Hello! On Fri, Dec 01, 2017 at 09:42:37PM -0200, Ranier Vf wrote:
> Coverity report dereference after null check in > /src/http/ngx_http_upstream.c > > CID 400852 (#1 of 1): Dereference after null check (FORWARD_NULL)22. > var_deref_op: Dereferencing null pointer u->pipe. > > line 4356: ngx_http_file_cache_free(r->cache, u->pipe->temp_file); > > Required add check u->pipe? It's complicated. Simply adding a check in a particular place is certainly wrong, as r->cache is only expected to exist only if u->pipe exists as well. On the other hand, in theory it is possible for r->cache to be not in sync with "u" in a very specific case of filter finalization (combined with caching, and also combined with error_page redirection to a different location with upstream), when "u" comes from an old upstream connection, and r->cache was already updated to work with a new one. Additional u->pipe checks won't help here though, as almost every thing done with r->cache in such a case is likely wrong. One of the possible fixes I've suggested several years ago is to move r->cache to upstream structure, so the old "u" will be self-consistent, though Igor disagree with such approach. Not sure there are other good solutions though. The problem is mostly theoretical though, as all practical cases work fine. -- Maxim Dounin http://mdounin.ru/ _______________________________________________ nginx-devel mailing list [email protected] http://mailman.nginx.org/mailman/listinfo/nginx-devel
