netprio_cgroup: fix an off-by-one bug
# mount -t cgroup xxx /mnt
# mkdir /mnt/tmp
# cat /mnt/tmp/net_prio.ifpriomap
lo 0
eth0 0
virbr0 0
# echo 'lo 999' > /mnt/tmp/net_prio.ifpriomap
# cat /mnt/tmp/net_prio.ifpriomap
lo 999
eth0 0
virbr0 4101267344
We got weired output, because we exceeded the boundary of the array.
We may even crash the kernel..
Origionally-authored-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 9ae183a..72c6387 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -108,7 +108,7 @@
static void update_netdev_tables(void)
{
struct net_device *dev;
- u32 max_len = atomic_read(&max_prioidx);
+ u32 max_len = atomic_read(&max_prioidx) + 1;
struct netprio_map *map;
rtnl_lock();