From: madhuparnabhowmik10@gmail.com
To: davem@davemloft.net, kuznet@ms2.inr.ac.ru,
yoshfuji@linux-ipv6.org, kuba@kernel.org, kaber@trash.net
Cc: paulmck@kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>,
cai@lca.pw, joel@joelfernandes.org,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: [Linux-kernel-mentees] [PATCH net v2] ipv6: Fix suspicious RCU usage warning in ip6mr
Date: Sat, 16 May 2020 13:15:15 +0530 [thread overview]
Message-ID: <20200516074515.13745-1-madhuparnabhowmik10@gmail.com> (raw)
From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
This patch fixes the following warning:
=============================
WARNING: suspicious RCU usage
5.7.0-rc4-next-20200507-syzkaller #0 Not tainted
-----------------------------
net/ipv6/ip6mr.c:124 RCU-list traversed in non-reader section!!
ipmr_new_table() returns an existing table, but there is no table at
init. Therefore the condition: either holding rtnl or the list is empty
is used.
Fixes: d1db275dd3f6e ("ipv6: ip6mr: support multiple tables")
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
---
v2:
- Add correct fixes tag
- Fix line over 80 chars
net/ipv6/ip6mr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 65a54d74acc1..1e223e26f079 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -98,7 +98,8 @@ static void ipmr_expire_process(struct timer_list *t);
#ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
#define ip6mr_for_each_table(mrt, net) \
list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list, \
- lockdep_rtnl_is_held())
+ lockdep_rtnl_is_held() || \
+ list_empty(&net->ipv6.mr6_tables))
static struct mr_table *ip6mr_mr_table_iter(struct net *net,
struct mr_table *mrt)
--
2.17.1
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next reply other threads:[~2020-05-16 7:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-16 7:45 madhuparnabhowmik10 [this message]
2020-05-16 20:43 ` [Linux-kernel-mentees] [PATCH net v2] ipv6: Fix suspicious RCU usage warning in ip6mr David Miller
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