[patch 2/2 v2] tipc: potential divide by zero in tipc_link_recv_fragment()

Dan Carpenter
2013-05-06T19:31:34Z

The worry here is that fragm_sz could be zero since it comes from
skb->data.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: fix a whitespace issue

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 3a6064b3..de94493 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2524,14 +2524,16 @@ int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
u32 msg_sz = msg_size(imsg);
u32 fragm_sz = msg_data_sz(fragm);
- u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
+ u32 exp_fragm_cnt;
u32 max = TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
+
if (msg_type(imsg) == TIPC_MCAST_MSG)
max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
- if (msg_size(imsg) > max) {
+ if (fragm_sz == 0 || msg_size(imsg) > max) {
kfree_skb(fbuf);
return 0;
}
+ exp_fragm_cnt = msg_sz / fragm_sz + !!(msg_sz % fragm_sz);
pbuf = tipc_buf_acquire(msg_size(imsg));
if (pbuf != NULL) {
pbuf->next = *pending;