From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
Kuniyuki Iwashima <kuniyu@google.com>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>,
Sabrina Dubroca <sd@queasysnail.net>,
Andrew Lunn <andrew+netdev@lunn.ch>
Subject: [PATCH net-next] macsec: no longer rely on RTNL in macsec_fill_info()
Date: Wed, 1 Jul 2026 09:43:41 +0000 [thread overview]
Message-ID: <20260701094341.3218199-1-edumazet@google.com> (raw)
Add READ_ONCE()/WRITE_ONCE() annotations on fields that can be
changed concurrently in macsec_changelink() and macsec_update_offload():
- secy->key_len
- secy->xpn
- tx_sc->encoding_sa
- tx_sc->encrypt
- secy->protect_frames
- tx_sc->send_sci
- tx_sc->end_station
- tx_sc->scb
- secy->replay_protect
- secy->validate_frames
- secy->replay_window
- macsec->offload
This allows macsec_fill_info() to run locklessly without RTNL.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
---
drivers/net/macsec.c | 78 +++++++++++++++++++++++---------------------
1 file changed, 40 insertions(+), 38 deletions(-)
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index fb009120a92415cf51f12eab15b4c7925a25704d..1a968596ca45b8deb028b86207a501dbf3116f0f 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -2636,7 +2636,7 @@ static int macsec_update_offload(struct net_device *dev,
vlan_drop_rx_ctag_filter_info(dev);
vlan_drop_rx_stag_filter_info(dev);
}
- macsec->offload = offload;
+ WRITE_ONCE(macsec->offload, offload);
/* Add VLAN filters when enabling offload. */
if (prev_offload == MACSEC_OFFLOAD_OFF) {
ret = vlan_get_rx_ctag_filter_info(dev);
@@ -2666,7 +2666,7 @@ static int macsec_update_offload(struct net_device *dev,
return 0;
rollback_offload:
- macsec->offload = prev_offload;
+ WRITE_ONCE(macsec->offload, prev_offload);
macsec_offload(ops->mdo_del_secy, &ctx);
return ret;
@@ -3875,52 +3875,53 @@ static int macsec_changelink_common(struct net_device *dev,
if (data[IFLA_MACSEC_ENCODING_SA]) {
struct macsec_tx_sa *tx_sa;
+ u8 encoding_sa = nla_get_u8(data[IFLA_MACSEC_ENCODING_SA]);
- tx_sc->encoding_sa = nla_get_u8(data[IFLA_MACSEC_ENCODING_SA]);
- tx_sa = rtnl_dereference(tx_sc->sa[tx_sc->encoding_sa]);
+ WRITE_ONCE(tx_sc->encoding_sa, encoding_sa);
+ tx_sa = rtnl_dereference(tx_sc->sa[encoding_sa]);
secy->operational = tx_sa && tx_sa->active;
}
if (data[IFLA_MACSEC_ENCRYPT])
- tx_sc->encrypt = !!nla_get_u8(data[IFLA_MACSEC_ENCRYPT]);
+ WRITE_ONCE(tx_sc->encrypt, !!nla_get_u8(data[IFLA_MACSEC_ENCRYPT]));
if (data[IFLA_MACSEC_PROTECT])
- secy->protect_frames = !!nla_get_u8(data[IFLA_MACSEC_PROTECT]);
+ WRITE_ONCE(secy->protect_frames, !!nla_get_u8(data[IFLA_MACSEC_PROTECT]));
if (data[IFLA_MACSEC_INC_SCI])
- tx_sc->send_sci = !!nla_get_u8(data[IFLA_MACSEC_INC_SCI]);
+ WRITE_ONCE(tx_sc->send_sci, !!nla_get_u8(data[IFLA_MACSEC_INC_SCI]));
if (data[IFLA_MACSEC_ES])
- tx_sc->end_station = !!nla_get_u8(data[IFLA_MACSEC_ES]);
+ WRITE_ONCE(tx_sc->end_station, !!nla_get_u8(data[IFLA_MACSEC_ES]));
if (data[IFLA_MACSEC_SCB])
- tx_sc->scb = !!nla_get_u8(data[IFLA_MACSEC_SCB]);
+ WRITE_ONCE(tx_sc->scb, !!nla_get_u8(data[IFLA_MACSEC_SCB]));
if (data[IFLA_MACSEC_REPLAY_PROTECT])
- secy->replay_protect = !!nla_get_u8(data[IFLA_MACSEC_REPLAY_PROTECT]);
+ WRITE_ONCE(secy->replay_protect, !!nla_get_u8(data[IFLA_MACSEC_REPLAY_PROTECT]));
if (data[IFLA_MACSEC_VALIDATION])
- secy->validate_frames = nla_get_u8(data[IFLA_MACSEC_VALIDATION]);
+ WRITE_ONCE(secy->validate_frames, nla_get_u8(data[IFLA_MACSEC_VALIDATION]));
if (data[IFLA_MACSEC_CIPHER_SUITE]) {
switch (nla_get_u64(data[IFLA_MACSEC_CIPHER_SUITE])) {
case MACSEC_CIPHER_ID_GCM_AES_128:
case MACSEC_DEFAULT_CIPHER_ID:
- secy->key_len = MACSEC_GCM_AES_128_SAK_LEN;
- secy->xpn = false;
+ WRITE_ONCE(secy->key_len, MACSEC_GCM_AES_128_SAK_LEN);
+ WRITE_ONCE(secy->xpn, false);
break;
case MACSEC_CIPHER_ID_GCM_AES_256:
- secy->key_len = MACSEC_GCM_AES_256_SAK_LEN;
- secy->xpn = false;
+ WRITE_ONCE(secy->key_len, MACSEC_GCM_AES_256_SAK_LEN);
+ WRITE_ONCE(secy->xpn, false);
break;
case MACSEC_CIPHER_ID_GCM_AES_XPN_128:
- secy->key_len = MACSEC_GCM_AES_128_SAK_LEN;
- secy->xpn = true;
+ WRITE_ONCE(secy->key_len, MACSEC_GCM_AES_128_SAK_LEN);
+ WRITE_ONCE(secy->xpn, true);
break;
case MACSEC_CIPHER_ID_GCM_AES_XPN_256:
- secy->key_len = MACSEC_GCM_AES_256_SAK_LEN;
- secy->xpn = true;
+ WRITE_ONCE(secy->key_len, MACSEC_GCM_AES_256_SAK_LEN);
+ WRITE_ONCE(secy->xpn, true);
break;
default:
return -EINVAL;
@@ -3928,13 +3929,14 @@ static int macsec_changelink_common(struct net_device *dev,
}
if (data[IFLA_MACSEC_WINDOW]) {
- secy->replay_window = nla_get_u32(data[IFLA_MACSEC_WINDOW]);
+ u32 replay_window = nla_get_u32(data[IFLA_MACSEC_WINDOW]);
/* IEEE 802.1AEbw-2013 10.7.8 - maximum replay window
* for XPN cipher suites */
if (secy->xpn &&
- secy->replay_window > MACSEC_XPN_MAX_REPLAY_WINDOW)
+ replay_window > MACSEC_XPN_MAX_REPLAY_WINDOW)
return -EINVAL;
+ WRITE_ONCE(secy->replay_window, replay_window);
}
return 0;
@@ -4382,21 +4384,21 @@ static size_t macsec_get_size(const struct net_device *dev)
static int macsec_fill_info(struct sk_buff *skb,
const struct net_device *dev)
{
- struct macsec_tx_sc *tx_sc;
- struct macsec_dev *macsec;
- struct macsec_secy *secy;
+ const struct macsec_tx_sc *tx_sc;
+ const struct macsec_dev *macsec;
+ const struct macsec_secy *secy;
u64 csid;
macsec = macsec_priv(dev);
secy = &macsec->secy;
tx_sc = &secy->tx_sc;
- switch (secy->key_len) {
+ switch (READ_ONCE(secy->key_len)) {
case MACSEC_GCM_AES_128_SAK_LEN:
- csid = secy->xpn ? MACSEC_CIPHER_ID_GCM_AES_XPN_128 : MACSEC_DEFAULT_CIPHER_ID;
+ csid = READ_ONCE(secy->xpn) ? MACSEC_CIPHER_ID_GCM_AES_XPN_128 : MACSEC_DEFAULT_CIPHER_ID;
break;
case MACSEC_GCM_AES_256_SAK_LEN:
- csid = secy->xpn ? MACSEC_CIPHER_ID_GCM_AES_XPN_256 : MACSEC_CIPHER_ID_GCM_AES_256;
+ csid = READ_ONCE(secy->xpn) ? MACSEC_CIPHER_ID_GCM_AES_XPN_256 : MACSEC_CIPHER_ID_GCM_AES_256;
break;
default:
goto nla_put_failure;
@@ -4407,20 +4409,20 @@ static int macsec_fill_info(struct sk_buff *skb,
nla_put_u8(skb, IFLA_MACSEC_ICV_LEN, secy->icv_len) ||
nla_put_u64_64bit(skb, IFLA_MACSEC_CIPHER_SUITE,
csid, IFLA_MACSEC_PAD) ||
- nla_put_u8(skb, IFLA_MACSEC_ENCODING_SA, tx_sc->encoding_sa) ||
- nla_put_u8(skb, IFLA_MACSEC_ENCRYPT, tx_sc->encrypt) ||
- nla_put_u8(skb, IFLA_MACSEC_PROTECT, secy->protect_frames) ||
- nla_put_u8(skb, IFLA_MACSEC_INC_SCI, tx_sc->send_sci) ||
- nla_put_u8(skb, IFLA_MACSEC_ES, tx_sc->end_station) ||
- nla_put_u8(skb, IFLA_MACSEC_SCB, tx_sc->scb) ||
- nla_put_u8(skb, IFLA_MACSEC_REPLAY_PROTECT, secy->replay_protect) ||
- nla_put_u8(skb, IFLA_MACSEC_VALIDATION, secy->validate_frames) ||
- nla_put_u8(skb, IFLA_MACSEC_OFFLOAD, macsec->offload) ||
+ nla_put_u8(skb, IFLA_MACSEC_ENCODING_SA, READ_ONCE(tx_sc->encoding_sa)) ||
+ nla_put_u8(skb, IFLA_MACSEC_ENCRYPT, READ_ONCE(tx_sc->encrypt)) ||
+ nla_put_u8(skb, IFLA_MACSEC_PROTECT, READ_ONCE(secy->protect_frames)) ||
+ nla_put_u8(skb, IFLA_MACSEC_INC_SCI, READ_ONCE(tx_sc->send_sci)) ||
+ nla_put_u8(skb, IFLA_MACSEC_ES, READ_ONCE(tx_sc->end_station)) ||
+ nla_put_u8(skb, IFLA_MACSEC_SCB, READ_ONCE(tx_sc->scb)) ||
+ nla_put_u8(skb, IFLA_MACSEC_REPLAY_PROTECT, READ_ONCE(secy->replay_protect)) ||
+ nla_put_u8(skb, IFLA_MACSEC_VALIDATION, READ_ONCE(secy->validate_frames)) ||
+ nla_put_u8(skb, IFLA_MACSEC_OFFLOAD, READ_ONCE(macsec->offload)) ||
0)
goto nla_put_failure;
- if (secy->replay_protect) {
- if (nla_put_u32(skb, IFLA_MACSEC_WINDOW, secy->replay_window))
+ if (READ_ONCE(secy->replay_protect)) {
+ if (nla_put_u32(skb, IFLA_MACSEC_WINDOW, READ_ONCE(secy->replay_window)))
goto nla_put_failure;
}
--
2.55.0.rc0.799.gd6f94ed593-goog
next reply other threads:[~2026-07-01 9:43 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-01 9:43 Eric Dumazet [this message]
2026-07-01 22:27 ` [PATCH net-next] macsec: no longer rely on RTNL in macsec_fill_info() Kuniyuki Iwashima
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