| From f41062b5a4253e1453928bee2390321bfb4033bd Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 5 Jul 2021 15:38:10 +0000 |
| Subject: bonding: fix suspicious RCU usage in bond_ipsec_del_sa() |
| |
| From: Taehee Yoo <ap420073@gmail.com> |
| |
| [ Upstream commit a22c39b831a081da9b2c488bd970a4412d926f30 ] |
| |
| To dereference bond->curr_active_slave, it uses rcu_dereference(). |
| But it and the caller doesn't acquire RCU so a warning occurs. |
| So add rcu_read_lock(). |
| |
| Test commands: |
| ip netns add A |
| ip netns exec A bash |
| modprobe netdevsim |
| echo "1 1" > /sys/bus/netdevsim/new_device |
| ip link add bond0 type bond |
| ip link set eth0 master bond0 |
| ip link set eth0 up |
| ip link set bond0 up |
| ip x s add proto esp dst 14.1.1.1 src 15.1.1.1 spi 0x07 mode \ |
| transport reqid 0x07 replay-window 32 aead 'rfc4106(gcm(aes))' \ |
| 0x44434241343332312423222114131211f4f3f2f1 128 sel src 14.0.0.52/24 \ |
| dst 14.0.0.70/24 proto tcp offload dev bond0 dir in |
| ip x s f |
| |
| Splat looks like: |
| ============================= |
| WARNING: suspicious RCU usage |
| 5.13.0-rc3+ #1168 Not tainted |
| ----------------------------- |
| drivers/net/bonding/bond_main.c:448 suspicious rcu_dereference_check() |
| usage! |
| |
| other info that might help us debug this: |
| |
| rcu_scheduler_active = 2, debug_locks = 1 |
| 2 locks held by ip/705: |
| #0: ffff888106701780 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{3:3}, |
| at: xfrm_netlink_rcv+0x59/0x80 [xfrm_user] |
| #1: ffff8880075b0098 (&x->lock){+.-.}-{2:2}, |
| at: xfrm_state_delete+0x16/0x30 |
| |
| stack backtrace: |
| CPU: 6 PID: 705 Comm: ip Not tainted 5.13.0-rc3+ #1168 |
| Call Trace: |
| dump_stack+0xa4/0xe5 |
| bond_ipsec_del_sa+0x16a/0x1c0 [bonding] |
| __xfrm_state_delete+0x51f/0x730 |
| xfrm_state_delete+0x1e/0x30 |
| xfrm_state_flush+0x22f/0x390 |
| xfrm_flush_sa+0xd8/0x260 [xfrm_user] |
| ? xfrm_flush_policy+0x290/0x290 [xfrm_user] |
| xfrm_user_rcv_msg+0x331/0x660 [xfrm_user] |
| ? rcu_read_lock_sched_held+0x91/0xc0 |
| ? xfrm_user_state_lookup.constprop.39+0x320/0x320 [xfrm_user] |
| ? find_held_lock+0x3a/0x1c0 |
| ? mutex_lock_io_nested+0x1210/0x1210 |
| ? sched_clock_cpu+0x18/0x170 |
| netlink_rcv_skb+0x121/0x350 |
| [ ... ] |
| |
| Fixes: 18cb261afd7b ("bonding: support hardware encryption offload to slaves") |
| Signed-off-by: Taehee Yoo <ap420073@gmail.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/bonding/bond_main.c | 7 +++++-- |
| 1 file changed, 5 insertions(+), 2 deletions(-) |
| |
| diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c |
| index 24b33118105a..a7b6550063b2 100644 |
| --- a/drivers/net/bonding/bond_main.c |
| +++ b/drivers/net/bonding/bond_main.c |
| @@ -444,21 +444,24 @@ static void bond_ipsec_del_sa(struct xfrm_state *xs) |
| if (!bond_dev) |
| return; |
| |
| + rcu_read_lock(); |
| bond = netdev_priv(bond_dev); |
| slave = rcu_dereference(bond->curr_active_slave); |
| |
| if (!slave) |
| - return; |
| + goto out; |
| |
| xs->xso.real_dev = slave->dev; |
| |
| if (!(slave->dev->xfrmdev_ops |
| && slave->dev->xfrmdev_ops->xdo_dev_state_delete)) { |
| slave_warn(bond_dev, slave->dev, "%s: no slave xdo_dev_state_delete\n", __func__); |
| - return; |
| + goto out; |
| } |
| |
| slave->dev->xfrmdev_ops->xdo_dev_state_delete(xs); |
| +out: |
| + rcu_read_unlock(); |
| } |
| |
| /** |
| -- |
| 2.30.2 |
| |