From: Vasiliy Kulikov Date: Mon, 14 Feb 2011 15:49:23 +0000 (+0100) Subject: bridge: netfilter: fix information leak X-Git-Tag: v2.6.39-rc1~468^2~10^2~48 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d846f71195d57b0bbb143382647c2c6638b04c5a;p=profile%2Fivi%2Fkernel-x86-ivi.git bridge: netfilter: fix information leak 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 --- diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 5f1825d..893669c 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -1107,6 +1107,8 @@ 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)