bonding: fix a buffer overflow in bonding_show_queue_id.

The test for buffer overflow ensures we have room for 6 more bytes.
sprintf, called with %s:%d, slave->dev->name, slave->queue_id may yield
far more than 6 bytes.

The correct test is res > (PAGE_SIZE - IFNAMSIZ - 6) .

Signed-off-by: Nicolas de Pesloüan <nicolas.2p.debian@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index f9a034361a8e..1a9976487099 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -1427,8 +1427,8 @@ static ssize_t bonding_show_queue_id(struct device *d,
 
         read_lock(&bond->lock);
         bond_for_each_slave(bond, slave, i) {
-                if (res > (PAGE_SIZE - 6)) {
-                        /* not enough space for another interface name */
+                if (res > (PAGE_SIZE - IFNAMSIZ - 6)) {
+                        /* not enough space for another interface_name:queue_id pair */
                         if ((PAGE_SIZE - res) > 10)
                                 res = PAGE_SIZE - 10;
                         res += sprintf(buf + res, "++more++ ");