[asterisk-dev] bug in app_voicemail.c

[Jim Capp]

Folks,

    There is a bug in app_voicemail.c that causes weird things to happen 
with file permissions.  I have submitted complete information, as well 
as a patch, in bugs.digium.com, ID 0014912.  This affects all versions 
of Asterisk and has a very simple fix.

See attached.

Cheers,

Jim


The voicemail application has a bug where, depending on how it is 
compiled, it doesn't retain the umask value that is read upon module 
load. This is the real source of the problem related to issues 0009231 
and 0007504.

The problem is that since my_umask is not declared static, compilers are 
not required to persist its value. As such, some highly optimized 
compilers will assign it a cpu register rather than variable space on 
the stack. Since my_umask is only set during module load, subsequent 
uses of my_umask are unreliable as the register will surely have been 
overwritten prior to its next use.

What made this difficult to diagnose was that the values seemed 
reasonably close to real umask values, as the functions prior to its use 
were related to the loading of the mask constant VOICEMAIL_FILE_MODE 0666.

The solution is simply to make my_umask static in app_voicemail.c

 From what I can tell, this applies to ALL versions of app_voicemail.c 
including the latest 1.4 and 1.6 branches.

Here is an appropriate patch:

--- app_voicemail-orig.c 2009-04-16 10:27:43.000000000 -0400
+++ app_voicemail.c 2009-04-16 10:28:19.000000000 -0400
@@ -661,7 +661,7 @@
 static char ext_pass_cmd[128];
 static char ext_pass_check_cmd[128];
 
-int my_umask;
+static int my_umask;
 
 #define PWDCHANGE_INTERNAL (1 << 1)
 #define PWDCHANGE_EXTERNAL (1 << 2)


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.digium.com/pipermail/asterisk-dev/attachments/20090416/b632cfe9/attachment.htm