[PATCH] net: ne2k-pci: fix missing residual byte in block output for 32-bit IO

[PATCH] net: ne2k-pci: fix missing residual byte in block output for 32-bit IO

[Titouan Ameline de Cadeville]

ne2k_pci_block_output() handles residual bytes after the main outsl()
loop when the transfer count is not a multiple of 4. It correctly
handles the 2-byte residual case with outw(),  but is missingg the
1 byte residual case. This means for packets where count % 4 == 1 or
count % 4 == 3,  the final byte is never written to the NIC's data
port.

In practice, this is masked by the count being rounded up to a 4-byte
boundary earlier in the function for ONLY_32BIT_IO cards, but that
rounding itself causes a little information leak by sending
uninitialized kernel buffer bytes on the wire

Add the missing outb() call for the odd byte case, mirroring what
ne2k_pci_block_input() already does correctly.

Signed-off-by: Titouan Ameline de Cadeville <titouan.ameline@gmail.com>
---
 drivers/net/ethernet/8390/ne2k-pci.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/8390/ne2k-pci.c b/drivers/net/ethernet/8390/ne2k-pci.c
index 1a34da07c0db..1bd5b94b5d22 100644
--- a/drivers/net/ethernet/8390/ne2k-pci.c
+++ b/drivers/net/ethernet/8390/ne2k-pci.c
@@ -632,6 +632,8 @@ static void ne2k_pci_block_output(struct net_device *dev, int count,
 				outw(le16_to_cpu(*b++), NE_BASE + NE_DATAPORT);
 				buf = (char *)b;
 			}
+			if (count & 1)
+				outb(*buf, NE_BASE + NE_DATAPORT);
 		}
 	}
 
-- 
2.44.2