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author | Reshetova, Elena <elena.reshetova@intel.com> | 2017-06-30 13:08:01 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-07-01 07:39:08 -0700 |
commit | 41c6d650f6537e55a1b53438c646fbc3f49176bf (patch) | |
tree | d7fb3d5a2f1b3fb0fe76fa010141be563488d36b /net/ipv4/udp.c | |
parent | 14afee4b6092fde451ee17604e5f5c89da33e71e (diff) | |
download | lwn-41c6d650f6537e55a1b53438c646fbc3f49176bf.tar.gz lwn-41c6d650f6537e55a1b53438c646fbc3f49176bf.zip |
net: convert sock.sk_refcnt from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
-rw-r--r-- | net/ipv4/udp.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 86fad2a14ac4..25294d43e147 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -577,7 +577,7 @@ struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table, NULL); - if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) + if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) sk = NULL; return sk; } @@ -2242,7 +2242,7 @@ void udp_v4_early_demux(struct sk_buff *skb) uh->source, iph->saddr, dif); } - if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2)) + if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) return; skb->sk = sk; @@ -2691,7 +2691,7 @@ static void udp4_format_sock(struct sock *sp, struct seq_file *f, 0, 0L, 0, from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 0, sock_i_ino(sp), - atomic_read(&sp->sk_refcnt), sp, + refcount_read(&sp->sk_refcnt), sp, atomic_read(&sp->sk_drops)); } |