From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 16 Feb 2011 03:52:11 +0000 (-0500)
Subject: auxv: require the target to be tracable (or yourself)
X-Git-Tag: firefly_0821_release~7613^2~1827^2~13
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2fadaef41283aad7100fa73f01998cddaca25833;p=firefly-linux-kernel-4.4.55.git

auxv: require the target to be tracable (or yourself)

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

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

diff --git a/fs/proc/base.c b/fs/proc/base.c
index fc471b8766d1..e94b58b496f1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -281,9 +281,9 @@ 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;