summaryrefslogtreecommitdiff
path: root/net/packet
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2023-05-26 18:43:42 +0300
committerJakub Kicinski <kuba@kernel.org>2023-05-30 08:03:48 +0300
commit6ffc57ea004234d9373c57b204fd10370a69f392 (patch)
tree3ee21a4fe73ad89df54c48a290bf1c1699ec7201 /net/packet
parent0684f29a89e58944a9bfae3a8b5c1a217e44c960 (diff)
downloadlinux-6ffc57ea004234d9373c57b204fd10370a69f392.tar.xz
af_packet: do not use READ_ONCE() in packet_bind()
A recent patch added READ_ONCE() in packet_bind() and packet_bind_spkt() This is better handled by reading pkt_sk(sk)->num later in packet_do_bind() while appropriate lock is held. READ_ONCE() in writers are often an evidence of something being wrong. Fixes: 822b5a1c17df ("af_packet: Fix data-races of pkt_sk(sk)->num.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230526154342.2533026-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/packet')
-rw-r--r--net/packet/af_packet.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a1f9a0e9f3c8..a2dbeb264f26 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3201,6 +3201,9 @@ static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
lock_sock(sk);
spin_lock(&po->bind_lock);
+ if (!proto)
+ proto = po->num;
+
rcu_read_lock();
if (po->fanout) {
@@ -3299,7 +3302,7 @@ static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min));
name[sizeof(uaddr->sa_data_min)] = 0;
- return packet_do_bind(sk, name, 0, READ_ONCE(pkt_sk(sk)->num));
+ return packet_do_bind(sk, name, 0, 0);
}
static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
@@ -3316,8 +3319,7 @@ static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len
if (sll->sll_family != AF_PACKET)
return -EINVAL;
- return packet_do_bind(sk, NULL, sll->sll_ifindex,
- sll->sll_protocol ? : READ_ONCE(pkt_sk(sk)->num));
+ return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol);
}
static struct proto packet_proto = {