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authorWolfgang Grandegger <wg@grandegger.com>2011-10-07 09:28:14 +0000
committerDavid S. Miller <davem@davemloft.net>2011-10-10 14:31:00 -0400
commita3a4bfde8a271df7ee56fcf31b8d907d50e7f216 (patch)
treea9ef98f3da1e449b0a430705ab8b9abea036467b
parentcdaf557034bb4397b2c86bb424de1788b134f610 (diff)
mscan: too much data copied to CAN frame due to 16 bit accesses
Due to the 16 bit access to mscan registers there's too much data copied to the zero initialized CAN frame when having an odd number of bytes to copy. This patch ensures that only the requested bytes are copied by using an 8 bit access for the remaining byte. Reported-by: Andre Naujoks <nautsch@gmail.com> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/can/mscan/mscan.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c
index 92feac68b66e..4cc6f44c2ba2 100644
--- a/drivers/net/can/mscan/mscan.c
+++ b/drivers/net/can/mscan/mscan.c
@@ -261,11 +261,13 @@ static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
void __iomem *data = &regs->tx.dsr1_0;
u16 *payload = (u16 *)frame->data;
- /* It is safe to write into dsr[dlc+1] */
- for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
+ for (i = 0; i < frame->can_dlc / 2; i++) {
out_be16(data, *payload++);
data += 2 + _MSCAN_RESERVED_DSR_SIZE;
}
+ /* write remaining byte if necessary */
+ if (frame->can_dlc & 1)
+ out_8(data, frame->data[frame->can_dlc - 1]);
}
out_8(&regs->tx.dlr, frame->can_dlc);
@@ -330,10 +332,13 @@ static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
void __iomem *data = &regs->rx.dsr1_0;
u16 *payload = (u16 *)frame->data;
- for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
+ for (i = 0; i < frame->can_dlc / 2; i++) {
*payload++ = in_be16(data);
data += 2 + _MSCAN_RESERVED_DSR_SIZE;
}
+ /* read remaining byte if necessary */
+ if (frame->can_dlc & 1)
+ frame->data[frame->can_dlc - 1] = in_8(data);
}
out_8(&regs->canrflg, MSCAN_RXF);

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