diff options
| author | Eric Dumazet | 2023-05-26 15:43:42 +0000 |
|---|---|---|
| committer | Jakub Kicinski | 2023-05-29 22:03:48 -0700 |
| commit | 6ffc57ea004234d9373c57b204fd10370a69f392 (patch) | |
| tree | 3ee21a4fe73ad89df54c48a290bf1c1699ec7201 /net/packet | |
| parent | 0684f29a89e58944a9bfae3a8b5c1a217e44c960 (diff) | |
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.c | 8 |
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 = { |