syzbot discovered that we remove the debugfs files after we free the netdev. Try to clean up the relevant dir while the device is still around.

Reported-by: syzbot+2e5de9e3ab986b71d2bf@syzkaller.appspotmail.com Fixes: 424be63ad831 ("netdevsim: add UDP tunnel port offload support") Signed-off-by: Jakub Kicinski kuba@kernel.org --- CC: shuah@kernel.org CC: linux-kselftest@vger.kernel.org --- drivers/net/netdevsim/netdevsim.h | 1 + drivers/net/netdevsim/udp_tunnels.c | 23 +++++++++++-------- .../drivers/net/netdevsim/udp_tunnel_nic.sh | 16 ++++++------- 3 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h index dcf073bc4802..96d54c08043d 100644 --- a/drivers/net/netdevsim/netdevsim.h +++ b/drivers/net/netdevsim/netdevsim.h @@ -134,6 +134,7 @@ struct netdevsim { u32 sleep; u32 __ports[2][NSIM_UDP_TUNNEL_N_PORTS]; u32 (*ports)[NSIM_UDP_TUNNEL_N_PORTS]; + struct dentry *ddir; struct debugfs_u32_array dfs_ports[2]; } udp_ports;

diff --git a/drivers/net/netdevsim/udp_tunnels.c b/drivers/net/netdevsim/udp_tunnels.c index 02dc3123eb6c..640b4983a9a0 100644 --- a/drivers/net/netdevsim/udp_tunnels.c +++ b/drivers/net/netdevsim/udp_tunnels.c @@ -112,9 +112,11 @@ nsim_udp_tunnels_info_reset_write(struct file *file, const char __user *data, struct net_device *dev = file->private_data; struct netdevsim *ns = netdev_priv(dev);

- memset(ns->udp_ports.ports, 0, sizeof(ns->udp_ports.__ports)); rtnl_lock(); - udp_tunnel_nic_reset_ntf(dev); + if (dev->reg_state == NETREG_REGISTERED) { + memset(ns->udp_ports.ports, 0, sizeof(ns->udp_ports.__ports)); + udp_tunnel_nic_reset_ntf(dev); + } rtnl_unlock();

return count; @@ -144,23 +146,23 @@ int nsim_udp_tunnels_info_create(struct nsim_dev *nsim_dev, else ns->udp_ports.ports = nsim_dev->udp_ports.__ports;

- debugfs_create_u32("udp_ports_inject_error", 0600, - ns->nsim_dev_port->ddir, + ns->udp_ports.ddir = debugfs_create_dir("udp_ports", + ns->nsim_dev_port->ddir); + + debugfs_create_u32("inject_error", 0600, ns->udp_ports.ddir, &ns->udp_ports.inject_error);

ns->udp_ports.dfs_ports[0].array = ns->udp_ports.ports[0]; ns->udp_ports.dfs_ports[0].n_elements = NSIM_UDP_TUNNEL_N_PORTS; - debugfs_create_u32_array("udp_ports_table0", 0400, - ns->nsim_dev_port->ddir, + debugfs_create_u32_array("table0", 0400, ns->udp_ports.ddir, &ns->udp_ports.dfs_ports[0]);

ns->udp_ports.dfs_ports[1].array = ns->udp_ports.ports[1]; ns->udp_ports.dfs_ports[1].n_elements = NSIM_UDP_TUNNEL_N_PORTS; - debugfs_create_u32_array("udp_ports_table1", 0400, - ns->nsim_dev_port->ddir, + debugfs_create_u32_array("table1", 0400, ns->udp_ports.ddir, &ns->udp_ports.dfs_ports[1]);

- debugfs_create_file("udp_ports_reset", 0200, ns->nsim_dev_port->ddir, + debugfs_create_file("reset", 0200, ns->udp_ports.ddir, dev, &nsim_udp_tunnels_info_reset_fops);

/* Note: it's not normal to allocate the info struct like this! @@ -196,6 +198,9 @@ int nsim_udp_tunnels_info_create(struct nsim_dev *nsim_dev,

void nsim_udp_tunnels_info_destroy(struct net_device *dev) { + struct netdevsim *ns = netdev_priv(dev); + + debugfs_remove_recursive(ns->udp_ports.ddir); kfree(dev->udp_tunnel_nic_info); dev->udp_tunnel_nic_info = NULL; } diff --git a/tools/testing/selftests/drivers/net/netdevsim/udp_tunnel_nic.sh b/tools/testing/selftests/drivers/net/netdevsim/udp_tunnel_nic.sh index 384cfa3d38a6..92c2f0376c08 100755 --- a/tools/testing/selftests/drivers/net/netdevsim/udp_tunnel_nic.sh +++ b/tools/testing/selftests/drivers/net/netdevsim/udp_tunnel_nic.sh @@ -142,7 +142,7 @@ function pre_ethtool { }

function check_table { - local path=$NSIM_DEV_DFS/ports/$port/udp_ports_table$1 + local path=$NSIM_DEV_DFS/ports/$port/udp_ports/table$1 local -n expected=$2 local last=$3

@@ -212,7 +212,7 @@ function check_tables { }

function print_table { - local path=$NSIM_DEV_DFS/ports/$port/udp_ports_table$1 + local path=$NSIM_DEV_DFS/ports/$port/udp_ports/table$1 read -a have < $path

tree $NSIM_DEV_DFS/ @@ -641,7 +641,7 @@ for port in 0 1; do NSIM_NETDEV=`get_netdev_name old_netdevs` ip link set dev $NSIM_NETDEV up

- echo 110 > $NSIM_DEV_DFS/ports/$port/udp_ports_inject_error + echo 110 > $NSIM_DEV_DFS/ports/$port/udp_ports/inject_error

msg="1 - create VxLANs v6" exp0=( 0 0 0 0 ) @@ -663,7 +663,7 @@ for port in 0 1; do new_geneve gnv0 20000

msg="2 - destroy GENEVE" - echo 2 > $NSIM_DEV_DFS/ports/$port/udp_ports_inject_error + echo 2 > $NSIM_DEV_DFS/ports/$port/udp_ports/inject_error exp1=( `mke 20000 2` 0 0 0 ) del_dev gnv0

@@ -764,7 +764,7 @@ for port in 0 1; do msg="create VxLANs v4" new_vxlan vxlan0 10000 $NSIM_NETDEV

- echo 1 > $NSIM_DEV_DFS/ports/$port/udp_ports_reset + echo 1 > $NSIM_DEV_DFS/ports/$port/udp_ports/reset check_tables

msg="NIC device goes down" @@ -775,7 +775,7 @@ for port in 0 1; do fi check_tables

- echo 1 > $NSIM_DEV_DFS/ports/$port/udp_ports_reset + echo 1 > $NSIM_DEV_DFS/ports/$port/udp_ports/reset check_tables

msg="NIC device goes up again" @@ -789,7 +789,7 @@ for port in 0 1; do del_dev vxlan0 check_tables

- echo 1 > $NSIM_DEV_DFS/ports/$port/udp_ports_reset + echo 1 > $NSIM_DEV_DFS/ports/$port/udp_ports/reset check_tables

msg="destroy NIC" @@ -896,7 +896,7 @@ msg="vacate VxLAN in overflow table" exp0=( `mke 10000 1` `mke 10004 1` 0 `mke 10003 1` ) del_dev vxlan2

-echo 1 > $NSIM_DEV_DFS/ports/$port/udp_ports_reset +echo 1 > $NSIM_DEV_DFS/ports/$port/udp_ports/reset check_tables

msg="tunnels destroyed 2"