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| author | Eric Dumazet <edumazet@google.com> | 2023-05-26 15:43:42 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-06-09 10:23:55 +0200 |
| commit | 4a94996e1d730f40b78e5b3fcbc62a83e1390f23 (patch) | |
| tree | 926d20ddc363eea5e663826155ac65593b366625 | |
| parent | 89f411ec10f2ef46908ad0257fbf89a32f3daf78 (diff) | |
| download | linux-stable-4a94996e1d730f40b78e5b3fcbc62a83e1390f23.tar.gz linux-stable-4a94996e1d730f40b78e5b3fcbc62a83e1390f23.tar.bz2 linux-stable-4a94996e1d730f40b78e5b3fcbc62a83e1390f23.zip | |
af_packet: do not use READ_ONCE() in packet_bind()
[ Upstream commit 6ffc57ea004234d9373c57b204fd10370a69f392 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 7409e042305d..fb165286e76d 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3117,6 +3117,9 @@ 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) { @@ -3219,7 +3222,7 @@ static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data)); name[sizeof(uaddr->sa_data)] = 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) @@ -3236,8 +3239,7 @@ 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 = { |