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| author | Eric Dumazet <edumazet@google.com> | 2019-12-14 03:20:41 +0100 |
|---|---|---|
| committer | Jakub Kicinski <jakub.kicinski@netronome.com> | 2019-12-14 06:40:49 +0100 |
| commit | 8dbd76e79a16b45b2ccb01d2f2e08dbf64e71e40 (patch) | |
| tree | d904a539aa6360aa0e599d93f737f05752939ac0 /net/ipv4/inet_diag.c | |
| parent | net/ibmvnic: Fix typo in retry check (diff) | |
| download | linux-8dbd76e79a16b45b2ccb01d2f2e08dbf64e71e40.tar.xz linux-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 'net/ipv4/inet_diag.c')
| -rw-r--r-- | net/ipv4/inet_diag.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index af154977904c..f11e997e517b 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -911,11 +911,12 @@ void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb, for (i = s_i; i < INET_LHTABLE_SIZE; i++) { struct inet_listen_hashbucket *ilb; + struct hlist_nulls_node *node; num = 0; ilb = &hashinfo->listening_hash[i]; spin_lock(&ilb->lock); - sk_for_each(sk, &ilb->head) { + sk_nulls_for_each(sk, node, &ilb->nulls_head) { struct inet_sock *inet = inet_sk(sk); if (!net_eq(sock_net(sk), net)) |