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authorHoang Le <hoang.h.le@dektek.com.au>2018-02-08 17:16:25 +0100
committerDavid S. Miller <davem@davemloft.net>2018-02-08 15:30:40 -0500
commit55b3280d1e471795c08dbbe17325720a843e104c (patch)
tree540f61caa564a39a197d6980c0a244f1cd93a807
parenteb53f7af6f15285e2f6ada97285395343ce9f433 (diff)
tipc: fix skb truesize/datasize ratio control
In commit d618d09a68e4 ("tipc: enforce valid ratio between skb truesize and contents") we introduced a test for ensuring that the condition truesize/datasize <= 4 is true for a received buffer. Unfortunately this test has two problems. - Because of the integer arithmetics the test if (skb->truesize / buf_roundup_len(skb) > 4) will miss all ratios [4 < ratio < 5], which was not the intention. - The buffer returned by skb_copy() inherits skb->truesize of the original buffer, which doesn't help the situation at all. In this commit, we change the ratio condition and replace skb_copy() with a call to skb_copy_expand() to finally get this right. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/tipc/msg.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 55d8ba92291d..4e1c6f6450bb 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -208,8 +208,8 @@ bool tipc_msg_validate(struct sk_buff **_skb)
int msz, hsz;
/* Ensure that flow control ratio condition is satisfied */
- if (unlikely(skb->truesize / buf_roundup_len(skb) > 4)) {
- skb = skb_copy(skb, GFP_ATOMIC);
+ if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) {
+ skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC);
if (!skb)
return false;
kfree_skb(*_skb);

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