Resolver: fixed possible use-after-free while resolving PTR. Previously, if a response to the PTR request was cached, and ngx_resolver_dup() failed to allocate memory for the resulting name, then the original node was freed but left in expire_queue. A subsequent address resolving would end up in a use-after-free memory access of the node either in ngx_resolver_expire() or ngx_resolver_process_ptr(), when accessing it through expire_queue. The fix is to leave the resolver node intact.

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


ngx_include="unistd.h";      . auto/include
ngx_include="inttypes.h";    . auto/include
ngx_include="limits.h";      . auto/include
ngx_include="sys/filio.h";   . auto/include
ngx_include="sys/param.h";   . auto/include
ngx_include="sys/mount.h";   . auto/include
ngx_include="sys/statvfs.h"; . auto/include
ngx_include="crypt.h";       . auto/include