Re: [PATCH bpf] xsk: Check if a queue exists during umem setup
From: Björn Töpel <hidden>
Date: 2019-01-14 18:37:56
Also in:
intel-wired-lan
On 2019-01-14 18:50, Krzysztof Kazimierczak wrote:
From: Krzysztof Kazimierczak <redacted>
In the xdp_umem_assign_dev() path, the xsk code does not
check if a queue for which umem is to be created exists.
It leads to a situation where umem is not assigned to any
Tx/Rx queue of a netdevice, without notifying the stack
about an error. This affects both XDP_SKB and XDP_DRV
modes - in case of XDP_DRV_ZC, queue index is checked by
the driver.
This patch fixes xsk code, so that in both XDP_SKB and
XDP_DRV mode of AF_XDP, an error is returned when requested
queue index exceedes an existing maximum.
Fixes: c9b47cc1fabca ("xsk: fix bug when trying to use both copy and zero-copy on one queue id")
Reported-by: Jakub Spizewski <redacted>
Signed-off-by: Krzysztof Kazimierczak <redacted>Thank you for this! LGTM! Acked-by: Björn Töpel <redacted> Adding intel-wired-lan. Björn
quoted hunk
--- net/xdp/xdp_umem.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index a264cf2accd0..d4de871e7d4d 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c@@ -41,13 +41,20 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) * not know if the device has more tx queues than rx, or the opposite. * This might also change during run time. */ -static void xdp_reg_umem_at_qid(struct net_device *dev, struct xdp_umem *umem, - u16 queue_id) +static int xdp_reg_umem_at_qid(struct net_device *dev, struct xdp_umem *umem, + u16 queue_id) { + if (queue_id >= max_t(unsigned int, + dev->real_num_rx_queues, + dev->real_num_tx_queues)) + return -EINVAL; + if (queue_id < dev->real_num_rx_queues) dev->_rx[queue_id].umem = umem; if (queue_id < dev->real_num_tx_queues) dev->_tx[queue_id].umem = umem; + + return 0; } struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev,@@ -88,7 +95,10 @@ int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev, goto out_rtnl_unlock; } - xdp_reg_umem_at_qid(dev, umem, queue_id); + err = xdp_reg_umem_at_qid(dev, umem, queue_id); + if (err) + goto out_rtnl_unlock; + umem->dev = dev; umem->queue_id = queue_id; if (force_copy)