Memory leaks in lwan

[ryancaicse]

The memory block created at Line 125 is leaked in the method parse_listener_prefix.

lwan/src/lib/lwan.c

Lines 125 to 139 in 2f34d6f

 struct lwan_url_map *copy = malloc(sizeof(*copy)); 
  
 if (!copy) 
     lwan_status_critical_perror("Could not copy URL map"); 
  
 memcpy(copy, map, sizeof(*copy)); 
  
 copy->prefix = strdup(prefix ? prefix : copy->prefix); 
 if (!copy->prefix) 
     lwan_status_critical_perror("Could not copy URL prefix"); 
  
 copy->prefix_len = strlen(copy->prefix); 
 lwan_trie_add(t, copy->prefix, copy); 
  
 return copy; 

lwan/src/lib/lwan.c

Lines 400 to 404 in 2f34d6f

     add_url_map(&lwan->url_map_trie, prefix, &url_map); 
  
 out: 
     hash_free(hash); 
     config_close(isolated); 

[L. Pereira]

Where's the memory leak?

…

On Sat, Dec 18, 2021, 18:24 ryancaicse ***@***.***> wrote: The memory block created at Line 125 is leaked in the method parse_listener_prefix. https://github.com/lpereira/lwan/blob/2f34d6ff3fa4cbb4a78e274e09cdf029ebb7c77d/src/lib/lwan.c#L125-L139 https://github.com/lpereira/lwan/blob/2f34d6ff3fa4cbb4a78e274e09cdf029ebb7c77d/src/lib/lwan.c#L400-L404 — Reply to this email directly, view it on GitHub <#324>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAADVGORGGIPD4O65F2LVL3URU64XANCNFSM5KLKZV5A> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[L. Pereira]

There's no memory leak in this function. The memory is now owned by the trie, which will call destroy_urlmap() and free the memory. Unless there's a bug in the trie data structure, of course. Are you using some static analysis tool to find these? Because if you are, these tools can be wrong most of the time, especially when "ownership" is passed around like this and function pointers are called to free the memory.

…

On Sat, Dec 18, 2021, 18:40 L. Pereira ***@***.***> wrote: Where's the memory leak? On Sat, Dec 18, 2021, 18:24 ryancaicse ***@***.***> wrote: > The memory block created at Line 125 is leaked in the method > parse_listener_prefix. > > https://github.com/lpereira/lwan/blob/2f34d6ff3fa4cbb4a78e274e09cdf029ebb7c77d/src/lib/lwan.c#L125-L139 > > https://github.com/lpereira/lwan/blob/2f34d6ff3fa4cbb4a78e274e09cdf029ebb7c77d/src/lib/lwan.c#L400-L404 > > — > Reply to this email directly, view it on GitHub > <#324>, or unsubscribe > <https://github.com/notifications/unsubscribe-auth/AAADVGORGGIPD4O65F2LVL3URU64XANCNFSM5KLKZV5A> > . > Triage notifications on the go with GitHub Mobile for iOS > <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> > or Android > <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. > > You are receiving this because you are subscribed to this thread.Message > ID: ***@***.***> >

[ryancaicse]

@lpereira Sorry, when I take a close look, it seems it's wrong.