net: netdevsim: try to close UDP port harness races

[ Upstream commit 50bf398e1ceacb9a7f85bd3bdca065ebe5cb6159 ]

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: 424be63ad8 ("netdevsim: add UDP tunnel port offload support")
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://patch.msgid.link/20250122224503.762705-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jakub Kicinski 2025-01-22 14:45:03 -08:00 committed by Greg Kroah-Hartman
parent f55c88e3ca
commit d3c1025ed7
3 changed files with 23 additions and 17 deletions

View File

@ -98,6 +98,7 @@ 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;

View File

@ -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;
}

View File

@ -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/
@ -640,7 +640,7 @@ for port in 0 1; do
NSIM_NETDEV=`get_netdev_name old_netdevs`
ifconfig $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 )
@ -662,7 +662,7 @@ 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
@ -763,7 +763,7 @@ 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"
@ -774,7 +774,7 @@ 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"
@ -788,7 +788,7 @@ 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"
@ -895,7 +895,7 @@ 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"