[PATCH 3.19.y-ckt 162/164] net: fix percpu memory leaks

From: Kamal Mostafa
Date: Wed Dec 02 2015 - 12:02:38 EST


3.19.8-ckt11 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>

commit 1d6119baf0610f813eb9d9580eb4fd16de5b4ceb upstream.

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@xxxxxxxxxx>
Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Acked-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[ kamal: backport to 3.19-stable: rename reassembly.c ]
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
include/net/inet_frag.h | 15 +++++++++------
net/ieee802154/reassembly.c | 11 ++++++++---
net/ipv4/inet_fragment.c | 6 ------
net/ipv4/ip_fragment.c | 12 +++++++++---
net/ipv6/netfilter/nf_conntrack_reasm.c | 12 +++++++++---
net/ipv6/reassembly.c | 12 +++++++++---
6 files changed, 44 insertions(+), 24 deletions(-)

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 3242bfd..b931bbd 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -110,7 +110,15 @@ 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);
@@ -151,11 +159,6 @@ static inline void add_frag_mem_limit(struct inet_frag_queue *q, int i)
__percpu_counter_add(&q->net->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/reassembly.c b/net/ieee802154/reassembly.c
index 9d980ed..d67e4a2 100644
--- a/net/ieee802154/reassembly.c
+++ b/net/ieee802154/reassembly.c
@@ -523,14 +523,19 @@ 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 edc17b9..2c2a6b6 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -220,12 +220,6 @@ 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 0f128f8..439e7de 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -816,6 +816,8 @@ 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
@@ -839,9 +841,13 @@ 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 6f187c8..3bbcb17 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -648,12 +648,18 @@ void nf_ct_frag6_consume_orig(struct sk_buff *skb)

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 d7d70e6..886d1c4 100644
--- 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)
--
1.9.1

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