1 files changed, 5 insertions, 2 deletions

diff --git a/lib/asn1_decoder.c b/lib/asn1_decoder.c
index 0bd8a611eb83..1ef0cec38d78 100644
--- a/lib/asn1_decoder.c
+++ b/lib/asn1_decoder.c
@@ -228,7 +228,7 @@ next_op:
                 hdr = 2;
 
                 /* Extract a tag from the data */
-                if (unlikely(dp >= datalen - 1))
+                if (unlikely(datalen - dp < 2))
                         goto data_overrun_error;
                 tag = data[dp++];
                 if (unlikely((tag & 0x1f) == ASN1_LONG_TAG))
@@ -274,7 +274,7 @@ next_op:
                                 int n = len - 0x80;
                                 if (unlikely(n > 2))
                                         goto length_too_long;
-                                if (unlikely(dp >= datalen - n))
+                                if (unlikely(n > datalen - dp))
                                         goto data_overrun_error;
                                 hdr += n;
                                 for (len = 0; n > 0; n--) {
@@ -284,6 +284,9 @@ next_op:
                                 if (unlikely(len > datalen - dp))
                                         goto data_overrun_error;
                         }
+                } else {
+                        if (unlikely(len > datalen - dp))
+                                goto data_overrun_error;
                 }
 
                 if (flags & FLAG_CONS) {