From 74028c9c22fd8f25a6571cfe62b7a89f310500e8 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 27 May 2020 21:48:30 +0300 Subject: [PATCH] airo: Fix read overflows sending packets commit 11e7a91994c29da96d847f676be023da6a2c1359 upstream. The problem is that we always copy a minimum of ETH_ZLEN (60) bytes from skb->data even when skb->len is less than ETH_ZLEN so it leads to a read overflow. The fix is to pad skb->data to at least ETH_ZLEN bytes. Cc: Reported-by: Hu Jiahui Signed-off-by: Dan Carpenter Reviewed-by: Eric Dumazet Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20200527184830.GA1164846@mwanda Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/cisco/airo.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/net/wireless/cisco/airo.c b/drivers/net/wireless/cisco/airo.c index c4c8f1b62e1e..da0d3834b5f0 100644 --- a/drivers/net/wireless/cisco/airo.c +++ b/drivers/net/wireless/cisco/airo.c @@ -1925,6 +1925,10 @@ static netdev_tx_t mpi_start_xmit(struct sk_buff *skb, airo_print_err(dev->name, "%s: skb == NULL!",__func__); return NETDEV_TX_OK; } + if (skb_padto(skb, ETH_ZLEN)) { + dev->stats.tx_dropped++; + return NETDEV_TX_OK; + } npacks = skb_queue_len (&ai->txq); if (npacks >= MAXTXQ - 1) { @@ -2127,6 +2131,10 @@ static netdev_tx_t airo_start_xmit(struct sk_buff *skb, airo_print_err(dev->name, "%s: skb == NULL!", __func__); return NETDEV_TX_OK; } + if (skb_padto(skb, ETH_ZLEN)) { + dev->stats.tx_dropped++; + return NETDEV_TX_OK; + } /* Find a vacant FID */ for( i = 0; i < MAX_FIDS / 2 && (fids[i] & 0xffff0000); i++ ); @@ -2201,6 +2209,10 @@ static netdev_tx_t airo_start_xmit11(struct sk_buff *skb, airo_print_err(dev->name, "%s: skb == NULL!", __func__); return NETDEV_TX_OK; } + if (skb_padto(skb, ETH_ZLEN)) { + dev->stats.tx_dropped++; + return NETDEV_TX_OK; + } /* Find a vacant FID */ for( i = MAX_FIDS / 2; i < MAX_FIDS && (fids[i] & 0xffff0000); i++ );