[PATCH 4.14 16/77] xfrm: Fix ignored return value in xfrm6_init()

Greg Kroah-Hartman
2022-12-05T19:16:09Z

From: Chen Zhongjin <chenzhongjin@huawei.com>

[ Upstream commit 40781bfb836eda57d19c0baa37c7e72590e05fdc ]

When IPv6 module initializing in xfrm6_init(), register_pernet_subsys()
is possible to fail but its return value is ignored.

If IPv6 initialization fails later and xfrm6_fini() is called,
removing uninitialized list in xfrm6_net_ops will cause null-ptr-deref:

KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 330 Comm: insmod
RIP: 0010:unregister_pernet_operations+0xc9/0x450
Call Trace:
<TASK>
unregister_pernet_subsys+0x31/0x3e
xfrm6_fini+0x16/0x30 [ipv6]
ip6_route_init+0xcd/0x128 [ipv6]
inet6_init+0x29c/0x602 [ipv6]
...

Fix it by catching the error return value of register_pernet_subsys().

Fixes: 8d068875caca ("xfrm: make gc_thresh configurable in all namespaces")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv6/xfrm6_policy.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index b0d80cef7c2b..44d616d0bd00 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -412,9 +412,13 @@ int __init xfrm6_init(void)
if (ret)
goto out_state;

- register_pernet_subsys(&xfrm6_net_ops);
+ ret = register_pernet_subsys(&xfrm6_net_ops);
+ if (ret)
+ goto out_protocol;
out:
return ret;
+out_protocol:
+ xfrm6_protocol_fini();
out_state:
xfrm6_state_fini();
out_policy:
--
2.35.1