Commit a5612ca1 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

net: Fix data-races around sysctl_devconf_inherit_init_net. 



While reading sysctl_devconf_inherit_init_net, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: 856c395c ("net: introduce a knob to control whether to inherit devconf config")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent af67508e

include/linux/netdevice.h

+9 −0
Original line number Diff line number Diff line
@@ -650,6 +650,15 @@ static inline bool net_has_fallback_tunnels(const struct net *net) 
#endif

}



static inline int net_inherit_devconf(void)

{

#if IS_ENABLED(CONFIG_SYSCTL)

	return READ_ONCE(sysctl_devconf_inherit_init_net);

#else

	return 0;

#endif

}



static inline int netdev_queue_numa_node_read(const struct netdev_queue *q)

{

#if defined(CONFIG_XPS) && defined(CONFIG_NUMA)

net/ipv4/devinet.c

+10 −6
Original line number Diff line number Diff line
@@ -2682,23 +2682,27 @@ static __net_init int devinet_init_net(struct net *net) 
#endif



	if (!net_eq(net, &init_net)) {

		if (IS_ENABLED(CONFIG_SYSCTL) &&

		    sysctl_devconf_inherit_init_net == 3) {

		switch (net_inherit_devconf()) {

		case 3:

			/* copy from the current netns */

			memcpy(all, current->nsproxy->net_ns->ipv4.devconf_all,

			       sizeof(ipv4_devconf));

			memcpy(dflt,

			       current->nsproxy->net_ns->ipv4.devconf_dflt,

			       sizeof(ipv4_devconf_dflt));

		} else if (!IS_ENABLED(CONFIG_SYSCTL) ||

			   sysctl_devconf_inherit_init_net != 2) {

			/* inherit == 0 or 1: copy from init_net */

			break;

		case 0:

		case 1:

			/* copy from init_net */

			memcpy(all, init_net.ipv4.devconf_all,

			       sizeof(ipv4_devconf));

			memcpy(dflt, init_net.ipv4.devconf_dflt,

			       sizeof(ipv4_devconf_dflt));

			break;

		case 2:

			/* use compiled values */

			break;

		}

		/* else inherit == 2: use compiled values */

	}



#ifdef CONFIG_SYSCTL

net/ipv6/addrconf.c

+2 −3
Original line number Diff line number Diff line
@@ -7162,9 +7162,8 @@ static int __net_init addrconf_init_net(struct net *net) 
	if (!dflt)

		goto err_alloc_dflt;



	if (IS_ENABLED(CONFIG_SYSCTL) &&

	    !net_eq(net, &init_net)) {

		switch (sysctl_devconf_inherit_init_net) {

	if (!net_eq(net, &init_net)) {

		switch (net_inherit_devconf()) {

		case 1:  /* copy from init_net */

			memcpy(all, init_net.ipv6.devconf_all,

			       sizeof(ipv6_devconf));