* [PATCH] xfrm: init skb_head lock for transport-mode packets
@ 2018-01-04 10:36 Artem Savkov
2018-01-04 11:01 ` Herbert Xu
0 siblings, 1 reply; 5+ messages in thread
From: Artem Savkov @ 2018-01-04 10:36 UTC (permalink / raw)
To: Herbert Xu; +Cc: Steffen Klassert, netdev, linux-kernel, Artem Savkov
Commit acf568ee859f "xfrm: Reinject transport-mode packets through tasklet"
adds an sk_buff_head queue, but never initializes trans->queue.lock, which
results in a "spinlock bad magic" BUG on skb_queue_tail() call in
xfrm_trans_queue.
Use skb_queue_head_init() instead of __skb_queue_head_init() to properly
initialize said lock.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
---
net/xfrm/xfrm_input.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 26b10eb7a206..d5389b9dbbb9 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -542,7 +542,7 @@ void __init xfrm_input_init(void)
struct xfrm_trans_tasklet *trans;
trans = &per_cpu(xfrm_trans_tasklet, i);
- __skb_queue_head_init(&trans->queue);
+ skb_queue_head_init(&trans->queue);
tasklet_init(&trans->tasklet, xfrm_trans_reinject,
(unsigned long)trans);
}
--
2.13.6
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] xfrm: init skb_head lock for transport-mode packets
2018-01-04 10:36 [PATCH] xfrm: init skb_head lock for transport-mode packets Artem Savkov
@ 2018-01-04 11:01 ` Herbert Xu
2018-01-04 11:20 ` Artem Savkov
0 siblings, 1 reply; 5+ messages in thread
From: Herbert Xu @ 2018-01-04 11:01 UTC (permalink / raw)
To: Artem Savkov; +Cc: Steffen Klassert, netdev, linux-kernel
On Thu, Jan 04, 2018 at 11:36:28AM +0100, Artem Savkov wrote:
> Commit acf568ee859f "xfrm: Reinject transport-mode packets through tasklet"
> adds an sk_buff_head queue, but never initializes trans->queue.lock, which
> results in a "spinlock bad magic" BUG on skb_queue_tail() call in
> xfrm_trans_queue.
> Use skb_queue_head_init() instead of __skb_queue_head_init() to properly
> initialize said lock.
>
> Signed-off-by: Artem Savkov <asavkov@redhat.com>
Thanks for catching this. But we don't need the lock as this
is meant to be per-CPU only. So we should remove the locking
instead:
---8<---
xfrm: Use __skb_queue_tail in xfrm_trans_queue
We do not need locking in xfrm_trans_queue because it is designed
to use per-CPU buffers. However, the original code incorrectly
used skb_queue_tail which takes the lock. This patch switches
it to __skb_queue_tail instead.
Reported-by: Artem Savkov <asavkov@redhat.com>
Fixes: acf568ee859f ("xfrm: Reinject transport-mode packets...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 098f47a..1eb0bba 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -511,7 +511,7 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb,
XFRM_TRANS_SKB_CB(skb)->finish = finish;
XFRM_TRANS_SKB_CB(skb)->net = net;
- skb_queue_tail(&trans->queue, skb);
+ __skb_queue_tail(&trans->queue, skb);
tasklet_schedule(&trans->tasklet);
return 0;
}
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] xfrm: init skb_head lock for transport-mode packets
2018-01-04 11:01 ` Herbert Xu
@ 2018-01-04 11:20 ` Artem Savkov
2018-01-04 11:25 ` [PATCH v2] xfrm: Use __skb_queue_tail in xfrm_trans_queue Herbert Xu
0 siblings, 1 reply; 5+ messages in thread
From: Artem Savkov @ 2018-01-04 11:20 UTC (permalink / raw)
To: Herbert Xu; +Cc: Steffen Klassert, netdev, linux-kernel
On Thu, Jan 04, 2018 at 10:01:32PM +1100, Herbert Xu wrote:
> On Thu, Jan 04, 2018 at 11:36:28AM +0100, Artem Savkov wrote:
> > Commit acf568ee859f "xfrm: Reinject transport-mode packets through tasklet"
> > adds an sk_buff_head queue, but never initializes trans->queue.lock, which
> > results in a "spinlock bad magic" BUG on skb_queue_tail() call in
> > xfrm_trans_queue.
> > Use skb_queue_head_init() instead of __skb_queue_head_init() to properly
> > initialize said lock.
> >
> > Signed-off-by: Artem Savkov <asavkov@redhat.com>
>
> Thanks for catching this. But we don't need the lock as this
> is meant to be per-CPU only. So we should remove the locking
> instead:
Right, thats a better solution.
Reported-and-tested-by: Artem Savkov <asavkov@redhat.com>
Thank you.
> ---8<---
> xfrm: Use __skb_queue_tail in xfrm_trans_queue
>
> We do not need locking in xfrm_trans_queue because it is designed
> to use per-CPU buffers. However, the original code incorrectly
> used skb_queue_tail which takes the lock. This patch switches
> it to __skb_queue_tail instead.
>
> Reported-by: Artem Savkov <asavkov@redhat.com>
> Fixes: acf568ee859f ("xfrm: Reinject transport-mode packets...")
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
>
> diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
> index 098f47a..1eb0bba 100644
> --- a/net/xfrm/xfrm_input.c
> +++ b/net/xfrm/xfrm_input.c
> @@ -511,7 +511,7 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb,
>
> XFRM_TRANS_SKB_CB(skb)->finish = finish;
> XFRM_TRANS_SKB_CB(skb)->net = net;
> - skb_queue_tail(&trans->queue, skb);
> + __skb_queue_tail(&trans->queue, skb);
> tasklet_schedule(&trans->tasklet);
> return 0;
> }
--
Regards,
Artem
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2] xfrm: Use __skb_queue_tail in xfrm_trans_queue
2018-01-04 11:20 ` Artem Savkov
@ 2018-01-04 11:25 ` Herbert Xu
2018-01-05 10:31 ` Steffen Klassert
0 siblings, 1 reply; 5+ messages in thread
From: Herbert Xu @ 2018-01-04 11:25 UTC (permalink / raw)
To: Artem Savkov; +Cc: Steffen Klassert, netdev, linux-kernel
On Thu, Jan 04, 2018 at 12:20:26PM +0100, Artem Savkov wrote:
> Right, thats a better solution.
>
> Reported-and-tested-by: Artem Savkov <asavkov@redhat.com>
Thanks!
But I just realised that this patch is based on my dirty tree.
So here is a rebased version:
---8<---
We do not need locking in xfrm_trans_queue because it is designed
to use per-CPU buffers. However, the original code incorrectly
used skb_queue_tail which takes the lock. This patch switches
it to __skb_queue_tail instead.
Reported-and-tested-by: Artem Savkov <asavkov@redhat.com>
Fixes: acf568ee859f ("xfrm: Reinject transport-mode packets...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 444fa37..9dbf425 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -508,7 +508,7 @@ int xfrm_trans_queue(struct sk_buff *skb,
return -ENOBUFS;
XFRM_TRANS_SKB_CB(skb)->finish = finish;
- skb_queue_tail(&trans->queue, skb);
+ __skb_queue_tail(&trans->queue, skb);
tasklet_schedule(&trans->tasklet);
return 0;
}
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2] xfrm: Use __skb_queue_tail in xfrm_trans_queue
2018-01-04 11:25 ` [PATCH v2] xfrm: Use __skb_queue_tail in xfrm_trans_queue Herbert Xu
@ 2018-01-05 10:31 ` Steffen Klassert
0 siblings, 0 replies; 5+ messages in thread
From: Steffen Klassert @ 2018-01-05 10:31 UTC (permalink / raw)
To: Herbert Xu; +Cc: Artem Savkov, netdev, linux-kernel
On Thu, Jan 04, 2018 at 10:25:07PM +1100, Herbert Xu wrote:
> On Thu, Jan 04, 2018 at 12:20:26PM +0100, Artem Savkov wrote:
>
> > Right, thats a better solution.
> >
> > Reported-and-tested-by: Artem Savkov <asavkov@redhat.com>
>
> Thanks!
>
> But I just realised that this patch is based on my dirty tree.
> So here is a rebased version:
>
> ---8<---
> We do not need locking in xfrm_trans_queue because it is designed
> to use per-CPU buffers. However, the original code incorrectly
> used skb_queue_tail which takes the lock. This patch switches
> it to __skb_queue_tail instead.
>
> Reported-and-tested-by: Artem Savkov <asavkov@redhat.com>
> Fixes: acf568ee859f ("xfrm: Reinject transport-mode packets...")
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Applied, thanks everyone!
^ permalink raw reply [flat|nested] 5+ messages in thread
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2018-01-04 10:36 [PATCH] xfrm: init skb_head lock for transport-mode packets Artem Savkov
2018-01-04 11:01 ` Herbert Xu
2018-01-04 11:20 ` Artem Savkov
2018-01-04 11:25 ` [PATCH v2] xfrm: Use __skb_queue_tail in xfrm_trans_queue Herbert Xu
2018-01-05 10:31 ` Steffen Klassert
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