HTTP/3: fixed overflow in prefixed integer parser.

Previously, the expression (ch & 0x7f) was promoted to a signed integer.
Depending on the platform, the size of this integer could be less than 8 bytes,
leading to overflow when handling the higher bits of the result.  Also, sign
bit of this integer could be replicated when adding to the 64-bit st->value.

diff --git a/src/http/v3/ngx_http_v3_parse.c b/src/http/v3/ngx_http_v3_parse.c
index da9826ced3921cac1464ab865a7536f68c1e946f..bb8d7329678195118150a14b99ad5512b0f5281b 100644 (file)
--- a/src/http/v3/ngx_http_v3_parse.c
+++ b/src/http/v3/ngx_http_v3_parse.c
@@ -118,7 +118,7 @@ ngx_http_v3_parse_prefix_int(ngx_connection_t *c,
 
     case sw_value:
 
-        st->value += (ch & 0x7f) << st->shift;
+        st->value += (uint64_t) (ch & 0x7f) << st->shift;
         if (ch & 0x80) {
             st->shift += 7;
             break;