From: Ilya Maximets i.maximets@samsung.com
[ Upstream commit 675716400da6f15b9d3db04ef74ee74ca9a00af3 ]
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 Acked-by: Björn Töpel bjorn.topel@intel.com Tested-by: William Tu u9012063@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 547fc4554b22..c90854bc3048 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -218,6 +218,9 @@ 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; @@ -228,12 +231,6 @@ 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)) { @@ -245,7 +242,7 @@ 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; }