lkml.org 
[lkml]   [2022]   [Mar]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.16 045/186] ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()
Date
From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 2d3916f3189172d5c69d33065c3c21119fe539fc ]

While investigating on why a synchronize_net() has been added recently
in ipv6_mc_down(), I found that igmp6_event_query() and igmp6_event_report()
might drop skbs in some cases.

Discussion about removing synchronize_net() from ipv6_mc_down()
will happen in a different thread.

Fixes: f185de28d9ae ("mld: add new workqueues for process mld events")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220303173728.937869-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/net/ndisc.h | 4 ++--
net/ipv6/mcast.c | 32 ++++++++++++--------------------
2 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index 04341d86585de..5e37e58586796 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -487,9 +487,9 @@ int igmp6_late_init(void);
void igmp6_cleanup(void);
void igmp6_late_cleanup(void);

-int igmp6_event_query(struct sk_buff *skb);
+void igmp6_event_query(struct sk_buff *skb);

-int igmp6_event_report(struct sk_buff *skb);
+void igmp6_event_report(struct sk_buff *skb);


#ifdef CONFIG_SYSCTL
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index a8861db52c187..909f937befd71 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1371,27 +1371,23 @@ static void mld_process_v2(struct inet6_dev *idev, struct mld2_query *mld,
}

/* called with rcu_read_lock() */
-int igmp6_event_query(struct sk_buff *skb)
+void igmp6_event_query(struct sk_buff *skb)
{
struct inet6_dev *idev = __in6_dev_get(skb->dev);

- if (!idev)
- return -EINVAL;
-
- if (idev->dead) {
- kfree_skb(skb);
- return -ENODEV;
- }
+ if (!idev || idev->dead)
+ goto out;

spin_lock_bh(&idev->mc_query_lock);
if (skb_queue_len(&idev->mc_query_queue) < MLD_MAX_SKBS) {
__skb_queue_tail(&idev->mc_query_queue, skb);
if (!mod_delayed_work(mld_wq, &idev->mc_query_work, 0))
in6_dev_hold(idev);
+ skb = NULL;
}
spin_unlock_bh(&idev->mc_query_lock);
-
- return 0;
+out:
+ kfree_skb(skb);
}

static void __mld_query_work(struct sk_buff *skb)
@@ -1542,27 +1538,23 @@ static void mld_query_work(struct work_struct *work)
}

/* called with rcu_read_lock() */
-int igmp6_event_report(struct sk_buff *skb)
+void igmp6_event_report(struct sk_buff *skb)
{
struct inet6_dev *idev = __in6_dev_get(skb->dev);

- if (!idev)
- return -EINVAL;
-
- if (idev->dead) {
- kfree_skb(skb);
- return -ENODEV;
- }
+ if (!idev || idev->dead)
+ goto out;

spin_lock_bh(&idev->mc_report_lock);
if (skb_queue_len(&idev->mc_report_queue) < MLD_MAX_SKBS) {
__skb_queue_tail(&idev->mc_report_queue, skb);
if (!mod_delayed_work(mld_wq, &idev->mc_report_work, 0))
in6_dev_hold(idev);
+ skb = NULL;
}
spin_unlock_bh(&idev->mc_report_lock);
-
- return 0;
+out:
+ kfree_skb(skb);
}

static void __mld_report_work(struct sk_buff *skb)
--
2.34.1


\
 
 \ /
  Last update: 2022-03-07 11:23    [W:0.444 / U:1.348 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site