Messages in this thread Patch in this message | | | Date | Tue, 24 Aug 2010 15:45:27 -0700 | From | Greg KH <> | Subject | [082/114] can-raw: Fix skb_orphan_try handling |
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2.6.35-stable review patch. If anyone has any objections, please let us know.
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From: Oliver Hartkopp <socketcan@hartkopp.net>
commit cff0d6e6edac7672b3f915bb4fb59f279243b7f9 upstream.
Commit fc6055a5ba31e2c14e36e8939f9bf2b6d586a7f5 (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: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- include/linux/skbuff.h | 4 +++- net/can/raw.c | 4 ++++ 2 files changed, 7 insertions(+), 1 deletion(-)
--- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -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; }; --- a/net/can/raw.c +++ b/net/can/raw.c @@ -655,6 +655,10 @@ static int raw_sendmsg(struct kiocb *ioc 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;
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