hsr: Handle failures in module init

[ Upstream commit 3cf28cd492308e5f63ed00b29ea03ca016264376 ]

A failure during registration of the netdev notifier was not handled at
all. A failure during netlink initialization did not unregister the netdev
notifier.

Handle failures of netdev notifier registration and netlink initialization.
Both functions should only return negative values on failure and thereby
lead to the hsr module not being loaded.

Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/3ce097c15e3f7ace98fc7fd9bcbf299f092e63d1.1710504184.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/hsr/hsr_main.c b/net/hsr/hsr_main.c
index cd37d0011b424824fd113ffd4da59f36c116996a..c22013ff447950a96079f016cd87305fa41433a0 100644 (file)
--- a/net/hsr/hsr_main.c
+++ b/net/hsr/hsr_main.c
@@ -115,14 +115,21 @@ static struct notifier_block hsr_nb = {
 
 static int __init hsr_init(void)
 {
-       int res;
+       int err;
 
        BUILD_BUG_ON(sizeof(struct hsr_tag) != HSR_HLEN);
 
-       register_netdevice_notifier(&hsr_nb);
-       res = hsr_netlink_init();
+       err = register_netdevice_notifier(&hsr_nb);
+       if (err)
+               return err;
+
+       err = hsr_netlink_init();
+       if (err) {
+               unregister_netdevice_notifier(&hsr_nb);
+               return err;
+       }
 
-       return res;
+       return 0;
 }
 
 static void __exit hsr_exit(void)