[1071] in linux-security and linux-alert archive
[linux-security] Re: RESOLV_HOST_CONF
daemon@ATHENA.MIT.EDU (Joshua Cowan)
Sun Aug 25 20:30:15 1996
Date: Sun, 25 Aug 1996 14:32:03 -0500
From: Joshua Cowan <jcowan@jcowan.reslife.okstate.edu>
To: linux-security@tarsier.cv.nrao.edu
In-Reply-To: <Pine.LNX.3.94.960825004049.4817C-100000@newport.thirdwave.net>
>>>>> "REW" == Roger Wolff <R.E.Wolff@et.tudelft.nl> writes:
REW> I'd suggest either dropping priviliges before opening the file
REW> or simply refusing to use the environment variables when euid
REW> != uid (like the LD_LIBRARY_xx family).
I've done this. The patch to ld.so 1.8.2 is included below; of course,
it won't help if your `ping', `traceroute', `rsh', etc., are statically
linked....
--
Joshua Cowan <jcowan@hermit.reslife.okstate.edu> _____________________
http://hermit.reslife.okstate.edu/~jcowan/ | Comp Sci Student
"Very funny, Scotty. Now beam down my clothes." | OSU - Stillwater, OK
PGP key available from any PGP keyserver or by fingering above address.
diff -ru ld.so-1.8.2.orig/d-link/boot1.c ld.so-1.8.2/d-link/boot1.c
--- ld.so-1.8.2.orig/d-link/boot1.c Mon Jun 17 21:11:16 1996
+++ ld.so-1.8.2/d-link/boot1.c Sat Aug 24 07:28:47 1996
@@ -521,6 +521,9 @@
}
else
{
+ /* A temporary hack to patch the resolver library bug. --JC */
+ _dl_unsetenv ("RESOLV_HOST_CONF", envp);
+
_dl_unsetenv("LD_PRELOAD", envp);
_dl_unsetenv("LD_AOUT_PRELOAD", envp);
_dl_preload = NULL;
diff -ru ld.so-1.8.2.orig/ld-so/ld.so.c ld.so-1.8.2/ld-so/ld.so.c
--- ld.so-1.8.2.orig/ld-so/ld.so.c Tue May 28 20:05:13 1996
+++ ld.so-1.8.2/ld-so/ld.so.c Sat Aug 24 07:29:45 1996
@@ -241,6 +241,8 @@
}
else
{
+ unsetenv ("RESOLV_HOST_CONF");
+
/* sorry, Charlie, I can't let you do that */
unsetenv("LD_PRELOAD");
unsetenv("LD_AOUT_PRELOAD");
