From 7efb75b11480c46077b44df70aa30d375bf761be Mon Sep 17 00:00:00 2001 From: Simon Goldschmidt Date: Sat, 17 Nov 2018 10:24:42 +0100 Subject: [PATCH] net: designware: clear padding bytes Short frames are padded to the minimum allowed size of 60 bytes. However, the designware driver sends old data in these padding bytes. It is common practice to zero out these padding bytes ro prevent leaking memory contents to other hosts. Fix the padding code to zero out the padded bytes at the end. Tested on socfpga gen5. Signed-off-by: Simon Goldschmidt Acked-by: Joe Hershberger --- drivers/net/designware.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/designware.c b/drivers/net/designware.c index 01abcc21d2..2c5d9560c5 100644 --- a/drivers/net/designware.c +++ b/drivers/net/designware.c @@ -380,9 +380,11 @@ static int _dw_eth_send(struct dw_eth_dev *priv, void *packet, int length) return -EPERM; } - length = max(length, ETH_ZLEN); - memcpy((void *)data_start, packet, length); + if (length < ETH_ZLEN) { + memset(&((char *)data_start)[length], 0, ETH_ZLEN - length); + length = ETH_ZLEN; + } /* Flush data to be sent */ flush_dcache_range(data_start, data_end); -- 2.39.2