Concurrent logging buggy without /etc/passwd

[azurit]

Describe the bug

When running in environment without /etc/passwd (or without access to it), concurrent logging is very buggy as it cannot find user names, the uninitialized/empty memory data is used as names of files in /tmp and in SecAuditLogStorageDir. The problem is in file apache2/msc_logging.c, function construct_auditlog_filename, lines:

char *username;
...
apr_uid_name_get(&username, uid, mp);

The return value of function apr_uid_name_get should be checked and if getting user name failed, something other should be used (i suggest UID).

Server (please complete the following information):

• ModSecurity version (and connector): 2.9.3
• WebServer: apache 2.4.25 running in very strict environment done using apparmor
• OS (and distro): Debian Stretch

[azurit]

Also file apache2/persist_dbm.c, functions collection_retrieve_ex, collection_store and collections_remove_stale.

[zimmerle]

Hi @azurit,

Thank you for the report, I am liking this issue to #2046 as it seems to be related.

[martinhsv]

Closing per duplicate previously cited.