netdevsim: Fix error handling in nsim_fib_init and nsim_fib_exit
In nsim_fib_init(), if register_fib_notifier failed, nsim_fib_net_ops
should be unregistered before return.
In nsim_fib_exit(), unregister_fib_notifier should be called before
nsim_fib_net_ops be unregistered, otherwise may cause use-after-free:
BUG: KASAN: use-after-free in nsim_fib_event_nb+0x342/0x570 [netdevsim]
Read of size 8 at addr ffff8881daaf4388 by task kworker/0:3/3499
CPU: 0 PID: 3499 Comm: kworker/0:3 Not tainted 5.3.0-rc7+ #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work [ipv6]
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xa9/0x10e lib/dump_stack.c:113
print_address_description+0x65/0x380 mm/kasan/report.c:351
__kasan_report+0x149/0x18d mm/kasan/report.c:482
kasan_report+0xe/0x20 mm/kasan/common.c:618
nsim_fib_event_nb+0x342/0x570 [netdevsim]
notifier_call_chain+0x52/0xf0 kernel/notifier.c:95
__atomic_notifier_call_chain+0x78/0x140 kernel/notifier.c:185
call_fib_notifiers+0x30/0x60 net/core/fib_notifier.c:30
call_fib6_entry_notifiers+0xc1/0x100 [ipv6]
fib6_add+0x92e/0x1b10 [ipv6]
__ip6_ins_rt+0x40/0x60 [ipv6]
ip6_ins_rt+0x84/0xb0 [ipv6]
__ipv6_ifa_notify+0x4b6/0x550 [ipv6]
ipv6_ifa_notify+0xa5/0x180 [ipv6]
addrconf_dad_completed+0xca/0x640 [ipv6]
addrconf_dad_work+0x296/0x960 [ipv6]
process_one_work+0x5c0/0xc00 kernel/workqueue.c:2269
worker_thread+0x5c/0x670 kernel/workqueue.c:2415
kthread+0x1d7/0x200 kernel/kthread.c:255
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Allocated by task 3388:
save_stack+0x19/0x80 mm/kasan/common.c:69
set_track mm/kasan/common.c:77 [inline]
__kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:493
kmalloc include/linux/slab.h:557 [inline]
kzalloc include/linux/slab.h:748 [inline]
ops_init+0xa9/0x220 net/core/net_namespace.c:127
__register_pernet_operations net/core/net_namespace.c:1135 [inline]
register_pernet_operations+0x1d4/0x420 net/core/net_namespace.c:1212
register_pernet_subsys+0x24/0x40 net/core/net_namespace.c:1253
nsim_fib_init+0x12/0x70 [netdevsim]
veth_get_link_ksettings+0x2b/0x50 [veth]
do_one_initcall+0xd4/0x454 init/main.c:939
do_init_module+0xe0/0x330 kernel/module.c:3490
load_module+0x3c2f/0x4620 kernel/module.c:3841
__do_sys_finit_module+0x163/0x190 kernel/module.c:3931
do_syscall_64+0x72/0x2e0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 3534:
save_stack+0x19/0x80 mm/kasan/common.c:69
set_track mm/kasan/common.c:77 [inline]
__kasan_slab_free+0x130/0x180 mm/kasan/common.c:455
slab_free_hook mm/slub.c:1423 [inline]
slab_free_freelist_hook mm/slub.c:1474 [inline]
slab_free mm/slub.c:3016 [inline]
kfree+0xe9/0x2d0 mm/slub.c:3957
ops_free net/core/net_namespace.c:151 [inline]
ops_free_list.part.7+0x156/0x220 net/core/net_namespace.c:184
ops_free_list net/core/net_namespace.c:182 [inline]
__unregister_pernet_operations net/core/net_namespace.c:1165 [inline]
unregister_pernet_operations+0x221/0x2a0 net/core/net_namespace.c:1224
unregister_pernet_subsys+0x1d/0x30 net/core/net_namespace.c:1271
nsim_fib_exit+0x11/0x20 [netdevsim]
nsim_module_exit+0x16/0x21 [netdevsim]
__do_sys_delete_module kernel/module.c:1015 [inline]
__se_sys_delete_module kernel/module.c:958 [inline]
__x64_sys_delete_module+0x244/0x330 kernel/module.c:958
do_syscall_64+0x72/0x2e0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 59c84b9fcf42 ("netdevsim: Restore per-network namespace accounting for fib entries")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/netdevsim/fib.c b/drivers/net/netdevsim/fib.c
index f61d094..1a251f7 100644
--- a/drivers/net/netdevsim/fib.c
+++ b/drivers/net/netdevsim/fib.c
@@ -241,8 +241,8 @@ static struct pernet_operations nsim_fib_net_ops = {
void nsim_fib_exit(void)
{
- unregister_pernet_subsys(&nsim_fib_net_ops);
unregister_fib_notifier(&nsim_fib_nb);
+ unregister_pernet_subsys(&nsim_fib_net_ops);
}
int nsim_fib_init(void)
@@ -258,6 +258,7 @@ int nsim_fib_init(void)
err = register_fib_notifier(&nsim_fib_nb, nsim_fib_dump_inconsistent);
if (err < 0) {
pr_err("Failed to register fib notifier\n");
+ unregister_pernet_subsys(&nsim_fib_net_ops);
goto err_out;
}
