Patch "xfrm: interface: use DEV_STATS_INC()" has been added to the 5.15-stable tree

[gre...@linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

xfrm: interface: use DEV_STATS_INC()

to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
xfrm-interface-use-dev_stats_inc.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <sta...@vger.kernel.org> know about it.


From f7c4e3e5d4f6609b4725a97451948ca2e425379a Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edum...@google.com>
Date: Tue, 5 Sep 2023 13:23:03 +0000
Subject: xfrm: interface: use DEV_STATS_INC()

From: Eric Dumazet <edum...@google.com>

commit f7c4e3e5d4f6609b4725a97451948ca2e425379a upstream.

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 <syzk...@googlegroups.com>
Signed-off-by: Eric Dumazet <edum...@google.com>
Cc: Steffen Klassert <steffen....@secunet.com>
Signed-off-by: Steffen Klassert <steffen....@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
net/xfrm/xfrm_interface_core.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)

--- a/net/xfrm/xfrm_interface_core.c
+++ b/net/xfrm/xfrm_interface_core.c
@@ -274,8 +274,8 @@ static int xfrmi_rcv_cb(struct sk_buff *
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;
}
@@ -309,7 +309,6 @@ 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;
@@ -335,7 +334,7 @@ xfrmi_xmit2(struct sk_buff *skb, struct
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;
@@ -374,13 +373,13 @@ xmit:
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);
@@ -390,7 +389,6 @@ tx_err_dst_release:
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;
@@ -407,7 +405,7 @@ static netdev_tx_t xfrmi_xmit(struct sk_
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);
@@ -423,7 +421,7 @@ static netdev_tx_t xfrmi_xmit(struct sk_
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);
@@ -442,8 +440,8 @@ static netdev_tx_t xfrmi_xmit(struct sk_
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;
}


Patches currently in stable-queue which might be from edum...@google.com are

queue-5.15/xfrm-fix-a-data-race-in-xfrm_gen_index.patch
queue-5.15/ipv4-fib-annotate-races-around-nh-nh_saddr_genid-and-nh-nh_saddr.patch
queue-5.15/tcp-fix-excessive-tlp-and-rack-timeouts-from-hz-rounding.patch
queue-5.15/tcp-tsq-relax-tcp_small_queue_check-when-rtx-queue-contains-a-single-skb.patch
queue-5.15/xfrm-interface-use-dev_stats_inc.patch
queue-5.15/tun-prevent-negative-ifindex.patch