[PATCH v3 6/7] pppoatm: don't send frames on not-ready vcc

[Krzysztof Mazur <krzysiek@podlesie.net>]

Patches "atm: detach protocol before closing vcc"
and "pppoatm: allow assign only on a connected socket" fixed
common cases where the pppoatm_send() crashes while sending
frame to not-ready vcc. However there are still some other cases
where we can send frames to vcc, which is flagged as ATM_VF_CLOSE
(for instance after vcc_release_async()) or it's opened but not
ready yet.

Now pppoatm_send(), like vcc_sendmsg(), checks for vcc flags that
indicate that vcc is not ready.

Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: David Woodhouse <David.Woodhouse@intel.com>
---
 net/atm/pppoatm.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
index c4a57bc..bf5d6c9 100644
--- a/net/atm/pppoatm.c
+++ b/net/atm/pppoatm.c
@@ -284,6 +284,10 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
 	bh_lock_sock(sk_atm(vcc));
 	if (sock_owned_by_user(sk_atm(vcc)))
 		goto nospace;
+	if (test_bit(ATM_VF_RELEASED, &vcc->flags)
+			|| test_bit(ATM_VF_CLOSE, &vcc->flags)
+			|| !test_bit(ATM_VF_READY, &vcc->flags))
+		goto nospace;
 
 	switch (pvcc->encaps) {		/* LLC encapsulation needed */
 	case e_llc:
-- 
1.8.0.233.g54991f2