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| author | Eric Dumazet <edumazet@google.com> | 2019-06-06 14:32:34 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-22 08:16:14 +0200 |
| commit | 3cc4e63c97081b1017a589adc3c814da23dbc69b (patch) | |
| tree | 0b551ca68c75cf44e8a551938b7af5981e6a8e89 | |
| parent | 697ded8d3452bdfdff1e245a6aa62328918879a0 (diff) | |
| download | linux-stable-3cc4e63c97081b1017a589adc3c814da23dbc69b.tar.gz linux-stable-3cc4e63c97081b1017a589adc3c814da23dbc69b.tar.bz2 linux-stable-3cc4e63c97081b1017a589adc3c814da23dbc69b.zip | |
ipv6: flowlabel: fl6_sock_lookup() must use atomic_inc_not_zero
[ Upstream commit 65a3c497c0e965a552008db8bc2653f62bc925a1 ]
Before taking a refcount, make sure the object is not already
scheduled for deletion.
Same fix is needed in ipv6_flowlabel_opt()
Fixes: 18367681a10b ("ipv6 flowlabel: Convert np->ipv6_fl_list to RCU.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv6/ip6_flowlabel.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c index 6fa2bc236d9e..c7458a606e2e 100644 --- a/net/ipv6/ip6_flowlabel.c +++ b/net/ipv6/ip6_flowlabel.c @@ -254,9 +254,9 @@ struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label) rcu_read_lock_bh(); for_each_sk_fl_rcu(np, sfl) { struct ip6_flowlabel *fl = sfl->fl; - if (fl->label == label) { + + if (fl->label == label && atomic_inc_not_zero(&fl->users)) { fl->lastuse = jiffies; - atomic_inc(&fl->users); rcu_read_unlock_bh(); return fl; } @@ -623,7 +623,8 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen) goto done; } fl1 = sfl->fl; - atomic_inc(&fl1->users); + if (!atomic_inc_not_zero(&fl1->users)) + fl1 = NULL; break; } } |