From 6866b52c56db189f8471a13f951221c45c0089c7 Mon Sep 17 00:00:00 2001
From: WANG Cong <xiyou.wangcong@gmail.com>
Date: Mon, 21 Dec 2015 10:55:45 -0800
Subject: [PATCH] addrconf: always initialize sysctl table data
[ Upstream commit 5449a5ca9bc27dd51a462de7ca0b1cd861cd2bd0 ]
When sysctl performs restrict writes, it allows to write from
a middle position of a sysctl file, which requires us to initialize
the table data before calling proc_dostring() for the write case.
Fixes: 3d1bec99320d ("ipv6: introduce secret_stable to ipv6_devconf")
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv6/addrconf.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a2d685030a34..f4795b0d6e6e 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5267,13 +5267,10 @@ static int addrconf_sysctl_stable_secret(struct ctl_table *ctl, int write,
goto out;
}
- if (!write) {
- err = snprintf(str, sizeof(str), "%pI6",
- &secret->secret);
- if (err >= sizeof(str)) {
- err = -EIO;
- goto out;
- }
+ err = snprintf(str, sizeof(str), "%pI6", &secret->secret);
+ if (err >= sizeof(str)) {
+ err = -EIO;
+ goto out;
}
err = proc_dostring(&lctl, write, buffer, lenp, ppos);
--
2.30.9