4.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: WANG Cong <xiyou.wangcong@xxxxxxxxx> [ 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@xxxxxxxxxx> Acked-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx> Tested-by: Sasha Levin <sasha.levin@xxxxxxxxxx> Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv6/addrconf.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5267,13 +5267,10 @@ static int addrconf_sysctl_stable_secret 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); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html