From ce0f98ea90a8171cdaf249c0c623b455931d69ec Mon Sep 17 00:00:00 2001 From: Vasiliy Kulikov Date: Mon, 14 Feb 2011 16:49:23 +0100 Subject: [PATCH] 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 Signed-off-by: Andi Kleen --- net/bridge/netfilter/ebtables.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 59ca00e40dec..62675dc51179 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -1098,6 +1098,8 @@ static int do_replace(struct net *net, const void __user *user, 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) -- 2.39.5