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Commit b761c9b1 authored by Gao feng's avatar Gao feng Committed by David S. Miller
Browse files

cgroup: fix panic in netprio_cgroup 



we set max_prioidx to the first zero bit index of prioidx_map in
function get_prioidx.

So when we delete the low index netprio cgroup and adding a new
netprio cgroup again,the max_prioidx will be set to the low index.

when we set the high index cgroup's net_prio.ifpriomap,the function
write_priomap will call update_netdev_tables to alloc memory which
size is sizeof(struct netprio_map) + sizeof(u32) * (max_prioidx + 1),
so the size of array that map->priomap point to is max_prioidx +1,
which is low than what we actually need.

fix this by adding check in get_prioidx,only set max_prioidx when
max_prioidx low than the new prioidx.

Signed-off-by: default avatarGao feng <gaofeng@cn.fujitsu.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b93984c9

net/core/netprio_cgroup.c

+2 −1
Original line number Diff line number Diff line
@@ -49,8 +49,9 @@ static int get_prioidx(u32 *prio) 
		return -ENOSPC;

	}

	set_bit(prioidx, prioidx_map);

	spin_unlock_irqrestore(&prioidx_map_lock, flags);

	if (atomic_read(&max_prioidx) < prioidx)

		atomic_set(&max_prioidx, prioidx);

	spin_unlock_irqrestore(&prioidx_map_lock, flags);

	*prio = prioidx;

	return 0;

}