bugConcurrent Versions System - Bugs: bug #36276, Potential problem in...


bug #36276: Potential problem in parse_config() which may leak file descriptor

Submitted by:  None
Submitted on:  Mon 23 Apr 2012 08:26:36 PM UTC  
Category:  Bug Report Severity:  3 - Normal
Item Group:  None Status:  None
Privacy:  Public Assigned to:  None
Open/Closed:  Open Release: 
Fixed Release:  None Fixed Feature Release:  None

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Wed 25 Apr 2012 06:26:46 AM UTC, comment #1:

All parse_config() calls do not check return value, run_exec() does not close
unneeded descriptors and CVS_FOPEN does not set O_CLOEXEC, so there is
possibility external command gets access to CVS configuration file.

I think copying final fclose() after set_defaults_and_return label is the best
solution. Move is not enough because the non-error path would return without
closing the file.

Petr Pisar <petrp>
Mon 23 Apr 2012 08:26:36 PM UTC, original submission:

We are developing a tool to find bugs, and it flagged a potential error in CVS.
We are checking CVS version 1.11.23.
In parse_config() in src/parseinfo.c, the config file is opened at line 274:

274: fp_info = CVS_FOPEN (infopath, "r");

The file is closed if everything goes well:

461: if (fclose (fp_info) < 0)

But if there is a syntax error, the file is not closed:

321: p = strchr (line, '=');
322: if (p == NULL)
323: {
323: /* Probably should be printing line number. */
324: error (0, 0, "syntax error in %s: line '%s' is missing '='",
325: infopath, line);
326: goto error_return;
327: }
474: error_return:
475: if (!logHistory)
476: logHistory = xstrdup (ALL_HISTORY_REC_TYPES);
477: if (infopath != NULL)
478: free (infopath);
479: if (line != NULL)
480: free (line);
// Shall we have something like
// if (fp_info) fclose(fp_info);
// here?
481: return -1;

Since the problem is due to a syntax error, shall we still close the file?
We may just move the call to fclose() into the error_return block.
Else the file would be left opened after the function returns.

Is this a real problem? Any confirmation or clarification is
appreciated. Thanks.



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Attach Files:

Attached Files
file #44074:  cvs-1.11.23-Close-a-configuration-file-on-a-syntax-error.patch added by petrp (977B - application/octet-stream - Proposed fix)


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    Follows 1 latest change.

    Date Changed by Updated Field Previous Value => Replaced by
    2018-05-03 petrp Attached File- => Added cvs-1.11.23-Close-a-configuration-file-on-a-syntax-error.patch, #44074

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