[v2.1] davinci_emac: fix kernel oops when changing MAC address while interface is down

Commit Message

Pablo Bitton July 7, 2009, 6:10 a.m. UTC

Check that network interface is running before changing its MAC address.
Otherwise, rxch is accessed when it's NULL - causing a kernel oops.
Moreover, check that the new MAC address is valid.

Signed-off-by: Pablo Bitton <[e-mail]>
Signed-off-by: Chaithrika U S <[e-mail]>
Tested-by: Chaithrika U S <[e-mail]>
[tested on DM6467 EVM]

---
 drivers/net/davinci_emac.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

Comments

Pablo Bitton July 7, 2009, 6:09 a.m. UTC | #1

Hi,

I've resubmitted this patch since my email client has corrupted
 the v2 patch, turning TAB characters into spaces.

Hopefully, this won't happen again.

On Tue, Jul 7, 2009 at 9:10 AM, Pablo Bitton<[e-mail]> wrote:
> Check that network interface is running before changing its MAC address.
> Otherwise, rxch is accessed when it's NULL - causing a kernel oops.
> Moreover, check that the new MAC address is valid.
>
> Signed-off-by: Pablo Bitton <[e-mail]>
> Signed-off-by: Chaithrika U S <[e-mail]>
> Tested-by: Chaithrika U S <[e-mail]>
> [tested on DM6467 EVM]
>
> ---
>  drivers/net/davinci_emac.c |   12 ++++++++++--
>  1 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/davinci_emac.c b/drivers/net/davinci_emac.c
> index cf689a0..dddb2b9 100644
> --- a/drivers/net/davinci_emac.c
> +++ b/drivers/net/davinci_emac.c
> @@ -1821,11 +1821,19 @@ static int emac_dev_setmac_addr(struct net_device *ndev, void *addr)
>        struct sockaddr *sa = addr;
>        DECLARE_MAC_BUF(mac);
>
> +       if (!is_valid_ether_addr(sa->sa_data))
> +               return -EINVAL;
> +
>        /* Store mac addr in priv and rx channel and set it in EMAC hw */
>        memcpy(priv->mac_addr, sa->sa_data, ndev->addr_len);
> -       memcpy(rxch->mac_addr, sa->sa_data, ndev->addr_len);
>        memcpy(ndev->dev_addr, sa->sa_data, ndev->addr_len);
> -       emac_setmac(priv, EMAC_DEF_RX_CH, rxch->mac_addr);
> +
> +       /* If the interface is down - rxch is NULL. */
> +       /* MAC address is configured only after the interface is enabled. */
> +       if (netif_running(ndev)) {
> +               memcpy(rxch->mac_addr, sa->sa_data, ndev->addr_len);
> +               emac_setmac(priv, EMAC_DEF_RX_CH, rxch->mac_addr);
> +       }
>
>        if (netif_msg_drv(priv))
>                dev_notice(emac_dev, "DaVinci EMAC: emac_dev_setmac_addr %s\n",
> --
> 1.5.4.3
>
>
>
>

Patch

diff --git a/drivers/net/davinci_emac.c b/drivers/net/davinci_emac.c
index cf689a0..dddb2b9 100644
--- a/drivers/net/davinci_emac.c
+++ b/drivers/net/davinci_emac.c
@@ -1821,11 +1821,19 @@  static int emac_dev_setmac_addr(struct net_device *ndev, void *addr)
 	struct sockaddr *sa = addr;
 	DECLARE_MAC_BUF(mac);
 
+	if (!is_valid_ether_addr(sa->sa_data))
+		return -EINVAL;
+
 	/* Store mac addr in priv and rx channel and set it in EMAC hw */
 	memcpy(priv->mac_addr, sa->sa_data, ndev->addr_len);
-	memcpy(rxch->mac_addr, sa->sa_data, ndev->addr_len);
 	memcpy(ndev->dev_addr, sa->sa_data, ndev->addr_len);
-	emac_setmac(priv, EMAC_DEF_RX_CH, rxch->mac_addr);
+
+	/* If the interface is down - rxch is NULL. */
+	/* MAC address is configured only after the interface is enabled. */
+	if (netif_running(ndev)) {
+		memcpy(rxch->mac_addr, sa->sa_data, ndev->addr_len);
+		emac_setmac(priv, EMAC_DEF_RX_CH, rxch->mac_addr);
+	}
 
 	if (netif_msg_drv(priv))
 		dev_notice(emac_dev, "DaVinci EMAC: emac_dev_setmac_addr %s\n",