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Exit more gracefully if uri length is zero #173

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Exit more gracefully if uri length is zero #173

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2 changes: 2 additions & 0 deletions CHANGES
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Original file line number Diff line number Diff line change
@@ -1,6 +1,8 @@
v1.0.x - YYYY-MMM-DD (To be released)
-------------------------------------

- Exit more gracefully if uri length is zero
[@martinhsv]
- Fixed obtaining of server_addr
[Issue #167, #168 - @defanator]
- Avoid processing of subrequests initiated by the error_page
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4 changes: 4 additions & 0 deletions src/ngx_http_modsecurity_rewrite.c
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Expand Up @@ -150,6 +150,10 @@ ngx_http_modsecurity_rewrite_handler(ngx_http_request_t *r)
if (n_uri == (char*)-1 || n_method == (char*)-1) {
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I'm not sure whether the better way is to change this check in a way like if (n_uri == NULL || n_method == NULL)?

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Assuming we want to leave the utility function ngx_str_to_char unchanged, it effectively has two different error return values: NULL, and (char *)-1. In that case it's useful to retain the existing line 150 check ... but then in addition also check for n_uri == NULL (the error use case that was occurring in owasp-modsecurity/ModSecurity#2216). We could of course also add a check for n_method==NULL, but I was focussed solely on improving the error handling for the case that we actually saw.

return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
if (n_uri == NULL) {
dd("uri is of length zero");
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
old_pool = ngx_http_modsecurity_pcre_malloc_init(r->pool);
msc_process_uri(ctx->modsec_transaction, n_uri, n_method, http_version);
ngx_http_modsecurity_pcre_malloc_done(old_pool);
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