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authorDan Carpenter <dan.carpenter@oracle.com>2014-07-17 13:50:45 +0300
committerDavid S. Miller <davem@davemloft.net>2014-07-17 16:47:50 -0700
commita28d0e873d2899bd750ae495f84fe9c1a2f53809 (patch)
treec298871f2dfa4dc8f93e0f2928aa844b1cda20f1 /drivers/net/wan
parentcc25eaae238ddd693aa5eaa73e565d8ff4915f6e (diff)
wan/x25_asy: integer overflow in x25_asy_change_mtu()
If "newmtu * 2 + 4" is too large then it can cause an integer overflow leading to memory corruption. Eric Dumazet suggests that 65534 is a reasonable upper limit. Btw, "newmtu" is not allowed to be a negative number because of the check in dev_set_mtu(), so that's ok. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/wan')
-rw-r--r--drivers/net/wan/x25_asy.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c
index 5895f1978691..fa9fdfa128c1 100644
--- a/drivers/net/wan/x25_asy.c
+++ b/drivers/net/wan/x25_asy.c
@@ -122,8 +122,12 @@ static int x25_asy_change_mtu(struct net_device *dev, int newmtu)
{
struct x25_asy *sl = netdev_priv(dev);
unsigned char *xbuff, *rbuff;
- int len = 2 * newmtu;
+ int len;
+ if (newmtu > 65534)
+ return -EINVAL;
+
+ len = 2 * newmtu;
xbuff = kmalloc(len + 4, GFP_ATOMIC);
rbuff = kmalloc(len + 4, GFP_ATOMIC);