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| author | Eric Dumazet <edumazet@google.com> | 2019-06-06 14:32:34 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-06-09 13:07:14 -0700 |
| commit | 65a3c497c0e965a552008db8bc2653f62bc925a1 (patch) | |
| tree | b3123d60841736cf01855d36332b3f0410a3129b /net/ipv6/ip6_flowlabel.c | |
| parent | c3fee640bcf52c34a25b767f2b0eda82e97a1f3b (diff) | |
| download | linux-65a3c497c0e965a552008db8bc2653f62bc925a1.tar.gz | |
ipv6: flowlabel: fl6_sock_lookup() must use atomic_inc_not_zero
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>
Diffstat (limited to 'net/ipv6/ip6_flowlabel.c')
| -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 2f3eb7dc45daa..545e339b8c4fb 100644 --- a/net/ipv6/ip6_flowlabel.c +++ b/net/ipv6/ip6_flowlabel.c @@ -250,9 +250,9 @@ 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; } @@ -618,7 +618,8 @@ 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; } } |