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* [PATCH net-next 1/1] ethtool/plca: fix potential NULL pointer access
@ 2023-01-16 23:57 Piergiorgio Beruto
  2023-01-17  0:34 ` Vladimir Oltean
  0 siblings, 1 reply; 3+ messages in thread
From: Piergiorgio Beruto @ 2023-01-16 23:57 UTC (permalink / raw)
  To: Andrew Lunn, Heiner Kallweit, Russell King, David S. Miller,
	Eric Dumazet, Jakub Kicinski, Paolo Abeni
  Cc: linux-kernel, netdev, Oleksij Rempel, mailhol.vincent,
	sudheer.mogilappagari, sbhatta, linux-doc, wangjie125, corbet,
	lkp, gal, gustavoars, bagasdotme

Fix problem found by syzbot dereferencing a device pointer.

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
Reported-by: syzbot+8cf35743af243e5f417e@syzkaller.appspotmail.com
Fixes: 8580e16c28f3 ("net/ethtool: add netlink interface for the PLCA RS")
---
 net/ethtool/plca.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ethtool/plca.c b/net/ethtool/plca.c
index be7404dc9ef2..bc3d31f99998 100644
--- a/net/ethtool/plca.c
+++ b/net/ethtool/plca.c
@@ -155,6 +155,8 @@ int ethnl_set_plca_cfg(struct sk_buff *skb, struct genl_info *info)
 		return ret;
 
 	dev = req_info.dev;
+	if(!dev)
+		return -ENODEV;
 
 	rtnl_lock();
 
-- 
2.37.4


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH net-next 1/1] ethtool/plca: fix potential NULL pointer access
  2023-01-16 23:57 [PATCH net-next 1/1] ethtool/plca: fix potential NULL pointer access Piergiorgio Beruto
@ 2023-01-17  0:34 ` Vladimir Oltean
  2023-01-17  9:13   ` Piergiorgio Beruto
  0 siblings, 1 reply; 3+ messages in thread
From: Vladimir Oltean @ 2023-01-17  0:34 UTC (permalink / raw)
  To: Piergiorgio Beruto
  Cc: Andrew Lunn, Heiner Kallweit, Russell King, David S. Miller,
	Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-kernel, netdev,
	Oleksij Rempel, mailhol.vincent, sudheer.mogilappagari, sbhatta,
	linux-doc, wangjie125, corbet, lkp, gal, gustavoars, bagasdotme

On Tue, Jan 17, 2023 at 12:57:19AM +0100, Piergiorgio Beruto wrote:
> Fix problem found by syzbot dereferencing a device pointer.
> 
> Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
> Reported-by: syzbot+8cf35743af243e5f417e@syzkaller.appspotmail.com
> Fixes: 8580e16c28f3 ("net/ethtool: add netlink interface for the PLCA RS")
> ---
>  net/ethtool/plca.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/ethtool/plca.c b/net/ethtool/plca.c
> index be7404dc9ef2..bc3d31f99998 100644
> --- a/net/ethtool/plca.c
> +++ b/net/ethtool/plca.c
> @@ -155,6 +155,8 @@ int ethnl_set_plca_cfg(struct sk_buff *skb, struct genl_info *info)
>  		return ret;
>  
>  	dev = req_info.dev;
> +	if(!dev)
> +		return -ENODEV;

Shouldn't be necessary. The fact that you pass "true" to the
"require_dev" argument of ethnl_parse_header_dev_get() takes care
specifically of that.

Looking at that syzbot report, it looks like you solved it with commit
28dbf774bc87 ("plca.c: fix obvious mistake in checking retval"). Or was
that not the only issue?

>  
>  	rtnl_lock();
>  
> -- 
> 2.37.4
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH net-next 1/1] ethtool/plca: fix potential NULL pointer access
  2023-01-17  0:34 ` Vladimir Oltean
@ 2023-01-17  9:13   ` Piergiorgio Beruto
  0 siblings, 0 replies; 3+ messages in thread
From: Piergiorgio Beruto @ 2023-01-17  9:13 UTC (permalink / raw)
  To: Vladimir Oltean
  Cc: Andrew Lunn, Heiner Kallweit, Russell King, David S. Miller,
	Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-kernel, netdev,
	Oleksij Rempel, mailhol.vincent, sudheer.mogilappagari, sbhatta,
	linux-doc, wangjie125, corbet, lkp, gal, gustavoars, bagasdotme

On Tue, Jan 17, 2023 at 02:34:26AM +0200, Vladimir Oltean wrote:
> On Tue, Jan 17, 2023 at 12:57:19AM +0100, Piergiorgio Beruto wrote:
> > Fix problem found by syzbot dereferencing a device pointer.
> > 
> > Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
> > Reported-by: syzbot+8cf35743af243e5f417e@syzkaller.appspotmail.com
> > Fixes: 8580e16c28f3 ("net/ethtool: add netlink interface for the PLCA RS")
> > ---
> >  net/ethtool/plca.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/net/ethtool/plca.c b/net/ethtool/plca.c
> > index be7404dc9ef2..bc3d31f99998 100644
> > --- a/net/ethtool/plca.c
> > +++ b/net/ethtool/plca.c
> > @@ -155,6 +155,8 @@ int ethnl_set_plca_cfg(struct sk_buff *skb, struct genl_info *info)
> >  		return ret;
> >  
> >  	dev = req_info.dev;
> > +	if(!dev)
> > +		return -ENODEV;
> 
> Shouldn't be necessary. The fact that you pass "true" to the
> "require_dev" argument of ethnl_parse_header_dev_get() takes care
> specifically of that.
> 
> Looking at that syzbot report, it looks like you solved it with commit
> 28dbf774bc87 ("plca.c: fix obvious mistake in checking retval"). Or was
> that not the only issue?
Oh, I believe you are correct.
I probably confused which version the bug was reported against.

Please, ignore this patch...
Thanks!

Piergiorgio

> 
> >  
> >  	rtnl_lock();
> >  
> > -- 
> > 2.37.4
> > 

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2023-01-17  9:19 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2023-01-16 23:57 [PATCH net-next 1/1] ethtool/plca: fix potential NULL pointer access Piergiorgio Beruto
2023-01-17  0:34 ` Vladimir Oltean
2023-01-17  9:13   ` Piergiorgio Beruto

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