From 5d0001f01521eb923c16cd69c807c655ae9acb54 Mon Sep 17 00:00:00 2001
From: "Frank Ch. Eigler" <fche@redhat.com>
Date: Tue, 22 Sep 2009 16:17:50 +0000
Subject: [PATCH] re PR libmudflap/41433 (security: mudflap accepts environment
variables if setuid)
2009-09-22 Frank Ch. Eigler <fche@redhat.com>
PR libmudflap/41433
* mf-runtime.c (__mf_init): Ignore $MUDFLAP_OPTIONS if
running setuid or setgid.
From-SVN: r152026
---
libmudflap/ChangeLog | 6 ++++++
libmudflap/mf-runtime.c | 13 +++++++++++--
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/libmudflap/ChangeLog b/libmudflap/ChangeLog
index e51c109bbac6..f65cf2ab3d36 100644
--- a/libmudflap/ChangeLog
+++ b/libmudflap/ChangeLog
@@ -1,3 +1,9 @@
+2009-09-22 Frank Ch. Eigler <fche@redhat.com>
+
+ PR libmudflap/41433
+ * mf-runtime.c (__mf_init): Ignore $MUDFLAP_OPTIONS if
+ running setuid or setgid.
+
2009-09-01 Loren J. Rittle <ljrittle@acm.org>
* mf-runtime.c (__mf_init): Support FreeBSD.
diff --git a/libmudflap/mf-runtime.c b/libmudflap/mf-runtime.c
index 3bfaf02b6a08..08a50c218073 100644
--- a/libmudflap/mf-runtime.c
+++ b/libmudflap/mf-runtime.c
@@ -303,6 +303,14 @@ __mf_set_default_options ()
#ifdef LIBMUDFLAPTH
__mf_opts.thread_stack = 0;
#endif
+
+ /* PR41443: Beware that the above flags will be applied to
+ setuid/setgid binaries, and cannot be overriden with
+ $MUDFLAP_OPTIONS. So the defaults must be non-exploitable.
+
+ Should we consider making the default violation_mode something
+ harsher than viol_nop? OTOH, glibc's MALLOC_CHECK_ is disabled
+ by default for these same programs. */
}
static struct mudoption
@@ -442,7 +450,7 @@ __mf_usage ()
"This is a %s%sGCC \"mudflap\" memory-checked binary.\n"
"Mudflap is Copyright (C) 2002-2009 Free Software Foundation, Inc.\n"
"\n"
- "The mudflap code can be controlled by an environment variable:\n"
+ "Unless setuid, a program's mudflap options be set by an environment variable:\n"
"\n"
"$ export MUDFLAP_OPTIONS='<options>'\n"
"$ <mudflapped_program>\n"
@@ -711,7 +719,8 @@ __mf_init ()
__mf_set_default_options ();
- ov = getenv ("MUDFLAP_OPTIONS");
+ if (getuid () == geteuid () && getgid () == getegid ()) /* PR41433, not setuid */
+ ov = getenv ("MUDFLAP_OPTIONS");
if (ov)
{
int rc = __mfu_set_options (ov);
--
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