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: 6d7b857d54 ("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>
This commit is contained in:
Eric Dumazet 2015-11-02 09:03:11 -08:00 committed by David S. Miller
parent c451113291
commit 1d6119baf0
6 changed files with 44 additions and 24 deletions

View File

@ -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;

View File

@ -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)

View File

@ -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);

View File

@ -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)

View File

@ -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)

View File

@ -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)