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authorTejun Heo <tj@kernel.org>2015-12-07 17:38:51 -0500
committerDavid S. Miller <davem@davemloft.net>2015-12-08 22:02:33 -0500
commit297dbde19cf6a0ccb6fd4396c6220a5912ed61e8 (patch)
treed1b65de60b8d8adfd2f84542cd59d9ed61f12c6b /net/core
parentbc9b145a092aca91a7f6ef40cdb3628b6ada7ec9 (diff)
downloadlinux-297dbde19cf6a0ccb6fd4396c6220a5912ed61e8.tar.bz2
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 <tj@kernel.org> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Daniel Borkmann <daniel@iogearbox.net> CC: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/netprio_cgroup.c9
1 files changed, 9 insertions, 0 deletions
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 <linux/fdtable.h>
+/*
+ * 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;