octeontx2-pf: fix "UBSAN: shift-out-of-bounds error"

This patch ensures that the RX ring size (rx_pending) is not
set below the permitted length. This avoids UBSAN
shift-out-of-bounds errors when users passes small or zero
ring sizes via ethtool -G.

Fixes: d45d8979840d ("octeontx2-pf: Add basic ethtool support")
Signed-off-by: Anshumali Gaur <agaur@marvell.com>
Link: https://patch.msgid.link/20251219062226.524844-1-agaur@marvell.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
index b90e23dc49de98cbc746818ce467d8e3d21cb04e..b6449f0a9e7dd543ef15b95ffd74b2487bb98f7e 100644 (file)
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ethtool.c
@@ -418,6 +418,14 @@ static int otx2_set_ringparam(struct net_device *netdev,
         */
        if (rx_count < pfvf->hw.rq_skid)
                rx_count =  pfvf->hw.rq_skid;
+
+       if (ring->rx_pending < 16) {
+               netdev_err(netdev,
+                          "rx ring size %u invalid, min is 16\n",
+                          ring->rx_pending);
+               return -EINVAL;
+       }
+
        rx_count = Q_COUNT(Q_SIZE(rx_count, 3));
 
        /* Due pipelining impact minimum 2000 unused SQ CQE's