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-rw-r--r--include/linux/netdevice.h4
-rw-r--r--net/core/dev.c13
2 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 136ae6bbe81e..fbdf923af4d3 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1506,6 +1506,8 @@ enum netdev_priv_flags {
* @if_port: Selectable AUI, TP, ...
* @dma: DMA channel
* @mtu: Interface MTU value
+ * @min_mtu: Interface Minimum MTU value
+ * @max_mtu: Interface Maximum MTU value
* @type: Interface hardware type
* @hard_header_len: Maximum hardware header length.
*
@@ -1726,6 +1728,8 @@ struct net_device {
unsigned char dma;
unsigned int mtu;
+ unsigned int min_mtu;
+ unsigned int max_mtu;
unsigned short type;
unsigned short hard_header_len;
diff --git a/net/core/dev.c b/net/core/dev.c
index f1fe26f66458..f376639e8774 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6499,9 +6499,18 @@ int dev_set_mtu(struct net_device *dev, int new_mtu)
if (new_mtu == dev->mtu)
return 0;
- /* MTU must be positive. */
- if (new_mtu < 0)
+ /* MTU must be positive, and in range */
+ if (new_mtu < 0 || new_mtu < dev->min_mtu) {
+ net_err_ratelimited("%s: Invalid MTU %d requested, hw min %d\n",
+ dev->name, new_mtu, dev->min_mtu);
return -EINVAL;
+ }
+
+ if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
+ net_err_ratelimited("%s: Invalid MTU %d requested, hw max %d\n",
+ dev->name, new_mtu, dev->min_mtu);
+ return -EINVAL;
+ }
if (!netif_device_present(dev))
return -ENODEV;