apparmor: add missing id bounds check on dfa verification
Signed-off-by: John Johansen <john.johansen@canonical.com>
diff --git a/security/apparmor/include/match.h b/security/apparmor/include/match.h
index 001c43a..a1c04fe 100644
--- a/security/apparmor/include/match.h
+++ b/security/apparmor/include/match.h
@@ -62,6 +62,7 @@
#define YYTD_ID_ACCEPT2 6
#define YYTD_ID_NXT 7
#define YYTD_ID_TSIZE 8
+#define YYTD_ID_MAX 8
#define YYTD_DATA8 1
#define YYTD_DATA16 2
diff --git a/security/apparmor/match.c b/security/apparmor/match.c
index 727eb42..f9f57c6 100644
--- a/security/apparmor/match.c
+++ b/security/apparmor/match.c
@@ -47,6 +47,8 @@
* it every time we use td_id as an index
*/
th.td_id = be16_to_cpu(*(u16 *) (blob)) - 1;
+ if (th.td_id > YYTD_ID_MAX)
+ goto out;
th.td_flags = be16_to_cpu(*(u16 *) (blob + 2));
th.td_lolen = be32_to_cpu(*(u32 *) (blob + 8));
blob += sizeof(struct table_header);