Fix a core dump in mod_cache when it attemtped to store uncopyable

buckets. This happened, for instance, when a file to be cached
contained SSI tags to execute a CGI script (passed as a pipe
bucket). [Paul J. Reder]

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@97058 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/CHANGES b/CHANGES
index 2dc754500e0f2dcb44045ba4c93a12a6a25455b7..83b39ca091e9cfd382544f5f1571d4020b1404dc 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,5 +1,10 @@
 Changes with Apache 2.0.43
 
+  *) Fix a core dump in mod_cache when it attemtped to store uncopyable
+     buckets. This happened, for instance, when a file to be cached
+     contained SSI tags to execute a CGI script (passed as a pipe
+     bucket). [Paul J. Reder]
+
   *) Ensure that output already available is flushed to the network
      when the content-length filter realizes that no new output will
      be available for a while.  This helps some streaming CGIs as

diff --git a/modules/experimental/mod_cache.c b/modules/experimental/mod_cache.c
index 78d34c04c317054794623bf9d3940ff477ac8b79..4402fda646d351af32f649df58d82425da9aaec3 100644 (file)
--- a/modules/experimental/mod_cache.c
+++ b/modules/experimental/mod_cache.c
@@ -679,7 +679,36 @@ static int cache_in_filter(ap_filter_t *f, apr_bucket_brigade *in)
                 }
                 APR_BRIGADE_FOREACH(e, in) {
                     apr_bucket *copy;
-                    apr_bucket_copy(e, &copy);
+                    rv = apr_bucket_copy(e, &copy);
+                    if (rv == APR_ENOTIMPL) {
+                        const char *str;
+                        apr_size_t len;
+
+                        /* This takes care of uncopyable buckets. */
+                        rv = apr_bucket_read(e, &str, &len, APR_BLOCK_READ);
+                        if ((rv == APR_SUCCESS) &&
+                            (cache->saved_size + len <=
+                                        conf->max_streaming_buffer_size)) {
+                            rv = apr_bucket_copy(e, &copy);
+                        }
+
+                        if ((rv != APR_SUCCESS) ||
+                            (cache->saved_size + len >
+                                        conf->max_streaming_buffer_size)){
+                            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
+                                         "cache: not caching streamed response for "
+                                         "%s because length %s", url,
+                                          "> CacheMaxStreamingBuffer");
+
+                            if (cache->saved_brigade != NULL) {
+                                apr_brigade_destroy(cache->saved_brigade);
+                                cache->saved_brigade = NULL;
+                                cache->saved_size = 0;
+                            }
+                            ap_remove_output_filter(f);
+                            return ap_pass_brigade(f->next, in);
+                        }
+                    }
                     APR_BRIGADE_INSERT_TAIL(cache->saved_brigade, copy);
                 }
                 cache->saved_size += size;
@@ -1055,7 +1084,7 @@ static const char *set_max_streaming_buffer(cmd_parms *parms, void *dummy,
                                                   &cache_module);
     val = (apr_off_t)strtol(arg, &err, 10);
     if (*err != 0) {
-        return "CacheMaxStreamingBuffer value must be a percentage";
+        return "CacheMaxStreamingBuffer value must be a number";
     }
     conf->max_streaming_buffer_size = val;
     return NULL;

diff --git a/modules/experimental/mod_mem_cache.c b/modules/experimental/mod_mem_cache.c
index 7b91505005ea9822e2ac945a97a83596d676a246..60d1768c2c36aa82411989465ae5cd3ac6e31f43 100644 (file)
--- a/modules/experimental/mod_mem_cache.c
+++ b/modules/experimental/mod_mem_cache.c
@@ -991,10 +991,10 @@ static apr_status_t write_body(cache_handle_t *h, request_rec *r, apr_bucket_bri
                obj->count+=len;
            }
         }
-        /* This should not happen, but if it does, we are in BIG trouble
+        /* This should not fail, but if it does, we are in BIG trouble
          * cause we just stomped all over the heap.
          */
-        AP_DEBUG_ASSERT(obj->count >= mobj->m_len);
+        AP_DEBUG_ASSERT(obj->count <= mobj->m_len);
     }
     return APR_SUCCESS;
 }