On 1/22/25 14:49, Dan Carpenter wrote:
The "payload" variable is type size_t, however the nlmsg_total_size()
function will a few bytes to it and then truncate the result to type
int. That means that if "payload" is more than UINT_MAX the alloc_skb()
In the code it's INT_MAX, would be best to have the same used in both
places (or explain it so it's obvious)
function might allocate a buffer which is smaller than intended.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: bfa83a9e03cf ("[NETLINK]: Type-safe netlink messages/attributes interface")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
include/net/netlink.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/net/netlink.h b/include/net/netlink.h
index e015ffbed819..ca7a8152e6d4 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -1015,6 +1015,8 @@ static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
*/
static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
{
+ if (payload > INT_MAX)
+ return NULL;
return alloc_skb(nlmsg_total_size(payload), flags);
}
