misc/68905: core dump ownership issue

[blake frantz]

>Number:         68905
>Category:       misc
>Synopsis:       core dump ownership issue
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Jul 11 02:30:12 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     blake frantz
>Release:        4.9-RC FreeBSD 4.9-RC
>Organization:
none
>Environment:
FreeBSD sbin.nologin.org 4.9-RC FreeBSD 4.9-RC #0: Thu Oct 16 21:45:02 PDT 2003     root at sbin.nologin.org:/usr/src/sys/compile/NOLOGIN  i386

>Description:
if a core file owned by a non root user exists and root runs a process that drops core in the same location, the original core file owned by the non root user is replaced with root's core dump, except the original owner maintains ownership of the core.  linux 2.4, 2.6, and obsd operate in the same manner.  i have not tested other platforms

i do understand that mitigating factors, such as configuring where and how core's are created, but this doens't seem right.


>How-To-Repeat:
trew:~/tmp/q$ ./t
Segmentation fault (core dumped)
trew:~/tmp/q$ md5sum core
90b29a1012aa00c34a18947d98f1b1fb  core
trew:~/tmp/q$ ls -l core
-rw-------    1 trew     users       61440 Jul 10 19:13 core
trew:~/tmp/q$ su
Password:
root:/home/trew/tmp/q# ./t
Segmentation fault (core dumped)
root:/home/trew/tmp/q# md5sum core
371c0748df009ed1da6f189cceff8aca  core
root:/home/trew/tmp/q# ls -l core
-rw-------    1 trew     users       61440 Jul 10 19:13 core

>Fix:
      
>Release-Note:
>Audit-Trail:
>Unformatted: