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 <segoon@xxxxxxxxxxxx> --- Compile tested. net/bridge/netfilter/ebtables.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 5f1825d..1ea820b 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) -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
