From 297dbde19cf6a0ccb6fd4396c6220a5912ed61e8 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 7 Dec 2015 17:38:51 -0500 Subject: netprio_cgroup: limit the maximum css->id to USHRT_MAX netprio builds per-netdev contiguous priomap array which is indexed by css->id. The array is allocated using kzalloc() effectively limiting the maximum ID supported to some thousand range. This patch caps the maximum supported css->id to USHRT_MAX which should be way above what is actually useable. This allows reducing sock->sk_cgrp_prioidx to u16 from u32. The freed up part will be used to overload the cgroup related fields. sock->sk_cgrp_prioidx's position is swapped with sk_mark so that the two cgroup related fields are adjacent. Signed-off-by: Tejun Heo Acked-by: Daniel Wagner Cc: Daniel Borkmann CC: Neil Horman Signed-off-by: David S. Miller --- net/core/netprio_cgroup.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'net/core') diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index cbd0a199bf52..2b9159b7a28a 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -27,6 +27,12 @@ #include +/* + * netprio allocates per-net_device priomap array which is indexed by + * css->id. Limiting css ID to 16bits doesn't lose anything. + */ +#define NETPRIO_ID_MAX USHRT_MAX + #define PRIOMAP_MIN_SZ 128 /* @@ -144,6 +150,9 @@ static int cgrp_css_online(struct cgroup_subsys_state *css) struct net_device *dev; int ret = 0; + if (css->id > NETPRIO_ID_MAX) + return -ENOSPC; + if (!parent_css) return 0; -- cgit v1.2.3