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Commit cff0d6e6 authored by Oliver Hartkopp's avatar Oliver Hartkopp Committed by David S. Miller
Browse files

can-raw: Fix skb_orphan_try handling 

Commit fc6055a5 (net: Introduce
skb_orphan_try()) allows an early orphan of the skb and takes care on
tx timestamping, which needs the sk-reference in the skb on driver level.
So does the can-raw socket, which has not been taken into account here.

The patch below adds a 'prevent_sk_orphan' bit in the skb tx shared info,
which fixes the problem discovered by Matthias Fuchs here:

      http://marc.info/?t=128030411900003&r=1&w=2



Even if it's not a primary tx timestamp topic it fits well into some skb
shared tx context. Or should be find a different place for the information to
protect the sk reference until it reaches the driver level?

Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3578b0c8

include/linux/skbuff.h

+3 −1
Original line number Diff line number Diff line
@@ -169,6 +169,7 @@ struct skb_shared_hwtstamps { 
 * @software:		generate software time stamp

 * @in_progress:	device driver is going to provide

 *			hardware time stamp

 * @prevent_sk_orphan:	make sk reference available on driver level

 * @flags:		all shared_tx flags

 *

 * These flags are attached to packets as part of the
@@ -178,7 +179,8 @@ union skb_shared_tx { 
	struct {

		__u8	hardware:1,

			software:1,

			in_progress:1;

			in_progress:1,

			prevent_sk_orphan:1;

	};

	__u8 flags;

};

net/can/raw.c

+4 −0
Original line number Diff line number Diff line
@@ -650,6 +650,10 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock, 
	err = sock_tx_timestamp(msg, sk, skb_tx(skb));

	if (err < 0)

		goto free_skb;



	/* to be able to check the received tx sock reference in raw_rcv() */

	skb_tx(skb)->prevent_sk_orphan = 1;



	skb->dev = dev;

	skb->sk  = sk;