From 5c0d09241255f3b178056b139bb5f4cdff4a3aa6 Mon Sep 17 00:00:00 2001 From: Joshua Washington Date: Wed, 18 Dec 2024 05:34:12 -0800 Subject: [PATCH] gve: guard XDP xmit NDO on existence of xdp queues BugLink: https://bugs.launchpad.net/bugs/2106632 commit ff7c2dea9dd1a436fc79d6273adffdcc4a7ffea3 upstream. In GVE, dedicated XDP queues only exist when an XDP program is installed and the interface is up. As such, the NDO XDP XMIT callback should return early if either of these conditions are false. In the case of no loaded XDP program, priv->num_xdp_queues=0 which can cause a divide-by-zero error, and in the case of interface down, num_xdp_queues remains untouched to persist XDP queue count for the next interface up, but the TX pointer itself would be NULL. The XDP xmit callback also needs to synchronize with a device transitioning from open to close. This synchronization will happen via the GVE_PRIV_FLAGS_NAPI_ENABLED bit along with a synchronize_net() call, which waits for any RCU critical sections at call-time to complete. Fixes: 39a7f4aa3e4a ("gve: Add XDP REDIRECT support for GQI-QPL format") Cc: stable@vger.kernel.org Signed-off-by: Joshua Washington Signed-off-by: Praveen Kaligineedi Reviewed-by: Praveen Kaligineedi Reviewed-by: Shailend Chand Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman CVE-2024-57932 Signed-off-by: Manuel Diewald Signed-off-by: Mehmet Basaran --- drivers/net/ethernet/google/gve/gve_main.c | 3 +++ drivers/net/ethernet/google/gve/gve_tx.c | 5 ++++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c index 65fa4719545c..d08547d76637 100644 --- a/drivers/net/ethernet/google/gve/gve_main.c +++ b/drivers/net/ethernet/google/gve/gve_main.c @@ -1767,6 +1767,9 @@ static void gve_turndown(struct gve_priv *priv) gve_clear_napi_enabled(priv); gve_clear_report_stats(priv); + + /* Make sure that all traffic is finished processing. */ + synchronize_net(); } static void gve_turnup(struct gve_priv *priv) diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c index 62981dd60103..afbd9b43e57b 100644 --- a/drivers/net/ethernet/google/gve/gve_tx.c +++ b/drivers/net/ethernet/google/gve/gve_tx.c @@ -777,9 +777,12 @@ int gve_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, struct gve_tx_ring *tx; int i, err = 0, qid; - if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK) || !priv->xdp_prog) return -EINVAL; + if (!gve_get_napi_enabled(priv)) + return -ENETDOWN; + qid = gve_xdp_tx_queue_id(priv, smp_processor_id() % priv->num_xdp_queues);