net: fix percpu memory leaks

This patch fixes following problems :

1) percpu_counter_init() can return an error, therefore
  init_frag_mem_limit() must propagate this error so that
  inet_frags_init_net() can do the same up to its callers.

2) If ip[46]_frags_ns_ctl_register() fail, we must unwind
   properly and free the percpu_counter.

Without this fix, we leave freed object in percpu_counters
global list (if CONFIG_HOTPLUG_CPU) leading to crashes.

This bug was detected by KASAN and syzkaller tool
(http://github.com/google/syzkaller)

Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 53eead2da74324b47ef8c772663f9bcb4fd1d0e1..ac42bbb37b2dd5ca16bee092c3fc4481667f8bf2 100644 (file)
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -108,7 +108,15 @@ struct inet_frags {
 int inet_frags_init(struct inet_frags *);
 void inet_frags_fini(struct inet_frags *);
 
-void inet_frags_init_net(struct netns_frags *nf);
+static inline int inet_frags_init_net(struct netns_frags *nf)
+{
+       return percpu_counter_init(&nf->mem, 0, GFP_KERNEL);
+}
+static inline void inet_frags_uninit_net(struct netns_frags *nf)
+{
+       percpu_counter_destroy(&nf->mem);
+}
+
 void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f);
 
 void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
@@ -154,11 +162,6 @@ static inline void add_frag_mem_limit(struct netns_frags *nf, int i)
        __percpu_counter_add(&nf->mem, i, frag_percpu_counter_batch);
 }
 
-static inline void init_frag_mem_limit(struct netns_frags *nf)
-{
-       percpu_counter_init(&nf->mem, 0, GFP_KERNEL);
-}
-
 static inline unsigned int sum_frag_mem_limit(struct netns_frags *nf)
 {
        unsigned int res;

diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index 12e8cf4bda9ff9e6b9f7744635bf159421ae8a5c..6b437e8760d314c5314cc1deb2d5d13dff0f2ec8 100644 (file)
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -580,14 +580,19 @@ static int __net_init lowpan_frags_init_net(struct net *net)
 {
        struct netns_ieee802154_lowpan *ieee802154_lowpan =
                net_ieee802154_lowpan(net);
+       int res;
 
        ieee802154_lowpan->frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
        ieee802154_lowpan->frags.low_thresh = IPV6_FRAG_LOW_THRESH;
        ieee802154_lowpan->frags.timeout = IPV6_FRAG_TIMEOUT;
 
-       inet_frags_init_net(&ieee802154_lowpan->frags);
-
-       return lowpan_frags_ns_sysctl_register(net);
+       res = inet_frags_init_net(&ieee802154_lowpan->frags);
+       if (res)
+               return res;
+       res = lowpan_frags_ns_sysctl_register(net);
+       if (res)
+               inet_frags_uninit_net(&ieee802154_lowpan->frags);
+       return res;
 }
 
 static void __net_exit lowpan_frags_exit_net(struct net *net)

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index d0a7c0319e3d1b1b73f828717062b6fbbd3be27d..fe144dae7372dcfa3e0c5dc34f66ce9cfde2e7a3 100644 (file)
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -209,12 +209,6 @@ int inet_frags_init(struct inet_frags *f)
 }
 EXPORT_SYMBOL(inet_frags_init);
 
-void inet_frags_init_net(struct netns_frags *nf)
-{
-       init_frag_mem_limit(nf);
-}
-EXPORT_SYMBOL(inet_frags_init_net);
-
 void inet_frags_fini(struct inet_frags *f)
 {
        cancel_work_sync(&f->frags_work);

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 5482745d5d6843b8a3da1b2845bba0030e854944..1fe55ae817818abf9f10fa4c06a222476d3d3c45 100644 (file)
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -839,6 +839,8 @@ static void __init ip4_frags_ctl_register(void)
 
 static int __net_init ipv4_frags_init_net(struct net *net)
 {
+       int res;
+
        /* Fragment cache limits.
         *
         * The fragment memory accounting code, (tries to) account for
@@ -862,9 +864,13 @@ static int __net_init ipv4_frags_init_net(struct net *net)
         */
        net->ipv4.frags.timeout = IP_FRAG_TIME;
 
-       inet_frags_init_net(&net->ipv4.frags);
-
-       return ip4_frags_ns_ctl_register(net);
+       res = inet_frags_init_net(&net->ipv4.frags);
+       if (res)
+               return res;
+       res = ip4_frags_ns_ctl_register(net);
+       if (res)
+               inet_frags_uninit_net(&net->ipv4.frags);
+       return res;
 }
 
 static void __net_exit ipv4_frags_exit_net(struct net *net)

diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 99610547fccc1549774cb1c22cfa82ba22ae9a10..d5efeb87350e7fc8643962036c0b26cfe471cdc4 100644 (file)
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -648,12 +648,18 @@ EXPORT_SYMBOL_GPL(nf_ct_frag6_consume_orig);
 
 static int nf_ct_net_init(struct net *net)
 {
+       int res;
+
        net->nf_frag.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
        net->nf_frag.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
        net->nf_frag.frags.timeout = IPV6_FRAG_TIMEOUT;
-       inet_frags_init_net(&net->nf_frag.frags);
-
-       return nf_ct_frag6_sysctl_register(net);
+       res = inet_frags_init_net(&net->nf_frag.frags);
+       if (res)
+               return res;
+       res = nf_ct_frag6_sysctl_register(net);
+       if (res)
+               inet_frags_uninit_net(&net->nf_frag.frags);
+       return res;
 }
 
 static void nf_ct_net_exit(struct net *net)

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index f1159bb76e0a54fb55a3e8e382a6cb80c7a929f9..44e21a03cfc3fff395903d36e8e01a7a3e395afa 100644 (file)
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -706,13 +706,19 @@ static void ip6_frags_sysctl_unregister(void)
 
 static int __net_init ipv6_frags_init_net(struct net *net)
 {
+       int res;
+
        net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
        net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
        net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
 
-       inet_frags_init_net(&net->ipv6.frags);
-
-       return ip6_frags_ns_sysctl_register(net);
+       res = inet_frags_init_net(&net->ipv6.frags);
+       if (res)
+               return res;
+       res = ip6_frags_ns_sysctl_register(net);
+       if (res)
+               inet_frags_uninit_net(&net->ipv6.frags);
+       return res;
 }
 
 static void __net_exit ipv6_frags_exit_net(struct net *net)