Commit 297dbde1 authored by Tejun Heo's avatar Tejun Heo Committed by David S. Miller
Browse files

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: default avatarTejun Heo <>
Acked-by: default avatarDaniel Wagner <>
Cc: Daniel Borkmann <>
CC: Neil Horman <>
Signed-off-by: default avatarDavid S. Miller <>
parent bc9b145a
......@@ -288,7 +288,6 @@ struct cg_proto;
* @sk_ack_backlog: current listen backlog
* @sk_max_ack_backlog: listen backlog set in listen()
* @sk_priority: %SO_PRIORITY setting
* @sk_cgrp_prioidx: socket group's priority map index
* @sk_type: socket type (%SOCK_STREAM, etc)
* @sk_protocol: which protocol this socket belongs in this network family
* @sk_peer_pid: &struct pid for this socket's peer
......@@ -309,6 +308,7 @@ struct cg_proto;
* @sk_send_head: front of stuff to transmit
* @sk_security: used by security modules
* @sk_mark: generic packet mark
* @sk_cgrp_prioidx: socket group's priority map index
* @sk_classid: this socket's cgroup classid
* @sk_cgrp: this socket's cgroup-specific proto data
* @sk_write_pending: a write to stream socket waits to start
......@@ -425,9 +425,7 @@ struct sock {
u32 sk_ack_backlog;
u32 sk_max_ack_backlog;
__u32 sk_priority;
__u32 sk_cgrp_prioidx;
__u32 sk_mark;
struct pid *sk_peer_pid;
const struct cred *sk_peer_cred;
long sk_rcvtimeo;
......@@ -445,7 +443,9 @@ struct sock {
void *sk_security;
__u32 sk_mark;
u16 sk_cgrp_prioidx;
u32 sk_classid;
......@@ -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 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;
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