[Devel] [PATCH vz9 1/6] ms/xfrm: interface: use DEV_STATS_INC()

Konstantin Khorenko khorenko at virtuozzo.com
Tue Mar 11 19:33:39 MSK 2025


From: Sabrina Dubroca <sdubroca at redhat.com>

JIRA: https://issues.redhat.com/browse/RHEL-31751

commit f7c4e3e5d4f6609b4725a97451948ca2e425379a
Author: Eric Dumazet <edumazet at google.com>
Date:   Tue Sep 5 13:23:03 2023 +0000

    xfrm: interface: use DEV_STATS_INC()

    syzbot/KCSAN reported data-races in xfrm whenever dev->stats fields
    are updated.

    It appears all of these updates can happen from multiple cpus.

    Adopt SMP safe DEV_STATS_INC() to update dev->stats fields.

    BUG: KCSAN: data-race in xfrmi_xmit / xfrmi_xmit

    read-write to 0xffff88813726b160 of 8 bytes by task 23986 on cpu 1:
    xfrmi_xmit+0x74e/0xb20 net/xfrm/xfrm_interface_core.c:583
    __netdev_start_xmit include/linux/netdevice.h:4889 [inline]
    netdev_start_xmit include/linux/netdevice.h:4903 [inline]
    xmit_one net/core/dev.c:3544 [inline]
    dev_hard_start_xmit+0x11b/0x3f0 net/core/dev.c:3560
    __dev_queue_xmit+0xeee/0x1de0 net/core/dev.c:4340
    dev_queue_xmit include/linux/netdevice.h:3082 [inline]
    neigh_connected_output+0x231/0x2a0 net/core/neighbour.c:1581
    neigh_output include/net/neighbour.h:542 [inline]
    ip_finish_output2+0x74a/0x850 net/ipv4/ip_output.c:230
    ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:318
    NF_HOOK_COND include/linux/netfilter.h:293 [inline]
    ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:432
    dst_output include/net/dst.h:458 [inline]
    ip_local_out net/ipv4/ip_output.c:127 [inline]
    ip_send_skb+0x72/0xe0 net/ipv4/ip_output.c:1487
    udp_send_skb+0x6a4/0x990 net/ipv4/udp.c:963
    udp_sendmsg+0x1249/0x12d0 net/ipv4/udp.c:1246
    inet_sendmsg+0x63/0x80 net/ipv4/af_inet.c:840
    sock_sendmsg_nosec net/socket.c:730 [inline]
    sock_sendmsg net/socket.c:753 [inline]
    ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2540
    ___sys_sendmsg net/socket.c:2594 [inline]
    __sys_sendmmsg+0x269/0x500 net/socket.c:2680
    __do_sys_sendmmsg net/socket.c:2709 [inline]
    __se_sys_sendmmsg net/socket.c:2706 [inline]
    __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2706
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

    read-write to 0xffff88813726b160 of 8 bytes by task 23987 on cpu 0:
    xfrmi_xmit+0x74e/0xb20 net/xfrm/xfrm_interface_core.c:583
    __netdev_start_xmit include/linux/netdevice.h:4889 [inline]
    netdev_start_xmit include/linux/netdevice.h:4903 [inline]
    xmit_one net/core/dev.c:3544 [inline]
    dev_hard_start_xmit+0x11b/0x3f0 net/core/dev.c:3560
    __dev_queue_xmit+0xeee/0x1de0 net/core/dev.c:4340
    dev_queue_xmit include/linux/netdevice.h:3082 [inline]
    neigh_connected_output+0x231/0x2a0 net/core/neighbour.c:1581
    neigh_output include/net/neighbour.h:542 [inline]
    ip_finish_output2+0x74a/0x850 net/ipv4/ip_output.c:230
    ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:318
    NF_HOOK_COND include/linux/netfilter.h:293 [inline]
    ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:432
    dst_output include/net/dst.h:458 [inline]
    ip_local_out net/ipv4/ip_output.c:127 [inline]
    ip_send_skb+0x72/0xe0 net/ipv4/ip_output.c:1487
    udp_send_skb+0x6a4/0x990 net/ipv4/udp.c:963
    udp_sendmsg+0x1249/0x12d0 net/ipv4/udp.c:1246
    inet_sendmsg+0x63/0x80 net/ipv4/af_inet.c:840
    sock_sendmsg_nosec net/socket.c:730 [inline]
    sock_sendmsg net/socket.c:753 [inline]
    ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2540
    ___sys_sendmsg net/socket.c:2594 [inline]
    __sys_sendmmsg+0x269/0x500 net/socket.c:2680
    __do_sys_sendmmsg net/socket.c:2709 [inline]
    __se_sys_sendmmsg net/socket.c:2706 [inline]
    __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2706
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

    value changed: 0x00000000000010d7 -> 0x00000000000010d8

    Reported by Kernel Concurrency Sanitizer on:
    CPU: 0 PID: 23987 Comm: syz-executor.5 Not tainted 6.5.0-syzkaller-10885-g0468be89b3fa #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023

    Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
    Reported-by: syzbot <syzkaller at googlegroups.com>
    Signed-off-by: Eric Dumazet <edumazet at google.com>
    Cc: Steffen Klassert <steffen.klassert at secunet.com>
    Signed-off-by: Steffen Klassert <steffen.klassert at secunet.com>

Signed-off-by: Sabrina Dubroca <sdubroca at redhat.com>

https://virtuozzo.atlassian.net/browse/VSTOR-101702
(cherry picked from CentOS Stream commit 6b50b0bac39b13db9edce8899ee4de363dc95ef9)
Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>

Feature: fix ms/xfrm
---
 net/xfrm/xfrm_interface_core.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/net/xfrm/xfrm_interface_core.c b/net/xfrm/xfrm_interface_core.c
index 3baf81d9974c..47e502310c5e 100644
--- a/net/xfrm/xfrm_interface_core.c
+++ b/net/xfrm/xfrm_interface_core.c
@@ -334,8 +334,8 @@ static int xfrmi_rcv_cb(struct sk_buff *skb, int err)
 	skb->dev = dev;
 
 	if (err) {
-		dev->stats.rx_errors++;
-		dev->stats.rx_dropped++;
+		DEV_STATS_INC(dev, rx_errors);
+		DEV_STATS_INC(dev, rx_dropped);
 
 		return 0;
 	}
@@ -380,7 +380,6 @@ static int
 xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 {
 	struct xfrm_if *xi = netdev_priv(dev);
-	struct net_device_stats *stats = &xi->dev->stats;
 	struct dst_entry *dst = skb_dst(skb);
 	unsigned int length = skb->len;
 	struct net_device *tdev;
@@ -427,7 +426,7 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 	tdev = dst->dev;
 
 	if (tdev == dev) {
-		stats->collisions++;
+		DEV_STATS_INC(dev, collisions);
 		net_warn_ratelimited("%s: Local routing loop detected!\n",
 				     dev->name);
 		goto tx_err_dst_release;
@@ -466,13 +465,13 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 	if (net_xmit_eval(err) == 0) {
 		dev_sw_netstats_tx_add(dev, 1, length);
 	} else {
-		stats->tx_errors++;
-		stats->tx_aborted_errors++;
+		DEV_STATS_INC(dev, tx_errors);
+		DEV_STATS_INC(dev, tx_aborted_errors);
 	}
 
 	return 0;
 tx_err_link_failure:
-	stats->tx_carrier_errors++;
+	DEV_STATS_INC(dev, tx_carrier_errors);
 	dst_link_failure(skb);
 tx_err_dst_release:
 	dst_release(dst);
@@ -482,7 +481,6 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 static netdev_tx_t xfrmi_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct xfrm_if *xi = netdev_priv(dev);
-	struct net_device_stats *stats = &xi->dev->stats;
 	struct dst_entry *dst = skb_dst(skb);
 	struct flowi fl;
 	int ret;
@@ -499,7 +497,7 @@ static netdev_tx_t xfrmi_xmit(struct sk_buff *skb, struct net_device *dev)
 			dst = ip6_route_output(dev_net(dev), NULL, &fl.u.ip6);
 			if (dst->error) {
 				dst_release(dst);
-				stats->tx_carrier_errors++;
+				DEV_STATS_INC(dev, tx_carrier_errors);
 				goto tx_err;
 			}
 			skb_dst_set(skb, dst);
@@ -515,7 +513,7 @@ static netdev_tx_t xfrmi_xmit(struct sk_buff *skb, struct net_device *dev)
 			fl.u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
 			rt = __ip_route_output_key(dev_net(dev), &fl.u.ip4);
 			if (IS_ERR(rt)) {
-				stats->tx_carrier_errors++;
+				DEV_STATS_INC(dev, tx_carrier_errors);
 				goto tx_err;
 			}
 			skb_dst_set(skb, &rt->dst);
@@ -534,8 +532,8 @@ static netdev_tx_t xfrmi_xmit(struct sk_buff *skb, struct net_device *dev)
 	return NETDEV_TX_OK;
 
 tx_err:
-	stats->tx_errors++;
-	stats->tx_dropped++;
+	DEV_STATS_INC(dev, tx_errors);
+	DEV_STATS_INC(dev, tx_dropped);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }
-- 
2.43.0



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