This is a note to let you know that I've just added the patch titled

net: cdc_ncm: Fix TX zero padding

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: net-cdc_ncm-fix-tx-zero-padding.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Mon Apr 9 17:09:24 CEST 2018

From: Jim Baxter jim_baxter@mentor.com Date: Mon, 8 May 2017 13:49:57 +0100 Subject: net: cdc_ncm: Fix TX zero padding

From: Jim Baxter jim_baxter@mentor.com

[ Upstream commit aeca3a77b1e0ed06a095933b89c86aed007383eb ]

The zero padding that is added to NTB's does not zero the memory correctly. This is because the skb_put modifies the value of skb_out->len which results in the memset command not setting any memory to zero as (ctx->tx_max - skb_out->len) == 0.

I have resolved this by storing the size of the memory to be zeroed before the skb_put and using this in the memset call.

Signed-off-by: Jim Baxter jim_baxter@mentor.com Reviewed-by: Bjørn Mork bjorn@mork.no Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/usb/cdc_ncm.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)

--- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -1118,6 +1118,7 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev u16 n = 0, index, ndplen; u8 ready2send = 0; u32 delayed_ndp_size; + size_t padding_count;

/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated * accordingly. Otherwise, we should check here. @@ -1274,11 +1275,13 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev * a ZLP after full sized NTBs. */ if (!(dev->driver_info->flags & FLAG_SEND_ZLP) && - skb_out->len > ctx->min_tx_pkt) - memset(skb_put(skb_out, ctx->tx_max - skb_out->len), 0, - ctx->tx_max - skb_out->len); - else if (skb_out->len < ctx->tx_max && (skb_out->len % dev->maxpacket) == 0) + skb_out->len > ctx->min_tx_pkt) { + padding_count = ctx->tx_max - skb_out->len; + memset(skb_put(skb_out, padding_count), 0, padding_count); + } else if (skb_out->len < ctx->tx_max && + (skb_out->len % dev->maxpacket) == 0) { *skb_put(skb_out, 1) = 0; /* force short packet */ + }

/* set final frame length */ nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;

Patches currently in stable-queue which might be from jim_baxter@mentor.com are

queue-4.9/net-cdc_ncm-fix-tx-zero-padding.patch