[PATCH nf] netfilter: ebtables: zero chainstack array
Florian Westphal <[email protected]>
| Newsgroups | gmane.comp.security.firewalls.netfilter.devel |
|---|---|
| Message-ID | <[email protected]> |
sashiko reports:
looking at ebtables table
translation, could a sparse cpu_possible_mask lead to an uninitialized pointer
free?
If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible,
but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at
CPU 2, the cleanup loop will blindly decrement and call vfree() on
newinfo->chainstack[1].
Not a real-world bug, such allocation isn't expected to fail
in the first place.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <[email protected]>
---
A case could be made that chain/jumpstack should be
GFP_KERNEL_ACCOUNT, but such change is not related to
this one.
net/bridge/netfilter/ebtables.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 5b74ff827493..48187598cdd0 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -921,8 +921,7 @@ static int translate_table(struct net *net, const char *name,
* if an error occurs
*/
newinfo->chainstack =
- vmalloc_array(nr_cpu_ids,
- sizeof(*(newinfo->chainstack)));
+ vcalloc(nr_cpu_ids, sizeof(*(newinfo->chainstack)));
if (!newinfo->chainstack)
return -ENOMEM;
for_each_possible_cpu(i) {
--
2.54.0