From 5449a5ca9bc27dd51a462de7ca0b1cd861cd2bd0 Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Mon, 21 Dec 2015 10:55:45 -0800 Subject: [PATCH] addrconf: always initialize sysctl table data 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 Acked-by: Hannes Frederic Sowa Tested-by: Sasha Levin Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- 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 17f8e7ea133b..1f21087accab 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5369,13 +5369,10 @@ 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); -- 2.20.1