Commit ac1a1de3 authored by Ralf Baechle's avatar Ralf Baechle Committed by David S. Miller

NET: NETROM: When adding a route verify length of mnemonic string.

struct nr_route_struct's mnemonic permits a string of up to 7 bytes to be
used.  If userland passes a not zero terminated string to the kernel adding
a node to the routing table might result in the kernel attempting to read
copy a too long string.

Mnemonic is part of the NET/ROM routing protocol; NET/ROM routing table
updates only broadcast 6 bytes.  The 7th byte in the mnemonic array exists
only as a \0 termination character for the kernel code's convenience.

Fixed by rejecting mnemonic strings that have no terminating \0 in the first
7 characters.  Do this test only NETROM_NODE to avoid breaking NETROM_NEIGH
where userland might passing an uninitialized mnemonic field.

Initial patch by Dan Carpenter <dan.carpenter@oracle.com>.
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Walter Harms <wharms@bfs.de>
Cc: Thomas Osterried <thomas@osterried.de>
Acked-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent be639ac6
......@@ -678,6 +678,11 @@ int nr_rt_ioctl(unsigned int cmd, void __user *arg)
}
switch (nr_route.type) {
case NETROM_NODE:
if (strnlen(nr_route.mnemonic, 7) == 7) {
ret = -EINVAL;
break;
}
ret = nr_add_node(&nr_route.callsign,
nr_route.mnemonic,
&nr_route.neighbour,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment