From 1d6119baf0610f813eb9d9580eb4fd16de5b4ceb Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 2 Nov 2015 09:03:11 -0800 Subject: [PATCH] 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 Reported-by: Dmitry Vyukov Cc: Hannes Frederic Sowa Cc: Jesper Dangaard Brouer Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- include/net/inet_frag.h | 15 +++++++++------ net/ieee802154/6lowpan/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 53eead2da743..ac42bbb37b2d 100644 --- 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 12e8cf4bda9f..6b437e8760d3 100644 --- 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 d0a7c0319e3d..fe144dae7372 100644 --- 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 5482745d5d68..1fe55ae81781 100644 --- 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 99610547fccc..d5efeb87350e 100644 --- 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 f1159bb76e0a..44e21a03cfc3 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) -- 2.20.1