Thread (4 messages) 4 messages, 3 authors, 2011-11-23

Re: [patch] netrom: check that user string is terminated

From: walter harms <hidden>
Date: 2011-11-23 08:22:16
Also in: kernel-janitors, linux-hams


Am 23.11.2011 07:52, schrieb Dan Carpenter:
quoted hunk ↗ jump to hunk
We do an strcpy() of mnemonic in nr_add_node().

Signed-off-by: Dan Carpenter <redacted>
diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c
index 915a87b..e126c48 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -670,6 +670,8 @@ int nr_rt_ioctl(unsigned int cmd, void __user *arg)
 	case SIOCADDRT:
 		if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
 			return -EFAULT;
+		if (strlen(nr_route.mnemonic) >= sizeof(nr_route.mnemonic))
+			return -EINVAL;

I am not sure that it does what you intends.
mnemonic is an array and a  malicious use may fill it upto the last char
causing strlen go beyond. perhaps this may help:
	nr_route.mnemonic[sizeof(nr_route.mnemonic)-1]=0;
this of cause makes the if() redundant.


 		if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
 			return -EINVAL;
while you are here:

	dev = nr_ax25_dev_get(nr_route.device);
	if ( dev == NULL )
		return -EINVAL;
 		if (nr_route.ndigis < 0 || nr_route.ndigis > AX25_MAX_DIGIS) {
if guess "nr_route.ndigis >= AX25_MAX_DIGIS" is intended ?

hope that helps,
 wh
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