This is a note to let you know that I've just added the patch titled net: ll_temac: Fix TX BD buffer overwrite to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-ll_temac-fix-tx-bd-buffer-overwrite.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c364df2489b8ef2f5e3159b1dff1ff1fdb16040d Mon Sep 17 00:00:00 2001 From: Esben Haabendal <esben@xxxxxxxxxx> Date: Fri, 18 Jun 2021 12:52:33 +0200 Subject: net: ll_temac: Fix TX BD buffer overwrite From: Esben Haabendal <esben@xxxxxxxxxx> commit c364df2489b8ef2f5e3159b1dff1ff1fdb16040d upstream. 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@xxxxxxxxxxxxxxx # v5.4+ Signed-off-by: Esben Haabendal <esben@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/xilinx/ll_temac_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/ethernet/xilinx/ll_temac_main.c +++ b/drivers/net/ethernet/xilinx/ll_temac_main.c @@ -846,7 +846,7 @@ temac_start_xmit(struct sk_buff *skb, st 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); Patches currently in stable-queue which might be from esben@xxxxxxxxxx are queue-5.4/net-ll_temac-fix-tx-bd-buffer-overwrite.patch queue-5.4/net-ll_temac-make-sure-to-free-skb-when-it-is-completely-used.patch