From 931027820e4dafabc78aff82af59f8c1c4bd3128 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 29 Jul 2022 09:12:32 +0000 Subject: net: rose: fix netdev reference changes Bernard reported that trying to unload rose module would lead to infamous messages: unregistered_netdevice: waiting for rose0 to become free. Usage count = xx This patch solves the issue, by making sure each socket referring to a netdevice holds a reference count on it, and properly releases it in rose_release(). rose_dev_first() is also fixed to take a device reference before leaving the rcu_read_locked section. Following patch will add ref_tracker annotations to ease future bug hunting. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Bernard Pidoux Signed-off-by: Eric Dumazet Tested-by: Bernard Pidoux Signed-off-by: Jakub Kicinski --- net/rose/rose_route.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/rose/rose_route.c') diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c index eb0b8197ac82..fee772b4637c 100644 --- a/net/rose/rose_route.c +++ b/net/rose/rose_route.c @@ -615,6 +615,8 @@ struct net_device *rose_dev_first(void) if (first == NULL || strncmp(dev->name, first->name, 3) < 0) first = dev; } + if (first) + dev_hold(first); rcu_read_unlock(); return first; -- cgit v1.2.3-59-g8ed1b