Just as the initial check, we need to ensure num_frag+1 buffers available, as that is the number of buffers we are going to use.
This fixes a buffer overflow, which might be seen during heavy network load. Complete lockup of TEMAC was reproducible within about 10 minutes of a particular load.
Fixes: 84823ff80f74 ("net: ll_temac: Fix race condition causing TX hang") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Esben Haabendal esben@geanix.com --- drivers/net/ethernet/xilinx/ll_temac_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c index 9797aa3221d1..cc482ee36501 100644 --- a/drivers/net/ethernet/xilinx/ll_temac_main.c +++ b/drivers/net/ethernet/xilinx/ll_temac_main.c @@ -861,7 +861,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev) smp_mb();
/* Space might have just been freed - check again */ - if (temac_check_tx_bd_space(lp, num_frag)) + if (temac_check_tx_bd_space(lp, num_frag + 1)) return NETDEV_TX_BUSY;
netif_wake_queue(ndev);