Commit cbfe53599eeb for kernel
commit cbfe53599eebffd188938ab6774cc41794f6f9d5
Author: Florian Westphal <fw@strlen.de>
Date: Sat Jul 4 10:23:31 2026 +0200
netfilter: ebtables: zero chainstack array
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.
Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <fw@strlen.de>
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) {