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 a66d639c415f..952796fb5f1a 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -428,21 +428,24 @@ 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(); }
/**