diff mbox

[net] tuntap: correctly handle error in tun_set_iff()

Message ID 1378887845-6821-1-git-send-email-jasowang@redhat.com
State Superseded, archived
Delegated to: David Miller
Headers show

Commit Message

Jason Wang Sept. 11, 2013, 8:24 a.m. UTC
Commit c8d68e6be1c3b242f1c598595830890b65cea64a (tuntap: multiqueue support)
only call free_netdev() on err in tun_set_iff(). This causes several issues:

- memory of tun security were leaked
- use after free since the flow gc timer was not deleted and the tfile were not
  detached

This patch solves the above issues.

Reported-by: Wannes Rombouts <wannes.rombouts@epitech.eu>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
The patch were also needed for stable 3.8+.
---
 drivers/net/tun.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

Comments

Michael S. Tsirkin Sept. 11, 2013, 9:38 a.m. UTC | #1
On Wed, Sep 11, 2013 at 04:24:05PM +0800, Jason Wang wrote:
> Commit c8d68e6be1c3b242f1c598595830890b65cea64a (tuntap: multiqueue support)
> only call free_netdev() on err in tun_set_iff(). This causes several issues:
> 
> - memory of tun security were leaked

Not just tun security -  sock reference too (didn't detach)

> - use after free since the flow gc timer was not deleted and the tfile were not
>   detached
> 
> This patch solves the above issues.
> 
> Reported-by: Wannes Rombouts <wannes.rombouts@epitech.eu>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> The patch were also needed for stable 3.8+.
> ---
>  drivers/net/tun.c |    9 +++++++--
>  1 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index a639de8..e5fb5d3 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -1641,11 +1641,11 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
>  		INIT_LIST_HEAD(&tun->disabled);
>  		err = tun_attach(tun, file, false);
>  		if (err < 0)
> -			goto err_free_dev;
> +			goto err_free_flow;
>  
>  		err = register_netdevice(tun->dev);
>  		if (err < 0)
> -			goto err_free_dev;
> +			goto err_detach;
>  
>  		if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
>  		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
> @@ -1689,6 +1689,11 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
>  	strcpy(ifr->ifr_name, tun->dev->name);
>  	return 0;
>  
> +err_detach:
> +	tun_detach_all(dev);
> +err_free_flow:
> +	tun_flow_uninit(tun);
> +	security_tun_dev_free_security(tun->security);

This bit looks wrong: if flow_init fails, we
need security_tun_dev_free_security, don't we?
I think we need:
	+err_free_sec:	security_tun_dev_free_security(tun->security);
and goto here on flow_init failures.

>   err_free_dev:

Pls shift this one 1 space left for consistency.

>  	free_netdev(dev);
>  	return err;
> -- 
> 1.7.1
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Jason Wang Sept. 11, 2013, 9:55 a.m. UTC | #2
----- Original Message -----
> On Wed, Sep 11, 2013 at 04:24:05PM +0800, Jason Wang wrote:
> > Commit c8d68e6be1c3b242f1c598595830890b65cea64a (tuntap: multiqueue
> > support)
> > only call free_netdev() on err in tun_set_iff(). This causes several
> > issues:
> > 
> > - memory of tun security were leaked
> 
> Not just tun security -  sock reference too (didn't detach)
> 

Yes, I mention it in the next item.
> > - use after free since the flow gc timer was not deleted and the tfile were
> > not
> >   detached
> > 
> > This patch solves the above issues.
> > 
> > Reported-by: Wannes Rombouts <wannes.rombouts@epitech.eu>
> > Cc: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > ---
> > The patch were also needed for stable 3.8+.
> > ---
> >  drivers/net/tun.c |    9 +++++++--
> >  1 files changed, 7 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > index a639de8..e5fb5d3 100644
> > --- a/drivers/net/tun.c
> > +++ b/drivers/net/tun.c
> > @@ -1641,11 +1641,11 @@ static int tun_set_iff(struct net *net, struct file
> > *file, struct ifreq *ifr)
> >  		INIT_LIST_HEAD(&tun->disabled);
> >  		err = tun_attach(tun, file, false);
> >  		if (err < 0)
> > -			goto err_free_dev;
> > +			goto err_free_flow;
> >  
> >  		err = register_netdevice(tun->dev);
> >  		if (err < 0)
> > -			goto err_free_dev;
> > +			goto err_detach;
> >  
> >  		if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
> >  		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
> > @@ -1689,6 +1689,11 @@ static int tun_set_iff(struct net *net, struct file
> > *file, struct ifreq *ifr)
> >  	strcpy(ifr->ifr_name, tun->dev->name);
> >  	return 0;
> >  
> > +err_detach:
> > +	tun_detach_all(dev);
> > +err_free_flow:
> > +	tun_flow_uninit(tun);
> > +	security_tun_dev_free_security(tun->security);
> 
> This bit looks wrong: if flow_init fails, we
> need security_tun_dev_free_security, don't we?
> I think we need:
> 	+err_free_sec:	security_tun_dev_free_security(tun->security);
> and goto here on flow_init failures.

tun_flow_init() always succeed. So we're ok here.
> 
> >   err_free_dev:
> 
> Pls shift this one 1 space left for consistency.
> 

Ok.
> >  	free_netdev(dev);
> >  	return err;
> > --
> > 1.7.1
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
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> 
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Michael S. Tsirkin Sept. 11, 2013, 10:08 a.m. UTC | #3
On Wed, Sep 11, 2013 at 05:55:04AM -0400, Jason Wang wrote:
> 
> 
> ----- Original Message -----
> > On Wed, Sep 11, 2013 at 04:24:05PM +0800, Jason Wang wrote:
> > > Commit c8d68e6be1c3b242f1c598595830890b65cea64a (tuntap: multiqueue
> > > support)
> > > only call free_netdev() on err in tun_set_iff(). This causes several
> > > issues:
> > > 
> > > - memory of tun security were leaked
> > 
> > Not just tun security -  sock reference too (didn't detach)
> > 
> 
> Yes, I mention it in the next item.

That line's a bit too long btw.
Keep it under 70 chars for commit logs.

> > > - use after free since the flow gc timer was not deleted and the tfile were
> > > not
> > >   detached
> > > 
> > > This patch solves the above issues.
> > > 
> > > Reported-by: Wannes Rombouts <wannes.rombouts@epitech.eu>
> > > Cc: Michael S. Tsirkin <mst@redhat.com>
> > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > ---
> > > The patch were also needed for stable 3.8+.
> > > ---
> > >  drivers/net/tun.c |    9 +++++++--
> > >  1 files changed, 7 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > > index a639de8..e5fb5d3 100644
> > > --- a/drivers/net/tun.c
> > > +++ b/drivers/net/tun.c
> > > @@ -1641,11 +1641,11 @@ static int tun_set_iff(struct net *net, struct file
> > > *file, struct ifreq *ifr)
> > >  		INIT_LIST_HEAD(&tun->disabled);
> > >  		err = tun_attach(tun, file, false);
> > >  		if (err < 0)
> > > -			goto err_free_dev;
> > > +			goto err_free_flow;
> > >  
> > >  		err = register_netdevice(tun->dev);
> > >  		if (err < 0)
> > > -			goto err_free_dev;
> > > +			goto err_detach;
> > >  
> > >  		if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
> > >  		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
> > > @@ -1689,6 +1689,11 @@ static int tun_set_iff(struct net *net, struct file
> > > *file, struct ifreq *ifr)
> > >  	strcpy(ifr->ifr_name, tun->dev->name);
> > >  	return 0;
> > >  
> > > +err_detach:
> > > +	tun_detach_all(dev);
> > > +err_free_flow:
> > > +	tun_flow_uninit(tun);
> > > +	security_tun_dev_free_security(tun->security);
> > 
> > This bit looks wrong: if flow_init fails, we
> > need security_tun_dev_free_security, don't we?
> > I think we need:
> > 	+err_free_sec:	security_tun_dev_free_security(tun->security);
> > and goto here on flow_init failures.
> 
> tun_flow_init() always succeed. So we're ok here.

True. So please make it return void then.

> > 
> > >   err_free_dev:
> > 
> > Pls shift this one 1 space left for consistency.
> > 
> 
> Ok.
> > >  	free_netdev(dev);
> > >  	return err;
> > > --
> > > 1.7.1
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at  http://www.tux.org/lkml/
> > 
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Jason Wang Sept. 11, 2013, 10:18 a.m. UTC | #4
----- Original Message -----
> On Wed, Sep 11, 2013 at 05:55:04AM -0400, Jason Wang wrote:
> > 
> > 
> > ----- Original Message -----
> > > On Wed, Sep 11, 2013 at 04:24:05PM +0800, Jason Wang wrote:
> > > > Commit c8d68e6be1c3b242f1c598595830890b65cea64a (tuntap: multiqueue
> > > > support)
> > > > only call free_netdev() on err in tun_set_iff(). This causes several
> > > > issues:
> > > > 
> > > > - memory of tun security were leaked
> > > 
> > > Not just tun security -  sock reference too (didn't detach)
> > > 
> > 
> > Yes, I mention it in the next item.
> 
> That line's a bit too long btw.
> Keep it under 70 chars for commit logs.
> 

Ok.
> > > > - use after free since the flow gc timer was not deleted and the tfile
> > > > were
> > > > not
> > > >   detached
> > > > 
> > > > This patch solves the above issues.
> > > > 
> > > > Reported-by: Wannes Rombouts <wannes.rombouts@epitech.eu>
> > > > Cc: Michael S. Tsirkin <mst@redhat.com>
> > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > > ---
> > > > The patch were also needed for stable 3.8+.
> > > > ---
> > > >  drivers/net/tun.c |    9 +++++++--
> > > >  1 files changed, 7 insertions(+), 2 deletions(-)
> > > > 
> > > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > > > index a639de8..e5fb5d3 100644
> > > > --- a/drivers/net/tun.c
> > > > +++ b/drivers/net/tun.c
> > > > @@ -1641,11 +1641,11 @@ static int tun_set_iff(struct net *net, struct
> > > > file
> > > > *file, struct ifreq *ifr)
> > > >  		INIT_LIST_HEAD(&tun->disabled);
> > > >  		err = tun_attach(tun, file, false);
> > > >  		if (err < 0)
> > > > -			goto err_free_dev;
> > > > +			goto err_free_flow;
> > > >  
> > > >  		err = register_netdevice(tun->dev);
> > > >  		if (err < 0)
> > > > -			goto err_free_dev;
> > > > +			goto err_detach;
> > > >  
> > > >  		if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
> > > >  		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
> > > > @@ -1689,6 +1689,11 @@ static int tun_set_iff(struct net *net, struct
> > > > file
> > > > *file, struct ifreq *ifr)
> > > >  	strcpy(ifr->ifr_name, tun->dev->name);
> > > >  	return 0;
> > > >  
> > > > +err_detach:
> > > > +	tun_detach_all(dev);
> > > > +err_free_flow:
> > > > +	tun_flow_uninit(tun);
> > > > +	security_tun_dev_free_security(tun->security);
> > > 
> > > This bit looks wrong: if flow_init fails, we
> > > need security_tun_dev_free_security, don't we?
> > > I think we need:
> > > 	+err_free_sec:	security_tun_dev_free_security(tun->security);
> > > and goto here on flow_init failures.
> > 
> > tun_flow_init() always succeed. So we're ok here.
> 
> True. So please make it return void then.
> 

It has already returned void.
> > > 
> > > >   err_free_dev:
> > > 
> > > Pls shift this one 1 space left for consistency.
> > > 
> > 
> > Ok.
> > > >  	free_netdev(dev);
> > > >  	return err;
> > > > --
> > > > 1.7.1
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-kernel"
> > > in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > > Please read the FAQ at  http://www.tux.org/lkml/
> > > 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
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> Please read the FAQ at  http://www.tux.org/lkml/
> 
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Michael S. Tsirkin Sept. 11, 2013, 10:58 a.m. UTC | #5
On Wed, Sep 11, 2013 at 01:08:04PM +0300, Michael S. Tsirkin wrote:
> On Wed, Sep 11, 2013 at 05:55:04AM -0400, Jason Wang wrote:
> > 
> > 
> > ----- Original Message -----
> > > On Wed, Sep 11, 2013 at 04:24:05PM +0800, Jason Wang wrote:
> > > > Commit c8d68e6be1c3b242f1c598595830890b65cea64a (tuntap: multiqueue
> > > > support)
> > > > only call free_netdev() on err in tun_set_iff(). This causes several
> > > > issues:
> > > > 
> > > > - memory of tun security were leaked
> > > 
> > > Not just tun security -  sock reference too (didn't detach)
> > > 
> > 
> > Yes, I mention it in the next item.
> 
> That line's a bit too long btw.
> Keep it under 70 chars for commit logs.
> 
> > > > - use after free since the flow gc timer was not deleted and the tfile were
> > > > not
> > > >   detached
> > > > 
> > > > This patch solves the above issues.
> > > > 
> > > > Reported-by: Wannes Rombouts <wannes.rombouts@epitech.eu>
> > > > Cc: Michael S. Tsirkin <mst@redhat.com>
> > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > > ---
> > > > The patch were also needed for stable 3.8+.
> > > > ---
> > > >  drivers/net/tun.c |    9 +++++++--
> > > >  1 files changed, 7 insertions(+), 2 deletions(-)
> > > > 
> > > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > > > index a639de8..e5fb5d3 100644
> > > > --- a/drivers/net/tun.c
> > > > +++ b/drivers/net/tun.c
> > > > @@ -1641,11 +1641,11 @@ static int tun_set_iff(struct net *net, struct file
> > > > *file, struct ifreq *ifr)
> > > >  		INIT_LIST_HEAD(&tun->disabled);
> > > >  		err = tun_attach(tun, file, false);
> > > >  		if (err < 0)
> > > > -			goto err_free_dev;
> > > > +			goto err_free_flow;
> > > >  
> > > >  		err = register_netdevice(tun->dev);
> > > >  		if (err < 0)
> > > > -			goto err_free_dev;
> > > > +			goto err_detach;
> > > >  
> > > >  		if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
> > > >  		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
> > > > @@ -1689,6 +1689,11 @@ static int tun_set_iff(struct net *net, struct file
> > > > *file, struct ifreq *ifr)
> > > >  	strcpy(ifr->ifr_name, tun->dev->name);
> > > >  	return 0;
> > > >  
> > > > +err_detach:
> > > > +	tun_detach_all(dev);
> > > > +err_free_flow:
> > > > +	tun_flow_uninit(tun);
> > > > +	security_tun_dev_free_security(tun->security);
> > > 
> > > This bit looks wrong: if flow_init fails, we
> > > need security_tun_dev_free_security, don't we?
> > > I think we need:
> > > 	+err_free_sec:	security_tun_dev_free_security(tun->security);
> > > and goto here on flow_init failures.
> > 
> > tun_flow_init() always succeed. So we're ok here.
> 
> True. So please make it return void then.

Heh I was looking at a stale tree, this is already fixed
in commit 944a1376b.

> > > 
> > > >   err_free_dev:
> > > 
> > > Pls shift this one 1 space left for consistency.
> > > 
> > 
> > Ok.
> > > >  	free_netdev(dev);
> > > >  	return err;
> > > > --
> > > > 1.7.1
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > > Please read the FAQ at  http://www.tux.org/lkml/
> > > 
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diff mbox

Patch

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a639de8..e5fb5d3 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1641,11 +1641,11 @@  static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		INIT_LIST_HEAD(&tun->disabled);
 		err = tun_attach(tun, file, false);
 		if (err < 0)
-			goto err_free_dev;
+			goto err_free_flow;
 
 		err = register_netdevice(tun->dev);
 		if (err < 0)
-			goto err_free_dev;
+			goto err_detach;
 
 		if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
 		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
@@ -1689,6 +1689,11 @@  static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 	strcpy(ifr->ifr_name, tun->dev->name);
 	return 0;
 
+err_detach:
+	tun_detach_all(dev);
+err_free_flow:
+	tun_flow_uninit(tun);
+	security_tun_dev_free_security(tun->security);
  err_free_dev:
 	free_netdev(dev);
 	return err;