From c122e14df2d64311d1f0c0bbf4d8f42a7a8baf41 Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Fri, 30 Jun 2017 13:08:08 +0300 Subject: [PATCH] net: convert net.passive from atomic_t to refcount_t refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller --- include/net/net_namespace.h | 3 ++- net/core/net-sysfs.c | 2 +- net/core/net_namespace.c | 4 ++-- 3 files changed, 5 insertions(+), 4 deletions(-) diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index a24a57593202..31a2b51bef2c 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -5,6 +5,7 @@ #define __NET_NET_NAMESPACE_H #include +#include #include #include #include @@ -46,7 +47,7 @@ struct netns_ipvs; #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) struct net { - atomic_t passive; /* To decided when the network + refcount_t passive; /* To decided when the network * namespace should be freed. */ atomic_t count; /* To decided when the network diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index fe7e145c543c..b4f9922b6f23 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1448,7 +1448,7 @@ static void *net_grab_current_ns(void) struct net *ns = current->nsproxy->net_ns; #ifdef CONFIG_NET_NS if (ns) - atomic_inc(&ns->passive); + refcount_inc(&ns->passive); #endif return ns; } diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 6a2f41288249..8726d051f31d 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -284,7 +284,7 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) LIST_HEAD(net_exit_list); atomic_set(&net->count, 1); - atomic_set(&net->passive, 1); + refcount_set(&net->passive, 1); net->dev_base_seq = 1; net->user_ns = user_ns; idr_init(&net->netns_ids); @@ -380,7 +380,7 @@ static void net_free(struct net *net) void net_drop_ns(void *p) { struct net *ns = p; - if (ns && atomic_dec_and_test(&ns->passive)) + if (ns && refcount_dec_and_test(&ns->passive)) net_free(ns); } -- 2.20.1