* [Patch net] xt_RATEEST: acquire xt_rateest_mutex for hash insert
@ 2018-02-01 0:26 Cong Wang
2018-02-01 1:44 ` Eric Dumazet
0 siblings, 1 reply; 4+ messages in thread
From: Cong Wang @ 2018-02-01 0:26 UTC (permalink / raw)
To: netdev; +Cc: netfilter-devel, Cong Wang, Pablo Neira Ayuso
rateest_hash is supposed to be protected by xt_rateest_mutex.
Reported-by: <syzbot+5cb189720978275e4c75@syzkaller.appspotmail.com>
Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
net/netfilter/xt_RATEEST.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
index 498b54fd04d7..83ec3a282755 100644
--- a/net/netfilter/xt_RATEEST.c
+++ b/net/netfilter/xt_RATEEST.c
@@ -36,7 +36,9 @@ static void xt_rateest_hash_insert(struct xt_rateest *est)
unsigned int h;
h = xt_rateest_hash(est->name);
+ mutex_lock(&xt_rateest_mutex);
hlist_add_head(&est->list, &rateest_hash[h]);
+ mutex_unlock(&xt_rateest_mutex);
}
struct xt_rateest *xt_rateest_lookup(const char *name)
--
2.13.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [Patch net] xt_RATEEST: acquire xt_rateest_mutex for hash insert
2018-02-01 0:26 [Patch net] xt_RATEEST: acquire xt_rateest_mutex for hash insert Cong Wang
@ 2018-02-01 1:44 ` Eric Dumazet
2018-02-01 21:50 ` Cong Wang
0 siblings, 1 reply; 4+ messages in thread
From: Eric Dumazet @ 2018-02-01 1:44 UTC (permalink / raw)
To: Cong Wang, netdev; +Cc: netfilter-devel, Pablo Neira Ayuso
On Wed, 2018-01-31 at 16:26 -0800, Cong Wang wrote:
> rateest_hash is supposed to be protected by xt_rateest_mutex.
>
> Reported-by: <syzbot+5cb189720978275e4c75@syzkaller.appspotmail.com>
> Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
> Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> ---
> net/netfilter/xt_RATEEST.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
> index 498b54fd04d7..83ec3a282755 100644
> --- a/net/netfilter/xt_RATEEST.c
> +++ b/net/netfilter/xt_RATEEST.c
> @@ -36,7 +36,9 @@ static void xt_rateest_hash_insert(struct xt_rateest *est)
> unsigned int h;
>
> h = xt_rateest_hash(est->name);
> + mutex_lock(&xt_rateest_mutex);
> hlist_add_head(&est->list, &rateest_hash[h]);
> + mutex_unlock(&xt_rateest_mutex);
> }
We probably should make this module netns aware, otherwise bad things
will happen.
(It seems multiple threads could run, so getting the mutex twice
(xt_rateest_lookup then xt_rateest_hash_insert() is racy)
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [Patch net] xt_RATEEST: acquire xt_rateest_mutex for hash insert
2018-02-01 1:44 ` Eric Dumazet
@ 2018-02-01 21:50 ` Cong Wang
2018-02-01 22:36 ` Florian Westphal
0 siblings, 1 reply; 4+ messages in thread
From: Cong Wang @ 2018-02-01 21:50 UTC (permalink / raw)
To: Eric Dumazet
Cc: Linux Kernel Network Developers, netfilter-devel,
Pablo Neira Ayuso
On Wed, Jan 31, 2018 at 5:44 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Wed, 2018-01-31 at 16:26 -0800, Cong Wang wrote:
>> rateest_hash is supposed to be protected by xt_rateest_mutex.
>>
>> Reported-by: <syzbot+5cb189720978275e4c75@syzkaller.appspotmail.com>
>> Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
>> Cc: Pablo Neira Ayuso <pablo@netfilter.org>
>> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
>> ---
>> net/netfilter/xt_RATEEST.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
>> index 498b54fd04d7..83ec3a282755 100644
>> --- a/net/netfilter/xt_RATEEST.c
>> +++ b/net/netfilter/xt_RATEEST.c
>> @@ -36,7 +36,9 @@ static void xt_rateest_hash_insert(struct xt_rateest *est)
>> unsigned int h;
>>
>> h = xt_rateest_hash(est->name);
>> + mutex_lock(&xt_rateest_mutex);
>> hlist_add_head(&est->list, &rateest_hash[h]);
>> + mutex_unlock(&xt_rateest_mutex);
>> }
>
> We probably should make this module netns aware, otherwise bad things
> will happen.
Right, both the lock and the hashtable. I can do it for net-next,
if you don't.
>
> (It seems multiple threads could run, so getting the mutex twice
> (xt_rateest_lookup then xt_rateest_hash_insert() is racy)
Yeah, need to merge these two critical sections.
Thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [Patch net] xt_RATEEST: acquire xt_rateest_mutex for hash insert
2018-02-01 21:50 ` Cong Wang
@ 2018-02-01 22:36 ` Florian Westphal
0 siblings, 0 replies; 4+ messages in thread
From: Florian Westphal @ 2018-02-01 22:36 UTC (permalink / raw)
To: Cong Wang
Cc: Eric Dumazet, Linux Kernel Network Developers, netfilter-devel,
Pablo Neira Ayuso
Cong Wang <xiyou.wangcong@gmail.com> wrote:
> On Wed, Jan 31, 2018 at 5:44 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> > On Wed, 2018-01-31 at 16:26 -0800, Cong Wang wrote:
> >> rateest_hash is supposed to be protected by xt_rateest_mutex.
> >>
> >> Reported-by: <syzbot+5cb189720978275e4c75@syzkaller.appspotmail.com>
> >> Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target")
> >> Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> >> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> >> ---
> >> net/netfilter/xt_RATEEST.c | 2 ++
> >> 1 file changed, 2 insertions(+)
> >>
> >> diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
> >> index 498b54fd04d7..83ec3a282755 100644
> >> --- a/net/netfilter/xt_RATEEST.c
> >> +++ b/net/netfilter/xt_RATEEST.c
> >> @@ -36,7 +36,9 @@ static void xt_rateest_hash_insert(struct xt_rateest *est)
> >> unsigned int h;
> >>
> >> h = xt_rateest_hash(est->name);
> >> + mutex_lock(&xt_rateest_mutex);
> >> hlist_add_head(&est->list, &rateest_hash[h]);
> >> + mutex_unlock(&xt_rateest_mutex);
> >> }
> >
> > We probably should make this module netns aware, otherwise bad things
> > will happen.
>
> Right, both the lock and the hashtable. I can do it for net-next,
> if you don't.
Note that the xtables af mutexes are not per-netns, the race is iptables
vs. ip6tables.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-02-01 0:26 [Patch net] xt_RATEEST: acquire xt_rateest_mutex for hash insert Cong Wang
2018-02-01 1:44 ` Eric Dumazet
2018-02-01 21:50 ` Cong Wang
2018-02-01 22:36 ` Florian Westphal
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