net: Fix use after free by removing length arg from sk_data_ready callbacks.
Several spots in the kernel perform a sequence like:
skb_queue_tail(&sk->s_receive_queue, skb);
sk->sk_data_ready(sk, skb->len);
But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up. So this skb->len access is potentially
to freed up memory.
Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.
And finally, no actual implementation of this callback actually uses
the length argument. And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.
So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.
Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/atm/clip.c b/net/atm/clip.c
index 8215f7c..ba291ce 100644
--- a/net/atm/clip.c
+++ b/net/atm/clip.c
@@ -68,7 +68,7 @@
sk = sk_atm(atmarpd);
skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ sk->sk_data_ready(sk);
return 0;
}
diff --git a/net/atm/lec.c b/net/atm/lec.c
index 5a2f602..4c5b8ba 100644
--- a/net/atm/lec.c
+++ b/net/atm/lec.c
@@ -152,7 +152,7 @@
atm_force_charge(priv->lecd, skb2->truesize);
sk = sk_atm(priv->lecd);
skb_queue_tail(&sk->sk_receive_queue, skb2);
- sk->sk_data_ready(sk, skb2->len);
+ sk->sk_data_ready(sk);
}
}
#endif /* defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE) */
@@ -447,7 +447,7 @@
atm_force_charge(priv->lecd, skb2->truesize);
sk = sk_atm(priv->lecd);
skb_queue_tail(&sk->sk_receive_queue, skb2);
- sk->sk_data_ready(sk, skb2->len);
+ sk->sk_data_ready(sk);
}
}
#endif /* defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE) */
@@ -530,13 +530,13 @@
atm_force_charge(priv->lecd, skb->truesize);
sk = sk_atm(priv->lecd);
skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ sk->sk_data_ready(sk);
if (data != NULL) {
pr_debug("about to send %d bytes of data\n", data->len);
atm_force_charge(priv->lecd, data->truesize);
skb_queue_tail(&sk->sk_receive_queue, data);
- sk->sk_data_ready(sk, skb->len);
+ sk->sk_data_ready(sk);
}
return 0;
@@ -616,7 +616,7 @@
pr_debug("%s: To daemon\n", dev->name);
skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ sk->sk_data_ready(sk);
} else { /* Data frame, queue to protocol handlers */
struct lec_arp_table *entry;
unsigned char *src, *dst;
diff --git a/net/atm/mpc.c b/net/atm/mpc.c
index 91dc58f..e8e0e7a 100644
--- a/net/atm/mpc.c
+++ b/net/atm/mpc.c
@@ -706,7 +706,7 @@
dprintk("(%s) control packet arrived\n", dev->name);
/* Pass control packets to daemon */
skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ sk->sk_data_ready(sk);
return;
}
@@ -992,7 +992,7 @@
sk = sk_atm(mpc->mpoad_vcc);
skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ sk->sk_data_ready(sk);
return 0;
}
@@ -1273,7 +1273,7 @@
sk = sk_atm(vcc);
skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ sk->sk_data_ready(sk);
dprintk("exiting\n");
}
diff --git a/net/atm/raw.c b/net/atm/raw.c
index b4f7b9f..2e17e97 100644
--- a/net/atm/raw.c
+++ b/net/atm/raw.c
@@ -25,7 +25,7 @@
struct sock *sk = sk_atm(vcc);
skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, skb->len);
+ sk->sk_data_ready(sk);
}
}
diff --git a/net/atm/signaling.c b/net/atm/signaling.c
index 4176887..523bce7 100644
--- a/net/atm/signaling.c
+++ b/net/atm/signaling.c
@@ -51,7 +51,7 @@
#endif
atm_force_charge(sigd, skb->truesize);
skb_queue_tail(&sk_atm(sigd)->sk_receive_queue, skb);
- sk_atm(sigd)->sk_data_ready(sk_atm(sigd), skb->len);
+ sk_atm(sigd)->sk_data_ready(sk_atm(sigd));
}
static void modify_qos(struct atm_vcc *vcc, struct atmsvc_msg *msg)