[NET]: Add skb->truesize assertion checking.
Add some sanity checking. truesize should be at least sizeof(struct
sk_buff) plus the current packet length. If not, then truesize is
seriously mangled and deserves a kernel log message.
Currently we'll do the check for release of stream socket buffers.
But we can add checks to more spots over time.
Incorporating ideas from Herbert Xu.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c4619a4..f8f2347 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -344,6 +344,13 @@
void *here);
extern void skb_under_panic(struct sk_buff *skb, int len,
void *here);
+extern void skb_truesize_bug(struct sk_buff *skb);
+
+static inline void skb_truesize_check(struct sk_buff *skb)
+{
+ if (unlikely((int)skb->truesize < sizeof(struct sk_buff) + skb->len))
+ skb_truesize_bug(skb);
+}
extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
int getfrag(void *from, char *to, int offset,
diff --git a/include/net/sock.h b/include/net/sock.h
index af2b054..ff8b0da 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -454,6 +454,7 @@
static inline void sk_stream_free_skb(struct sock *sk, struct sk_buff *skb)
{
+ skb_truesize_check(skb);
sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
sk->sk_wmem_queued -= skb->truesize;
sk->sk_forward_alloc += skb->truesize;