Commit 55b3280d1e471795c08dbbe17325720a843e104c
Committed by
David S. Miller
1 parent
eb53f7af6f
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>
Showing 1 changed file with 2 additions and 2 deletions Side-by-side Diff
net/tipc/msg.c
... | ... | @@ -208,8 +208,8 @@ |
208 | 208 | int msz, hsz; |
209 | 209 | |
210 | 210 | /* Ensure that flow control ratio condition is satisfied */ |
211 | - if (unlikely(skb->truesize / buf_roundup_len(skb) > 4)) { | |
212 | - skb = skb_copy(skb, GFP_ATOMIC); | |
211 | + if (unlikely(skb->truesize / buf_roundup_len(skb) >= 4)) { | |
212 | + skb = skb_copy_expand(skb, BUF_HEADROOM, 0, GFP_ATOMIC); | |
213 | 213 | if (!skb) |
214 | 214 | return false; |
215 | 215 | kfree_skb(*_skb); |