From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 7 Oct 2010 19:59:29 +0000 (-0700)
Subject: sysctl: fix min/max handling in __do_proc_doulongvec_minmax()
X-Git-Tag: v2.6.36-rc8~34
X-Git-Url: http://bbs.cooldavid.org/git/?p=net-next-2.6.git;a=commitdiff_plain;h=27b3d80a7b6adcf069b5e869e4efcc3a79f88a91

sysctl: fix min/max handling in __do_proc_doulongvec_minmax()

When proc_doulongvec_minmax() is used with an array of longs, and no
min/max check requested (.extra1 or .extra2 being NULL), we dereference a
NULL pointer for the second element of the array.

Noticed while doing some changes in network stack for the "16TB problem"

Fix is to not change min & max pointers in __do_proc_doulongvec_minmax(),
so that all elements of the vector share an unique min/max limit, like
proc_dointvec_minmax().

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index f88552c6d22..3a45c224770 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2485,7 +2485,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 		kbuf[left] = 0;
 	}
 
-	for (; left && vleft--; i++, min++, max++, first=0) {
+	for (; left && vleft--; i++, first = 0) {
 		unsigned long val;
 
 		if (write) {