This is a note to let you know that I've just added the patch titled
ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()
to the 5.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipv6-fix-skb-drops-in-igmp6_event_query-and-igmp6_ev.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d524916e6a467112345767ffd5187488dfd6277c
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Thu Mar 3 09:37:28 2022 -0800
ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()
[ 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@xxxxxxxxxx>
Cc: Taehee Yoo <ap420073@xxxxxxxxx>
Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220303173728.937869-1-eric.dumazet@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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)
