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net: fix percpu memory leaks

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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
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15
include/net/inet_frag.h
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;