Messages in this thread | | | From | Eric Dumazet <> | Date | Fri, 22 Jul 2022 19:05:34 +0200 | Subject | Re: [PATCH] net: rose: fix unregistered netdevice: waiting for rose0 to become free |
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On Fri, Jul 22, 2022 at 6:41 PM Bernard f6bvp <f6bvp@free.fr> wrote: > > Here is the context. > > This patch adds dev_put(dev) in order to allow removal of rose module > after use of AX25 and ROSE via rose0 device. > > Otherwise when trying to remove rose module via rmmod rose an infinite > loop message was displayed on all consoles with xx being a random number. > > unregistered_netdevice: waiting for rose0 to become free. Usage count = xx > > unregistered_netdevice: waiting for rose0 to become free. Usage count = xx > > ... > > With the patch it is ok to rmmod rose. > > This bug appeared with kernel 4.10 and has been only partially repaired > by adding two dev_put(dev). > > Signed-off-by: Bernard Pidoux <f6bvp@free.fr> > > --- > net/rose/af_rose.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c > index bf2d986a6bc3..4163171ce3a6 100644 > --- a/net/rose/af_rose.c > +++ b/net/rose/af_rose.c > @@ -711,6 +711,8 @@ static int rose_bind(struct socket *sock, struct > sockaddr *uaddr, int addr_len) > rose_insert_socket(sk); > > sock_reset_flag(sk, SOCK_ZAPPED); > + > + dev_put(dev);
But, we have at line 698 :
rose->device = dev;
So we can not keep a pointer to a device without holding a reference on it.
As a bonus we could convert these dev_put() to new infra added with CONFIG_NET_DEV_REFCNT_TRACKER=y
> > return 0; > } > -- > 2.34.1 > > [master da21d19e920d] [PATCH] net: rose: fix unregistered netdevice: > waiting for rose0 to become free > Date: Mon Jul 18 16:23:54 2022 +0200 > 1 file changed, 2 insertions(+) > >
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