mod_userdir/7271: dereferencing NULL pointer in mod_userdir.c

[Taketo Kabe <ka...@sra-tohoku.co.jp>]

>Number:         7271
>Category:       mod_userdir
>Synopsis:       dereferencing NULL pointer in mod_userdir.c
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    apache
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Sun Feb 18 19:50:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     kabe@sra-tohoku.co.jp
>Release:        httpd-2_0_11-alpha
>Organization:
apache
>Environment:
SunOS 5.8 Generic_108528-05 sun4u sparc SUNW,Ultra-60
gcc version 2.95.2 19991024 (release)
>Description:
modules/mappers/mod_userdir.c:get_suexec_id_doer()
references members of struct passwd pw without calling getpwnam(),
so causes a coredump when CGI is invoked.

>How-To-Repeat:
configure --enable-cgi --disable-cgid (yes, no cgid)
and make the server invoke CGI several times.
The child httpd will coredump on first couple of tries.
>Fix:
Just adding getpwnam() is easy but I'm not convinced enough to
make this MT-safe.

diff -u httpd-2_0_11-alpha/modules/mappers/mod_userdir.c.dist httpd-2_0_11-alpha/modules/mappers/mod_userdir.c
--- httpd-2_0_11-alpha/modules/mappers/mod_userdir.c.dist	Sat Feb 10 23:04:20 2001
+++ httpd-2_0_11-alpha/modules/mappers/mod_userdir.c	Mon Feb 19 12:21:42 2001
@@ -375,6 +375,9 @@
     if (username == NULL) {
         return NULL;
     }
+    if ((pw = getpwnam(username)) == NULL) {	/*XXX MT unsafe*/
+	return NULL;
+    }
 
     if ((ugid = apr_palloc(r->pool, sizeof(ap_unix_identity_t *))) == NULL) {
         return NULL;
>Release-Note:
>Audit-Trail:
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