mod_log-any/3397: potential DOS, and an irritating, difficult to track error

[Tani Hosokawa <un...@riverstyx.net>]

>Number:         3397
>Category:       mod_log-any
>Synopsis:       potential DOS, and an irritating, difficult to track error
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Fri Nov 13 00:20:01 PST 1998
>Last-Modified:
>Originator:     unknown@riverstyx.net
>Organization:
apache
>Release:        all
>Environment:
Linux, presumably all Unices, dunno about NT.
>Description:
If you've got a log set up to a directory that doesn't exist 
(ie /home/unknown/logs/transfer_log) and that directory doesn't exist, Apache 
will quietly not start.  Nothing gets output to the error log even though there 
is a piece of code that's supposed to dump an error out:

        char *fname = ap_server_root_relative(p, cls->fname);
        if ((cls->log_fd = ap_popenf(p, fname, xfer_flags, xfer_mode)) < 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR, s,
                         "httpd: could not open transfer log file %s.", fname);
            exit(1);

However, it just goes into the nether.  Ya get nuthin'.  I dunno if this is 
because the process that's supposed to be logging gets killed before it gets
a chance to write, but hey, it still causes me problems.
>How-To-Repeat:
Just set a log to a directory that doesn't exist.  I've only tried it inside a
VirtualHost directive, which may affect it.
>Fix:
This is a pretty easy way to fix it... stderr is usually by this point
redirected to the error log, so I put an fprintf in right after the ap_log_error
call, and that does end up going into the error log.

        char *fname = ap_server_root_relative(p, cls->fname);
        if ((cls->log_fd = ap_popenf(p, fname, xfer_flags, xfer_mode)) < 0) {
            ap_log_error(APLOG_MARK, APLOG_ERR, s,
                         "httpd: could not open transfer log file %s.", fname);
            fprintf(stderr, "httpd: could not open transfer log file %s.\n", fname);
            exit(1);
>Audit-Trail:
>Unformatted:
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