[maverick, maverick/ti-omap4 CVE 4/5] auxv: require the target to be tracable (or yourself)

[Andy Whitcroft]

From: Al Viro <viro at zeniv.linux.org.uk>

same as for environ, except that we didn't do any checks to
prevent access after suid execve

Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>

(cherry picked from commit 2fadaef41283aad7100fa73f01998cddaca25833)
CVE-2011-1020
BugLink: http://bugs.launchpad.net/bugs/813026
Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 fs/proc/base.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 1953009..331c4f6 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -280,9 +280,9 @@ out:
 
 static int proc_pid_auxv(struct task_struct *task, char *buffer)
 {
-	int res = 0;
-	struct mm_struct *mm = get_task_mm(task);
-	if (mm) {
+	struct mm_struct *mm = mm_for_maps(task);
+	int res = PTR_ERR(mm);
+	if (mm && !IS_ERR(mm)) {
 		unsigned int nwords = 0;
 		do {
 			nwords += 2;
-- 
1.7.4.1