From: Vasiliy Kulikov Date: Mon, 14 Feb 2011 15:49:23 +0000 (+0100) Subject: bridge: netfilter: fix information leak X-Git-Tag: v2.6.32.37~39 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a04a632411960cb96d5b9defa571eb8128999f11;p=karo-tx-linux.git bridge: netfilter: fix information leak commit d846f71195d57b0bbb143382647c2c6638b04c5a upstream. Struct tmp is copied from userspace. It is not checked whether the "name" field is NULL terminated. This may lead to buffer overflow and passing contents of kernel stack as a module name to try_then_request_module() and, consequently, to modprobe commandline. It would be seen by all userspace processes. Signed-off-by: Vasiliy Kulikov Signed-off-by: Patrick McHardy Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 0b7f262cd148..d73d47f2a4ad 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -979,6 +979,8 @@ static int do_replace(struct net *net, void __user *user, unsigned int len) if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) return -ENOMEM; + tmp.name[sizeof(tmp.name) - 1] = 0; + countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; newinfo = vmalloc(sizeof(*newinfo) + countersize); if (!newinfo)