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| author |   Eric Dumazet <edumazet@google.com> | 2019-12-13 18:20:41 -0800 |
|---|---|---|
| committer |   Jakub Kicinski <jakub.kicinski@netronome.com> | 2019-12-13 21:40:49 -0800 |
| commit | 8dbd76e79a16b45b2ccb01d2f2e08dbf64e71e40 (patch) | |
| tree | d904a539aa6360aa0e599d93f737f05752939ac0 /include/net/sock.h | |
| parent | net/ibmvnic: Fix typo in retry check (diff) | |
| download | linux-dev-8dbd76e79a16b45b2ccb01d2f2e08dbf64e71e40.tar.xz linux-dev-8dbd76e79a16b45b2ccb01d2f2e08dbf64e71e40.zip | |
tcp/dccp: fix possible race __inet_lookup_established()
Michal Kubecek and Firo Yang did a very nice analysis of crashes
happening in __inet_lookup_established().
Since a TCP socket can go from TCP_ESTABLISH to TCP_LISTEN
(via a close()/socket()/listen() cycle) without a RCU grace period,
I should not have changed listeners linkage in their hash table.
They must use the nulls protocol (Documentation/RCU/rculist_nulls.txt),
so that a lookup can detect a socket in a hash list was moved in
another one.
Since we added code in commit d296ba60d8e2 ("soreuseport: Resolve
merge conflict for v4/v6 ordering fix"), we have to add
hlist_nulls_add_tail_rcu() helper.
Fixes: 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Reported-by: Firo Yang <firo.yang@suse.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Link: https://lore.kernel.org/netdev/20191120083919.GH27852@unicorn.suse.cz/
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index 87d54ef57f00..04c274a20620 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -722,6 +722,11 @@ static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_h hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); } +static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list) +{ + hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list); +} + static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) { sock_hold(sk); |