From b17e852f839620fb4d7e45f5f16688d01b5d3dc0 Mon Sep 17 00:00:00 2001
From: Esben Haabendal <esben@geanix.com>
Date: Fri, 18 Jun 2021 12:52:33 +0200
Subject: [PATCH 3/3] net: ll_temac: Fix TX BD buffer overwrite
References: git-fixes
Git-commit: c364df2489b8ef2f5e3159b1dff1ff1fdb16040d
Patch-mainline: v5.13-rc7
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.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 1fbebdeb513f..37ad5a58ee07 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -701,7 +701,7 @@ static int 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);
--
2.16.4