Since we cannot make sure that the 'hook_mask' will always be none
zero here. If it equals to zero, the num_hooks will be zero too,
and then kmalloc() will return ZERO_SIZE_PTR, which is (void *)16.
Then the following error check will fails:
ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
if (ops == NULL)
return ERR_PTR(-ENOMEM);
So this patch will fix this with just doing the zero check before
kmalloc() is called.
Maybe the case above will never happen here, but in theory.
Signed-off-by: Xiubo Li <[email protected]>
---
Changes in V2:
- Using the nf.git tree instead.
net/netfilter/x_tables.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 582c9cf..e117fd0 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1221,6 +1221,9 @@ xt_hook_ops_alloc(const struct xt_table *table, nf_hookfn
*fn)
uint8_t hooknum;
struct nf_hook_ops *ops;
+ if (!num_hooks)
+ return ERR_PTR(-EINVAL);
+
ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
if (ops == NULL)
return ERR_PTR(-ENOMEM);
--
1.8.3.1
