* [PATCH bpf] xdp: fix possible cq entry leak
[not found] <CGME20190704142509eucas1p268eb9ca87bcc0bffb60891f88f3f6642@eucas1p2.samsung.com>
@ 2019-07-04 14:25 ` Ilya Maximets
2019-07-05 6:42 ` Björn Töpel
2019-07-12 13:07 ` Daniel Borkmann
0 siblings, 2 replies; 4+ messages in thread
From: Ilya Maximets @ 2019-07-04 14:25 UTC (permalink / raw)
To: netdev
Cc: linux-kernel, bpf, xdp-newbies, David S. Miller,
Björn Töpel, Magnus Karlsson, Jonathan Lemon,
Jakub Kicinski, Alexei Starovoitov, Daniel Borkmann,
Ilya Maximets
Completion queue address reservation could not be undone.
In case of bad 'queue_id' or skb allocation failure, reserved entry
will be leaked reducing the total capacity of completion queue.
Fix that by moving reservation to the point where failure is not
possible. Additionally, 'queue_id' checking moved out from the loop
since there is no point to check it there.
Fixes: 35fcde7f8deb ("xsk: support for Tx")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
---
net/xdp/xsk.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index f53a6ef7c155..703cf5ea448b 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -226,6 +226,9 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
mutex_lock(&xs->mutex);
+ if (xs->queue_id >= xs->dev->real_num_tx_queues)
+ goto out;
+
while (xskq_peek_desc(xs->tx, &desc)) {
char *buffer;
u64 addr;
@@ -236,12 +239,6 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
goto out;
}
- if (xskq_reserve_addr(xs->umem->cq))
- goto out;
-
- if (xs->queue_id >= xs->dev->real_num_tx_queues)
- goto out;
-
len = desc.len;
skb = sock_alloc_send_skb(sk, len, 1, &err);
if (unlikely(!skb)) {
@@ -253,7 +250,7 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
addr = desc.addr;
buffer = xdp_umem_get_data(xs->umem, addr);
err = skb_store_bits(skb, 0, buffer, len);
- if (unlikely(err)) {
+ if (unlikely(err) || xskq_reserve_addr(xs->umem->cq)) {
kfree_skb(skb);
goto out;
}
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH bpf] xdp: fix possible cq entry leak
2019-07-04 14:25 ` [PATCH bpf] xdp: fix possible cq entry leak Ilya Maximets
@ 2019-07-05 6:42 ` Björn Töpel
2019-07-08 21:25 ` William Tu
2019-07-12 13:07 ` Daniel Borkmann
1 sibling, 1 reply; 4+ messages in thread
From: Björn Töpel @ 2019-07-05 6:42 UTC (permalink / raw)
To: Ilya Maximets
Cc: Netdev, LKML, bpf, Xdp, David S. Miller, Björn Töpel,
Magnus Karlsson, Jonathan Lemon, Jakub Kicinski,
Alexei Starovoitov, Daniel Borkmann
On Thu, 4 Jul 2019 at 16:25, Ilya Maximets <i.maximets@samsung.com> wrote:
>
> Completion queue address reservation could not be undone.
> In case of bad 'queue_id' or skb allocation failure, reserved entry
> will be leaked reducing the total capacity of completion queue.
>
> Fix that by moving reservation to the point where failure is not
> possible. Additionally, 'queue_id' checking moved out from the loop
> since there is no point to check it there.
>
Good catch, Ilya! Thanks for the patch!
Acked-by: Björn Töpel <bjorn.topel@intel.com>
> Fixes: 35fcde7f8deb ("xsk: support for Tx")
> Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
> ---
> net/xdp/xsk.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> index f53a6ef7c155..703cf5ea448b 100644
> --- a/net/xdp/xsk.c
> +++ b/net/xdp/xsk.c
> @@ -226,6 +226,9 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
>
> mutex_lock(&xs->mutex);
>
> + if (xs->queue_id >= xs->dev->real_num_tx_queues)
> + goto out;
> +
> while (xskq_peek_desc(xs->tx, &desc)) {
> char *buffer;
> u64 addr;
> @@ -236,12 +239,6 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
> goto out;
> }
>
> - if (xskq_reserve_addr(xs->umem->cq))
> - goto out;
> -
> - if (xs->queue_id >= xs->dev->real_num_tx_queues)
> - goto out;
> -
> len = desc.len;
> skb = sock_alloc_send_skb(sk, len, 1, &err);
> if (unlikely(!skb)) {
> @@ -253,7 +250,7 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
> addr = desc.addr;
> buffer = xdp_umem_get_data(xs->umem, addr);
> err = skb_store_bits(skb, 0, buffer, len);
> - if (unlikely(err)) {
> + if (unlikely(err) || xskq_reserve_addr(xs->umem->cq)) {
> kfree_skb(skb);
> goto out;
> }
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH bpf] xdp: fix possible cq entry leak
2019-07-05 6:42 ` Björn Töpel
@ 2019-07-08 21:25 ` William Tu
0 siblings, 0 replies; 4+ messages in thread
From: William Tu @ 2019-07-08 21:25 UTC (permalink / raw)
To: Björn Töpel
Cc: Ilya Maximets, Netdev, LKML, bpf, Xdp, David S. Miller,
Björn Töpel, Magnus Karlsson, Jonathan Lemon,
Jakub Kicinski, Alexei Starovoitov, Daniel Borkmann
On Thu, Jul 4, 2019 at 11:49 PM Björn Töpel <bjorn.topel@gmail.com> wrote:
>
> On Thu, 4 Jul 2019 at 16:25, Ilya Maximets <i.maximets@samsung.com> wrote:
> >
> > Completion queue address reservation could not be undone.
> > In case of bad 'queue_id' or skb allocation failure, reserved entry
> > will be leaked reducing the total capacity of completion queue.
> >
> > Fix that by moving reservation to the point where failure is not
> > possible. Additionally, 'queue_id' checking moved out from the loop
> > since there is no point to check it there.
> >
>
> Good catch, Ilya! Thanks for the patch!
>
> Acked-by: Björn Töpel <bjorn.topel@intel.com>
>
Thanks
Tested-by: William Tu <u9012063@gmail.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH bpf] xdp: fix possible cq entry leak
2019-07-04 14:25 ` [PATCH bpf] xdp: fix possible cq entry leak Ilya Maximets
2019-07-05 6:42 ` Björn Töpel
@ 2019-07-12 13:07 ` Daniel Borkmann
1 sibling, 0 replies; 4+ messages in thread
From: Daniel Borkmann @ 2019-07-12 13:07 UTC (permalink / raw)
To: Ilya Maximets, netdev
Cc: linux-kernel, bpf, xdp-newbies, David S. Miller,
Björn Töpel, Magnus Karlsson, Jonathan Lemon,
Jakub Kicinski, Alexei Starovoitov
On 07/04/2019 04:25 PM, Ilya Maximets wrote:
> Completion queue address reservation could not be undone.
> In case of bad 'queue_id' or skb allocation failure, reserved entry
> will be leaked reducing the total capacity of completion queue.
>
> Fix that by moving reservation to the point where failure is not
> possible. Additionally, 'queue_id' checking moved out from the loop
> since there is no point to check it there.
>
> Fixes: 35fcde7f8deb ("xsk: support for Tx")
> Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Applied, thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-07-04 14:25 ` [PATCH bpf] xdp: fix possible cq entry leak Ilya Maximets
2019-07-05 6:42 ` Björn Töpel
2019-07-08 21:25 ` William Tu
2019-07-12 13:07 ` Daniel Borkmann
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