Mercurial > hg > nginx
diff auto/summary @ 6627:ad736705a744
HTTP/2: avoid left-shifting signed integer into the sign bit.
On non-aligned platforms, properly cast argument before left-shifting it in
ngx_http_v2_parse_uint32 that is used with u_char. Otherwise it propagates
to int to hold the value and can step over the sign bit. Usually, on known
compilers, this results in negation. Furthermore, a subsequent store into a
wider type, that is ngx_uint_t on 64-bit platforms, results in sign-extension.
In practice, this can be observed in debug log as a very large exclusive bit
value, when client sent PRIORITY frame with exclusive bit set:
: *14 http2 PRIORITY frame sid:5 on 1 excl:8589934591 weight:17
Found with UndefinedBehaviorSanitizer.
author | Sergey Kandaurov <pluknet@nginx.com> |
---|---|
date | Thu, 07 Jul 2016 21:03:21 +0300 |
parents | 9eefb38f0005 |
children | 0b5f12d5c531 |