Messages in this thread Patch in this message | | | From | Gao feng <> | Subject | [PATCH v2] cgroup: fix panic in netprio_cgroup | Date | Thu, 5 Jul 2012 17:28:40 +0800 |
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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: Gao feng <gaofeng@cn.fujitsu.com> --- net/core/netprio_cgroup.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index 5b8aa2f..aa907ed 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -49,8 +49,9 @@ static int get_prioidx(u32 *prio) return -ENOSPC; } set_bit(prioidx, prioidx_map); + if (atomic_read(&max_prioidx) < prioidx) + atomic_set(&max_prioidx, prioidx); spin_unlock_irqrestore(&prioidx_map_lock, flags); - atomic_set(&max_prioidx, prioidx); *prio = prioidx; return 0; } -- 1.7.7.6
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