diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-03-16 01:10:06 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-11 23:03:18 +0900 |
| commit | f2d971608a88976612ed5c26af352d31305cd294 (patch) | |
| tree | fd64ae085af9473a587f45a14095b0d7f270b09e /net | |
| parent | c3ee3540a133039507da934af0673cf5445a0972 (diff) | |
| download | linux-stable-f2d971608a88976612ed5c26af352d31305cd294.tar.gz linux-stable-f2d971608a88976612ed5c26af352d31305cd294.tar.bz2 linux-stable-f2d971608a88976612ed5c26af352d31305cd294.zip | |
net/packet: annotate accesses to po->xmit
[ Upstream commit b9d83ab8a708f23a4001d60e9d8d0b3be3d9f607 ]
po->xmit can be set from setsockopt(PACKET_QDISC_BYPASS),
while read locklessly.
Use READ_ONCE()/WRITE_ONCE() to avoid potential load/store
tearing issues.
Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/packet/af_packet.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 1ab65f7f2a0a..b5487bd8ffc9 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -307,7 +307,8 @@ static void packet_cached_dev_reset(struct packet_sock *po) static bool packet_use_direct_xmit(const struct packet_sock *po) { - return po->xmit == packet_direct_xmit; + /* Paired with WRITE_ONCE() in packet_setsockopt() */ + return READ_ONCE(po->xmit) == packet_direct_xmit; } static u16 packet_pick_tx_queue(struct sk_buff *skb) @@ -2866,7 +2867,8 @@ tpacket_error: packet_inc_pending(&po->tx_ring); status = TP_STATUS_SEND_REQUEST; - err = po->xmit(skb); + /* Paired with WRITE_ONCE() in packet_setsockopt() */ + err = READ_ONCE(po->xmit)(skb); if (unlikely(err != 0)) { if (err > 0) err = net_xmit_errno(err); @@ -3069,7 +3071,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) virtio_net_hdr_set_proto(skb, &vnet_hdr); } - err = po->xmit(skb); + /* Paired with WRITE_ONCE() in packet_setsockopt() */ + err = READ_ONCE(po->xmit)(skb); if (unlikely(err != 0)) { if (err > 0) err = net_xmit_errno(err); @@ -4006,7 +4009,8 @@ packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, if (copy_from_sockptr(&val, optval, sizeof(val))) return -EFAULT; - po->xmit = val ? packet_direct_xmit : dev_queue_xmit; + /* Paired with all lockless reads of po->xmit */ + WRITE_ONCE(po->xmit, val ? packet_direct_xmit : dev_queue_xmit); return 0; } default: |