From 227b60f5102cda4e4ab792b526a59c8cb20cd9f8 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Wed, 10 Oct 2007 17:30:46 -0700 Subject: [INET]: local port range robustness Expansion of original idea from Denis V. Lunev Add robustness and locking to the local_port_range sysctl. 1. Enforce that low < high when setting. 2. Use seqlock to ensure atomic update. The locking might seem like overkill, but there are cases where sysadmin might want to change value in the middle of a DoS attack. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/infiniband/core/cma.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 9ffb9987450..2e641b255db 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -1866,13 +1866,14 @@ err1: static int cma_alloc_any_port(struct idr *ps, struct rdma_id_private *id_priv) { struct rdma_bind_list *bind_list; - int port, ret; + int port, ret, low, high; bind_list = kzalloc(sizeof *bind_list, GFP_KERNEL); if (!bind_list) return -ENOMEM; retry: + /* FIXME: add proper port randomization per like inet_csk_get_port */ do { ret = idr_get_new_above(ps, bind_list, next_port, &port); } while ((ret == -EAGAIN) && idr_pre_get(ps, GFP_KERNEL)); @@ -1880,18 +1881,19 @@ retry: if (ret) goto err1; - if (port > sysctl_local_port_range[1]) { - if (next_port != sysctl_local_port_range[0]) { + inet_get_local_port_range(&low, &high); + if (port > high) { + if (next_port != low) { idr_remove(ps, port); - next_port = sysctl_local_port_range[0]; + next_port = low; goto retry; } ret = -EADDRNOTAVAIL; goto err2; } - if (port == sysctl_local_port_range[1]) - next_port = sysctl_local_port_range[0]; + if (port == high) + next_port = low; else next_port = port + 1; @@ -2769,12 +2771,12 @@ static void cma_remove_one(struct ib_device *device) static int cma_init(void) { - int ret; + int ret, low, high; get_random_bytes(&next_port, sizeof next_port); - next_port = ((unsigned int) next_port % - (sysctl_local_port_range[1] - sysctl_local_port_range[0])) + - sysctl_local_port_range[0]; + inet_get_local_port_range(&low, &high); + next_port = ((unsigned int) next_port % (high - low)) + low; + cma_wq = create_singlethread_workqueue("rdma_cm"); if (!cma_wq) return -ENOMEM; -- cgit v1.2.3