by: Andrii Simiklit <andrii.simiklit at globallogic.com>
---
 src/intel/common/gen_decoder.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/intel/common/gen_decoder.c b/src/intel/common/gen_decoder.c
index ec0a486..f09bd87 100644
--- a/src/intel/common/gen_decoder.c
+++ b/src/intel/common/gen_decoder.c
@@ -803,8 +803,10 @@ static bool
 iter_more_groups(const struct gen_field_iterator *iter)
 {
    if (iter->group->variable) {
-      return iter_group_offset_bits(iter, iter->group_iter + 1) <
-              (gen_group_get_length(iter->group, iter->p) * 32);
+      const int length = gen_group_get_length(iter->group, iter->p);
+      return length > 0 &&
+             iter_group_offset_bits(iter, iter->group_iter + 1) <
+              (length * 32);
    } else {
       return (iter->group_iter + 1) < iter->group->group_count ||
          iter->group->next != NULL;
-- 
2.7.4