| From 135a5999c3b5c8f350ee70a65c5fafe11930da2d Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 5 Jul 2021 15:38:06 +0000 |
| Subject: bonding: fix suspicious RCU usage in bond_ipsec_add_sa() |
| |
| From: Taehee Yoo <ap420073@gmail.com> |
| |
| [ Upstream commit b648eba4c69e5819880b4907e7fcb2bb576069ab ] |
| |
| 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 link add dummy0 type dummy |
| ip link add bond0 type bond |
| ip link set dummy0 master bond0 |
| ip link set dummy0 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 |
| |
| Splat looks like: |
| ============================= |
| WARNING: suspicious RCU usage |
| 5.13.0-rc3+ #1168 Not tainted |
| ----------------------------- |
| drivers/net/bonding/bond_main.c:411 suspicious rcu_dereference_check() usage! |
| |
| other info that might help us debug this: |
| |
| rcu_scheduler_active = 2, debug_locks = 1 |
| 1 lock held by ip/684: |
| #0: ffffffff9a2757c0 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{3:3}, |
| at: xfrm_netlink_rcv+0x59/0x80 [xfrm_user] |
| 55.191733][ T684] stack backtrace: |
| CPU: 0 PID: 684 Comm: ip Not tainted 5.13.0-rc3+ #1168 |
| Call Trace: |
| dump_stack+0xa4/0xe5 |
| bond_ipsec_add_sa+0x18c/0x1f0 [bonding] |
| xfrm_dev_state_add+0x2a9/0x770 |
| ? memcpy+0x38/0x60 |
| xfrm_add_sa+0x2278/0x3b10 [xfrm_user] |
| ? xfrm_get_policy+0xaa0/0xaa0 [xfrm_user] |
| ? register_lock_class+0x1750/0x1750 |
| 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 |
| ? xfrm_user_state_lookup.constprop.39+0x320/0x320 [xfrm_user] |
| ? netlink_ack+0x9d0/0x9d0 |
| ? netlink_deliver_tap+0x17c/0xa50 |
| xfrm_netlink_rcv+0x68/0x80 [xfrm_user] |
| netlink_unicast+0x41c/0x610 |
| ? netlink_attachskb+0x710/0x710 |
| netlink_sendmsg+0x6b9/0xb70 |
| [ ... ] |
| |
| 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, 6 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c |
| index c5a646d06102..026f4511bf7b 100644 |
| --- a/drivers/net/bonding/bond_main.c |
| +++ b/drivers/net/bonding/bond_main.c |
| @@ -403,10 +403,12 @@ static int bond_ipsec_add_sa(struct xfrm_state *xs) |
| struct net_device *bond_dev = xs->xso.dev; |
| struct bonding *bond; |
| struct slave *slave; |
| + int err; |
| |
| if (!bond_dev) |
| return -EINVAL; |
| |
| + rcu_read_lock(); |
| bond = netdev_priv(bond_dev); |
| slave = rcu_dereference(bond->curr_active_slave); |
| xs->xso.real_dev = slave->dev; |
| @@ -415,10 +417,13 @@ static int bond_ipsec_add_sa(struct xfrm_state *xs) |
| if (!(slave->dev->xfrmdev_ops |
| && slave->dev->xfrmdev_ops->xdo_dev_state_add)) { |
| slave_warn(bond_dev, slave->dev, "Slave does not support ipsec offload\n"); |
| + rcu_read_unlock(); |
| return -EINVAL; |
| } |
| |
| - return slave->dev->xfrmdev_ops->xdo_dev_state_add(xs); |
| + err = slave->dev->xfrmdev_ops->xdo_dev_state_add(xs); |
| + rcu_read_unlock(); |
| + return err; |
| } |
| |
| /** |
| -- |
| 2.30.2 |
| |