diff mbox series

[net] ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()

Message ID 20220303173728.937869-1-eric.dumazet@gmail.com (mailing list archive)
State Accepted
Commit 2d3916f3189172d5c69d33065c3c21119fe539fc
Delegated to: Netdev Maintainers
Headers show
Series [net] ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report() | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2091 this patch: 2091
netdev/cc_maintainers warning 1 maintainers not CCed: yoshfuji@linux-ipv6.org
netdev/build_clang success Errors and warnings before: 292 this patch: 292
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 2220 this patch: 2220
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 77 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet March 3, 2022, 5:37 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

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>
---
 include/net/ndisc.h |  4 ++--
 net/ipv6/mcast.c    | 32 ++++++++++++--------------------
 2 files changed, 14 insertions(+), 22 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org March 3, 2022, 6:50 p.m. UTC | #1 
Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Thu,  3 Mar 2022 09:37:28 -0800 you wrote:
> From: Eric Dumazet <edumazet@google.com>
> 
> 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.
> 
> [...]

Here is the summary with links:
  - [net] ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()
    https://git.kernel.org/netdev/net/c/2d3916f31891

You are awesome, thank you!
diff mbox series

Patch

diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index 53cb8de0e589cec4161051a3cfd27de138b282ff..47ffb360ddfac154372d5cf8729a113e5ef736a0 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 a8861db52c1877e8bb94a0eee9154af7340d1ba1..909f937befd71fce194517d44cb9a4c5e2876360 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)