From 2d3916f3189172d5c69d33065c3c21119fe539fc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 3 Mar 2022 09:37:28 -0800 Subject: [PATCH] ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report() 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 Cc: Taehee Yoo Cc: Cong Wang Cc: David Ahern Link: https://lore.kernel.org/r/20220303173728.937869-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski --- 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 53cb8de0e589..47ffb360ddfa 100644 --- a/include/net/ndisc.h +++ b/include/net/ndisc.h @@ -475,9 +475,9 @@ 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 a8861db52c18..909f937befd7 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) -- 2.11.0