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 <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Vasiliy Kulikov 2011-02-14 16:49:23 +01:00 committed by Patrick McHardy
parent 44bd4de9c2
commit d846f71195
1 changed files with 2 additions and 0 deletions

View File

@ -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)