via-velocity: fix memory corruption when changing the mtu

velocity_rx_refill() only replenishes the descriptor entries which
belong to the CPU. It works great in the Rx path but the driver must
ensure that all the descriptors are freed before velocity_rx_refill()
is used in velocity_change_mtu(). The patch resets the Rx descriptors
in velocity_free_rd_ring().

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/net/via-velocity.c b/drivers/net/via-velocity.c
index c2d5907dc8e0..ed1f837c8fda 100644
--- a/drivers/net/via-velocity.c
+++ b/drivers/net/via-velocity.c
@@ -1106,6 +1106,9 @@ static void velocity_free_rd_ring(struct velocity_info *vptr)
 
         for (i = 0; i < vptr->options.numrx; i++) {
                 struct velocity_rd_info *rd_info = &(vptr->rd_info[i]);
+                struct rx_desc *rd = vptr->rd_ring + i;
+
+                memset(rd, 0, sizeof(*rd));
 
                 if (!rd_info->skb)
                         continue;