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author | 2020-02-27 12:24:45 +0000 | |
---|---|---|
committer | 2020-02-27 11:45:07 -0800 | |
commit | 102210f7664442d8c0ce332c006ea90626df745b (patch) | |
tree | f8d48c4c67fed981257fc2dcdf976e38425ad3d0 /drivers | |
parent | net: rmnet: fix NULL pointer dereference in rmnet_changelink() (diff) | |
download | linux-102210f7664442d8c0ce332c006ea90626df745b.tar.gz linux-102210f7664442d8c0ce332c006ea90626df745b.tar.bz2 linux-102210f7664442d8c0ce332c006ea90626df745b.zip |
net: rmnet: fix suspicious RCU usage
rmnet_get_port() internally calls rcu_dereference_rtnl(),
which checks RTNL.
But rmnet_get_port() could be called by packet path.
The packet path is not protected by RTNL.
So, the suspicious RCU usage problem occurs.
Test commands:
modprobe rmnet
ip netns add nst
ip link add veth0 type veth peer name veth1
ip link set veth1 netns nst
ip link add rmnet0 link veth0 type rmnet mux_id 1
ip netns exec nst ip link add rmnet1 link veth1 type rmnet mux_id 1
ip netns exec nst ip link set veth1 up
ip netns exec nst ip link set rmnet1 up
ip netns exec nst ip a a 192.168.100.2/24 dev rmnet1
ip link set veth0 up
ip link set rmnet0 up
ip a a 192.168.100.1/24 dev rmnet0
ping 192.168.100.2
Splat looks like:
[ 146.630958][ T1174] WARNING: suspicious RCU usage
[ 146.631735][ T1174] 5.6.0-rc1+ #447 Not tainted
[ 146.632387][ T1174] -----------------------------
[ 146.633151][ T1174] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:386 suspicious rcu_dereference_check() !
[ 146.634742][ T1174]
[ 146.634742][ T1174] other info that might help us debug this:
[ 146.634742][ T1174]
[ 146.645992][ T1174]
[ 146.645992][ T1174] rcu_scheduler_active = 2, debug_locks = 1
[ 146.646937][ T1174] 5 locks held by ping/1174:
[ 146.647609][ T1174] #0: ffff8880c31dea70 (sk_lock-AF_INET){+.+.}, at: raw_sendmsg+0xab8/0x2980
[ 146.662463][ T1174] #1: ffffffff93925660 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x243/0x2150
[ 146.671696][ T1174] #2: ffffffff93925660 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x213/0x2940
[ 146.673064][ T1174] #3: ffff8880c19ecd58 (&dev->qdisc_running_key#7){+...}, at: ip_finish_output2+0x714/0x2150
[ 146.690358][ T1174] #4: ffff8880c5796898 (&dev->qdisc_xmit_lock_key#3){+.-.}, at: sch_direct_xmit+0x1e2/0x1020
[ 146.699875][ T1174]
[ 146.699875][ T1174] stack backtrace:
[ 146.701091][ T1174] CPU: 0 PID: 1174 Comm: ping Not tainted 5.6.0-rc1+ #447
[ 146.705215][ T1174] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 146.706565][ T1174] Call Trace:
[ 146.707102][ T1174] dump_stack+0x96/0xdb
[ 146.708007][ T1174] rmnet_get_port.part.9+0x76/0x80 [rmnet]
[ 146.709233][ T1174] rmnet_egress_handler+0x107/0x420 [rmnet]
[ 146.710492][ T1174] ? sch_direct_xmit+0x1e2/0x1020
[ 146.716193][ T1174] rmnet_vnd_start_xmit+0x3d/0xa0 [rmnet]
[ 146.717012][ T1174] dev_hard_start_xmit+0x160/0x740
[ 146.717854][ T1174] sch_direct_xmit+0x265/0x1020
[ 146.718577][ T1174] ? register_lock_class+0x14d0/0x14d0
[ 146.719429][ T1174] ? dev_watchdog+0xac0/0xac0
[ 146.723738][ T1174] ? __dev_queue_xmit+0x15fd/0x2940
[ 146.724469][ T1174] ? lock_acquire+0x164/0x3b0
[ 146.725172][ T1174] __dev_queue_xmit+0x20c7/0x2940
[ ... ]
Fixes: ceed73a2cf4a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c | 13 | ||||
-rw-r--r-- | drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h | 2 | ||||
-rw-r--r-- | drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 4 |
3 files changed, 9 insertions, 10 deletions
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c index ac58f584190b..fc68ecdd804b 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c @@ -382,11 +382,10 @@ struct rtnl_link_ops rmnet_link_ops __read_mostly = { .fill_info = rmnet_fill_info, }; -/* Needs either rcu_read_lock() or rtnl lock */ -struct rmnet_port *rmnet_get_port(struct net_device *real_dev) +struct rmnet_port *rmnet_get_port_rcu(struct net_device *real_dev) { if (rmnet_is_real_dev_registered(real_dev)) - return rcu_dereference_rtnl(real_dev->rx_handler_data); + return rcu_dereference_bh(real_dev->rx_handler_data); else return NULL; } @@ -412,7 +411,7 @@ int rmnet_add_bridge(struct net_device *rmnet_dev, struct rmnet_port *port, *slave_port; int err; - port = rmnet_get_port(real_dev); + port = rmnet_get_port_rtnl(real_dev); /* If there is more than one rmnet dev attached, its probably being * used for muxing. Skip the briding in that case @@ -427,7 +426,7 @@ int rmnet_add_bridge(struct net_device *rmnet_dev, if (err) return -EBUSY; - slave_port = rmnet_get_port(slave_dev); + slave_port = rmnet_get_port_rtnl(slave_dev); slave_port->rmnet_mode = RMNET_EPMODE_BRIDGE; slave_port->bridge_ep = real_dev; @@ -445,11 +444,11 @@ int rmnet_del_bridge(struct net_device *rmnet_dev, struct net_device *real_dev = priv->real_dev; struct rmnet_port *port, *slave_port; - port = rmnet_get_port(real_dev); + port = rmnet_get_port_rtnl(real_dev); port->rmnet_mode = RMNET_EPMODE_VND; port->bridge_ep = NULL; - slave_port = rmnet_get_port(slave_dev); + slave_port = rmnet_get_port_rtnl(slave_dev); rmnet_unregister_real_device(slave_dev, slave_port); netdev_dbg(slave_dev, "removed from rmnet as slave\n"); diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h index cd0a6bcbe74a..0d568dcfd65a 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h @@ -65,7 +65,7 @@ struct rmnet_priv { struct rmnet_priv_stats stats; }; -struct rmnet_port *rmnet_get_port(struct net_device *real_dev); +struct rmnet_port *rmnet_get_port_rcu(struct net_device *real_dev); struct rmnet_endpoint *rmnet_get_endpoint(struct rmnet_port *port, u8 mux_id); int rmnet_add_bridge(struct net_device *rmnet_dev, struct net_device *slave_dev, diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c index 1b74bc160402..074a8b326c30 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c @@ -184,7 +184,7 @@ rx_handler_result_t rmnet_rx_handler(struct sk_buff **pskb) return RX_HANDLER_PASS; dev = skb->dev; - port = rmnet_get_port(dev); + port = rmnet_get_port_rcu(dev); switch (port->rmnet_mode) { case RMNET_EPMODE_VND: @@ -217,7 +217,7 @@ void rmnet_egress_handler(struct sk_buff *skb) skb->dev = priv->real_dev; mux_id = priv->mux_id; - port = rmnet_get_port(skb->dev); + port = rmnet_get_port_rcu(skb->dev); if (!port) goto drop; |