From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Wang, Xiaoming" Subject: [PATCH] net: ipv4: current group_info should be put after using. Date: Fri, 11 Apr 2014 22:53:21 -0400 Message-ID: <1397271201.2575.4.camel@wxm-ubuntu> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: chuansheng.liu@intel.com, dongxing.zhang@intel.com, xiaoming.wang@intel.com To: davem@davemloft.net, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This is a typical refcount leak exploitable by unprivileged users. Current group_info had been got in ping_init_sock and group_info->usage increased. But the usage hasn't decreased anywhere in ping. This will make this group_info never freed. Signed-off-by: Chuansheng Liu Signed-off-by: Zhang Dongxing Signed-off-by: xiaoming wang --- net/ipv4/ping.c | 15 +++++++++++---- 1 files changed, 11 insertions(+), 4 deletions(-) diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index f4b19e5..8210964 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -252,26 +252,33 @@ int ping_init_sock(struct sock *sk) { struct net *net = sock_net(sk); kgid_t group = current_egid(); - struct group_info *group_info = get_current_groups(); - int i, j, count = group_info->ngroups; + struct group_info *group_info; + int i, j, count; kgid_t low, high; + int ret = 0; inet_get_ping_group_range_net(net, &low, &high); if (gid_lte(low, group) && gid_lte(group, high)) return 0; + group_info = get_current_groups(); + count = group_info->ngroups; for (i = 0; i < group_info->nblocks; i++) { int cp_count = min_t(int, NGROUPS_PER_BLOCK, count); for (j = 0; j < cp_count; j++) { kgid_t gid = group_info->blocks[i][j]; if (gid_lte(low, gid) && gid_lte(gid, high)) - return 0; + goto out_release_group; } count -= cp_count; } - return -EACCES; + ret = -EACCES; + +out_release_group: + put_group_info(group_info); + return ret; } EXPORT_SYMBOL_GPL(ping_init_sock); -- 1.7.1