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* [patch] tun: signedness bug in tun_get_user()
@ 2013-08-15 12:52 ` Dan Carpenter
  0 siblings, 0 replies; 14+ messages in thread
From: Dan Carpenter @ 2013-08-15 12:52 UTC (permalink / raw)
  To: David S. Miller
  Cc: Jason Wang, Michael S. Tsirkin, Eric Dumazet, Neil Horman,
	netdev, kernel-janitors

The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
not totally correct.  Because "len" and "sizeof()" are size_t type, that
means they are never less than zero.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index af987f0..7ed13cc 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	u32 rxhash;
 
 	if (!(tun->flags & TUN_NO_PI)) {
-		if ((len -= sizeof(pi)) < 0)
+		if (len < sizeof(pi))
 			return -EINVAL;
+		len -= sizeof(pi);
 
 		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
 			return -EFAULT;
@@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	}
 
 	if (tun->flags & TUN_VNET_HDR) {
-		if ((len -= tun->vnet_hdr_sz) < 0)
+		if (len < tun->vnet_hdr_sz)
 			return -EINVAL;
+		len -= tun->vnet_hdr_sz;
 
 		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
 			return -EFAULT;

^ permalink raw reply related	[flat|nested] 14+ messages in thread

* [patch] tun: signedness bug in tun_get_user()
@ 2013-08-15 12:52 ` Dan Carpenter
  0 siblings, 0 replies; 14+ messages in thread
From: Dan Carpenter @ 2013-08-15 12:52 UTC (permalink / raw)
  To: David S. Miller
  Cc: Jason Wang, Michael S. Tsirkin, Eric Dumazet, Neil Horman,
	netdev, kernel-janitors

The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
not totally correct.  Because "len" and "sizeof()" are size_t type, that
means they are never less than zero.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index af987f0..7ed13cc 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	u32 rxhash;
 
 	if (!(tun->flags & TUN_NO_PI)) {
-		if ((len -= sizeof(pi)) < 0)
+		if (len < sizeof(pi))
 			return -EINVAL;
+		len -= sizeof(pi);
 
 		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
 			return -EFAULT;
@@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	}
 
 	if (tun->flags & TUN_VNET_HDR) {
-		if ((len -= tun->vnet_hdr_sz) < 0)
+		if (len < tun->vnet_hdr_sz)
 			return -EINVAL;
+		len -= tun->vnet_hdr_sz;
 
 		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
 			return -EFAULT;

^ permalink raw reply related	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
  2013-08-15 12:52 ` Dan Carpenter
@ 2013-08-15 14:04   ` Michael S. Tsirkin
  -1 siblings, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2013-08-15 14:04 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Eric Dumazet, Neil Horman, netdev,
	kernel-janitors

On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> not totally correct.  Because "len" and "sizeof()" are size_t type, that
> means they are never less than zero.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index af987f0..7ed13cc 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
>  	u32 rxhash;
>  
>  	if (!(tun->flags & TUN_NO_PI)) {
> -		if ((len -= sizeof(pi)) < 0)
> +		if (len < sizeof(pi))
>  			return -EINVAL;
> +		len -= sizeof(pi);
>  
>  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
>  			return -EFAULT;
> @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
>  	}
>  
>  	if (tun->flags & TUN_VNET_HDR) {
> -		if ((len -= tun->vnet_hdr_sz) < 0)
> +		if (len < tun->vnet_hdr_sz)
>  			return -EINVAL;
> +		len -= tun->vnet_hdr_sz;
>  
>  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
>  			return -EFAULT;

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
@ 2013-08-15 14:04   ` Michael S. Tsirkin
  0 siblings, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2013-08-15 14:04 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Eric Dumazet, Neil Horman, netdev,
	kernel-janitors

On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> not totally correct.  Because "len" and "sizeof()" are size_t type, that
> means they are never less than zero.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index af987f0..7ed13cc 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
>  	u32 rxhash;
>  
>  	if (!(tun->flags & TUN_NO_PI)) {
> -		if ((len -= sizeof(pi)) < 0)
> +		if (len < sizeof(pi))
>  			return -EINVAL;
> +		len -= sizeof(pi);
>  
>  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
>  			return -EFAULT;
> @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
>  	}
>  
>  	if (tun->flags & TUN_VNET_HDR) {
> -		if ((len -= tun->vnet_hdr_sz) < 0)
> +		if (len < tun->vnet_hdr_sz)
>  			return -EINVAL;
> +		len -= tun->vnet_hdr_sz;
>  
>  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
>  			return -EFAULT;

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
  2013-08-15 14:04   ` Michael S. Tsirkin
@ 2013-08-15 14:58     ` Michael S. Tsirkin
  -1 siblings, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2013-08-15 14:58 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Eric Dumazet, Neil Horman, netdev,
	kernel-janitors

On Thu, Aug 15, 2013 at 05:04:49PM +0300, Michael S. Tsirkin wrote:
> On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> > The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> > not totally correct.  Because "len" and "sizeof()" are size_t type, that
> > means they are never less than zero.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>

Alternatively how about we revert the original patch?
This is not the only issue it introduced and it doesn't
actually fix any bugs.

> > 
> > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > index af987f0..7ed13cc 100644
> > --- a/drivers/net/tun.c
> > +++ b/drivers/net/tun.c
> > @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> >  	u32 rxhash;
> >  
> >  	if (!(tun->flags & TUN_NO_PI)) {
> > -		if ((len -= sizeof(pi)) < 0)
> > +		if (len < sizeof(pi))
> >  			return -EINVAL;
> > +		len -= sizeof(pi);
> >  
> >  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
> >  			return -EFAULT;
> > @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> >  	}
> >  
> >  	if (tun->flags & TUN_VNET_HDR) {
> > -		if ((len -= tun->vnet_hdr_sz) < 0)
> > +		if (len < tun->vnet_hdr_sz)
> >  			return -EINVAL;
> > +		len -= tun->vnet_hdr_sz;
> >  
> >  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
> >  			return -EFAULT;

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
@ 2013-08-15 14:58     ` Michael S. Tsirkin
  0 siblings, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2013-08-15 14:58 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Eric Dumazet, Neil Horman, netdev,
	kernel-janitors

On Thu, Aug 15, 2013 at 05:04:49PM +0300, Michael S. Tsirkin wrote:
> On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> > The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> > not totally correct.  Because "len" and "sizeof()" are size_t type, that
> > means they are never less than zero.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>

Alternatively how about we revert the original patch?
This is not the only issue it introduced and it doesn't
actually fix any bugs.

> > 
> > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > index af987f0..7ed13cc 100644
> > --- a/drivers/net/tun.c
> > +++ b/drivers/net/tun.c
> > @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> >  	u32 rxhash;
> >  
> >  	if (!(tun->flags & TUN_NO_PI)) {
> > -		if ((len -= sizeof(pi)) < 0)
> > +		if (len < sizeof(pi))
> >  			return -EINVAL;
> > +		len -= sizeof(pi);
> >  
> >  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
> >  			return -EFAULT;
> > @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> >  	}
> >  
> >  	if (tun->flags & TUN_VNET_HDR) {
> > -		if ((len -= tun->vnet_hdr_sz) < 0)
> > +		if (len < tun->vnet_hdr_sz)
> >  			return -EINVAL;
> > +		len -= tun->vnet_hdr_sz;
> >  
> >  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
> >  			return -EFAULT;

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
  2013-08-15 14:58     ` Michael S. Tsirkin
@ 2013-08-15 15:02       ` Michael S. Tsirkin
  -1 siblings, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2013-08-15 15:02 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Eric Dumazet, Neil Horman, netdev,
	kernel-janitors

On Thu, Aug 15, 2013 at 05:58:40PM +0300, Michael S. Tsirkin wrote:
> On Thu, Aug 15, 2013 at 05:04:49PM +0300, Michael S. Tsirkin wrote:
> > On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> > > The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> > > not totally correct.  Because "len" and "sizeof()" are size_t type, that
> > > means they are never less than zero.
> > > 
> > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> Alternatively how about we revert the original patch?
> This is not the only issue it introduced and it doesn't
> actually fix any bugs.
> 
> > > 
> > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > > index af987f0..7ed13cc 100644
> > > --- a/drivers/net/tun.c
> > > +++ b/drivers/net/tun.c
> > > @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> > >  	u32 rxhash;
> > >  
> > >  	if (!(tun->flags & TUN_NO_PI)) {
> > > -		if ((len -= sizeof(pi)) < 0)
> > > +		if (len < sizeof(pi))
> > >  			return -EINVAL;
> > > +		len -= sizeof(pi);
> > >  
> > >  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
> > >  			return -EFAULT;
> > > @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> > >  	}
> > >  
> > >  	if (tun->flags & TUN_VNET_HDR) {
> > > -		if ((len -= tun->vnet_hdr_sz) < 0)
> > > +		if (len < tun->vnet_hdr_sz)
> > >  			return -EINVAL;

And to be even more explicit, this still doesn't handle the
case vnet_hdr_sz < 0 properly.


> > > +		len -= tun->vnet_hdr_sz;
> > >  
> > >  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
> > >  			return -EFAULT;

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
@ 2013-08-15 15:02       ` Michael S. Tsirkin
  0 siblings, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2013-08-15 15:02 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Eric Dumazet, Neil Horman, netdev,
	kernel-janitors

On Thu, Aug 15, 2013 at 05:58:40PM +0300, Michael S. Tsirkin wrote:
> On Thu, Aug 15, 2013 at 05:04:49PM +0300, Michael S. Tsirkin wrote:
> > On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> > > The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> > > not totally correct.  Because "len" and "sizeof()" are size_t type, that
> > > means they are never less than zero.
> > > 
> > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> Alternatively how about we revert the original patch?
> This is not the only issue it introduced and it doesn't
> actually fix any bugs.
> 
> > > 
> > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > > index af987f0..7ed13cc 100644
> > > --- a/drivers/net/tun.c
> > > +++ b/drivers/net/tun.c
> > > @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> > >  	u32 rxhash;
> > >  
> > >  	if (!(tun->flags & TUN_NO_PI)) {
> > > -		if ((len -= sizeof(pi)) < 0)
> > > +		if (len < sizeof(pi))
> > >  			return -EINVAL;
> > > +		len -= sizeof(pi);
> > >  
> > >  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
> > >  			return -EFAULT;
> > > @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> > >  	}
> > >  
> > >  	if (tun->flags & TUN_VNET_HDR) {
> > > -		if ((len -= tun->vnet_hdr_sz) < 0)
> > > +		if (len < tun->vnet_hdr_sz)
> > >  			return -EINVAL;

And to be even more explicit, this still doesn't handle the
case vnet_hdr_sz < 0 properly.


> > > +		len -= tun->vnet_hdr_sz;
> > >  
> > >  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
> > >  			return -EFAULT;

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
  2013-08-15 15:02       ` Michael S. Tsirkin
@ 2013-08-15 15:05         ` Michael S. Tsirkin
  -1 siblings, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2013-08-15 15:05 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Eric Dumazet, Neil Horman, netdev,
	kernel-janitors

On Thu, Aug 15, 2013 at 06:02:14PM +0300, Michael S. Tsirkin wrote:
> On Thu, Aug 15, 2013 at 05:58:40PM +0300, Michael S. Tsirkin wrote:
> > On Thu, Aug 15, 2013 at 05:04:49PM +0300, Michael S. Tsirkin wrote:
> > > On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> > > > The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> > > > not totally correct.  Because "len" and "sizeof()" are size_t type, that
> > > > means they are never less than zero.
> > > > 
> > > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > 
> > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > 
> > Alternatively how about we revert the original patch?
> > This is not the only issue it introduced and it doesn't
> > actually fix any bugs.
> > 
> > > > 
> > > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > > > index af987f0..7ed13cc 100644
> > > > --- a/drivers/net/tun.c
> > > > +++ b/drivers/net/tun.c
> > > > @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> > > >  	u32 rxhash;
> > > >  
> > > >  	if (!(tun->flags & TUN_NO_PI)) {
> > > > -		if ((len -= sizeof(pi)) < 0)
> > > > +		if (len < sizeof(pi))
> > > >  			return -EINVAL;
> > > > +		len -= sizeof(pi);
> > > >  
> > > >  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
> > > >  			return -EFAULT;
> > > > @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> > > >  	}
> > > >  
> > > >  	if (tun->flags & TUN_VNET_HDR) {
> > > > -		if ((len -= tun->vnet_hdr_sz) < 0)
> > > > +		if (len < tun->vnet_hdr_sz)
> > > >  			return -EINVAL;
> 
> And to be even more explicit, this still doesn't handle the
> case vnet_hdr_sz < 0 properly.

Hmm ENOCOFFEE.
User can't make vnet_hdr_sz < 0 - we already catch that.
So let's apply Dan's patch, it does fix all issues after all.
Sorry about the noise.

> 
> > > > +		len -= tun->vnet_hdr_sz;
> > > >  
> > > >  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
> > > >  			return -EFAULT;

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
@ 2013-08-15 15:05         ` Michael S. Tsirkin
  0 siblings, 0 replies; 14+ messages in thread
From: Michael S. Tsirkin @ 2013-08-15 15:05 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Eric Dumazet, Neil Horman, netdev,
	kernel-janitors

On Thu, Aug 15, 2013 at 06:02:14PM +0300, Michael S. Tsirkin wrote:
> On Thu, Aug 15, 2013 at 05:58:40PM +0300, Michael S. Tsirkin wrote:
> > On Thu, Aug 15, 2013 at 05:04:49PM +0300, Michael S. Tsirkin wrote:
> > > On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> > > > The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> > > > not totally correct.  Because "len" and "sizeof()" are size_t type, that
> > > > means they are never less than zero.
> > > > 
> > > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > 
> > > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > 
> > Alternatively how about we revert the original patch?
> > This is not the only issue it introduced and it doesn't
> > actually fix any bugs.
> > 
> > > > 
> > > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> > > > index af987f0..7ed13cc 100644
> > > > --- a/drivers/net/tun.c
> > > > +++ b/drivers/net/tun.c
> > > > @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> > > >  	u32 rxhash;
> > > >  
> > > >  	if (!(tun->flags & TUN_NO_PI)) {
> > > > -		if ((len -= sizeof(pi)) < 0)
> > > > +		if (len < sizeof(pi))
> > > >  			return -EINVAL;
> > > > +		len -= sizeof(pi);
> > > >  
> > > >  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
> > > >  			return -EFAULT;
> > > > @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
> > > >  	}
> > > >  
> > > >  	if (tun->flags & TUN_VNET_HDR) {
> > > > -		if ((len -= tun->vnet_hdr_sz) < 0)
> > > > +		if (len < tun->vnet_hdr_sz)
> > > >  			return -EINVAL;
> 
> And to be even more explicit, this still doesn't handle the
> case vnet_hdr_sz < 0 properly.

Hmm ENOCOFFEE.
User can't make vnet_hdr_sz < 0 - we already catch that.
So let's apply Dan's patch, it does fix all issues after all.
Sorry about the noise.

> 
> > > > +		len -= tun->vnet_hdr_sz;
> > > >  
> > > >  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
> > > >  			return -EFAULT;

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
  2013-08-15 12:52 ` Dan Carpenter
@ 2013-08-15 20:08   ` Neil Horman
  -1 siblings, 0 replies; 14+ messages in thread
From: Neil Horman @ 2013-08-15 20:08 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Michael S. Tsirkin, Eric Dumazet,
	netdev, kernel-janitors

On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> not totally correct.  Because "len" and "sizeof()" are size_t type, that
> means they are never less than zero.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index af987f0..7ed13cc 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
>  	u32 rxhash;
>  
>  	if (!(tun->flags & TUN_NO_PI)) {
> -		if ((len -= sizeof(pi)) < 0)
> +		if (len < sizeof(pi))
>  			return -EINVAL;
> +		len -= sizeof(pi);
>  
>  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
>  			return -EFAULT;
> @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
>  	}
>  
>  	if (tun->flags & TUN_VNET_HDR) {
> -		if ((len -= tun->vnet_hdr_sz) < 0)
> +		if (len < tun->vnet_hdr_sz)
>  			return -EINVAL;
> +		len -= tun->vnet_hdr_sz;
>  
>  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
>  			return -EFAULT;
> 

Acked-by: Neil Horman <nhorman@tuxdriver.com>

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
@ 2013-08-15 20:08   ` Neil Horman
  0 siblings, 0 replies; 14+ messages in thread
From: Neil Horman @ 2013-08-15 20:08 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: David S. Miller, Jason Wang, Michael S. Tsirkin, Eric Dumazet,
	netdev, kernel-janitors

On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
> The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
> not totally correct.  Because "len" and "sizeof()" are size_t type, that
> means they are never less than zero.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index af987f0..7ed13cc 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -977,8 +977,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
>  	u32 rxhash;
>  
>  	if (!(tun->flags & TUN_NO_PI)) {
> -		if ((len -= sizeof(pi)) < 0)
> +		if (len < sizeof(pi))
>  			return -EINVAL;
> +		len -= sizeof(pi);
>  
>  		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
>  			return -EFAULT;
> @@ -986,8 +987,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
>  	}
>  
>  	if (tun->flags & TUN_VNET_HDR) {
> -		if ((len -= tun->vnet_hdr_sz) < 0)
> +		if (len < tun->vnet_hdr_sz)
>  			return -EINVAL;
> +		len -= tun->vnet_hdr_sz;
>  
>  		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
>  			return -EFAULT;
> 

Acked-by: Neil Horman <nhorman@tuxdriver.com>

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
  2013-08-15 20:08   ` Neil Horman
@ 2013-08-15 21:51     ` David Miller
  -1 siblings, 0 replies; 14+ messages in thread
From: David Miller @ 2013-08-15 21:51 UTC (permalink / raw)
  To: nhorman; +Cc: dan.carpenter, jasowang, mst, edumazet, netdev, kernel-janitors

From: Neil Horman <nhorman@tuxdriver.com>
Date: Thu, 15 Aug 2013 16:08:35 -0400

> On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
>> The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
>> not totally correct.  Because "len" and "sizeof()" are size_t type, that
>> means they are never less than zero.
>> 
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
 ...
> Acked-by: Neil Horman <nhorman@tuxdriver.com>

Applied, thanks everyone.

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [patch] tun: signedness bug in tun_get_user()
@ 2013-08-15 21:51     ` David Miller
  0 siblings, 0 replies; 14+ messages in thread
From: David Miller @ 2013-08-15 21:51 UTC (permalink / raw)
  To: nhorman; +Cc: dan.carpenter, jasowang, mst, edumazet, netdev, kernel-janitors

From: Neil Horman <nhorman@tuxdriver.com>
Date: Thu, 15 Aug 2013 16:08:35 -0400

> On Thu, Aug 15, 2013 at 03:52:57PM +0300, Dan Carpenter wrote:
>> The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
>> not totally correct.  Because "len" and "sizeof()" are size_t type, that
>> means they are never less than zero.
>> 
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
 ...
> Acked-by: Neil Horman <nhorman@tuxdriver.com>

Applied, thanks everyone.

^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2013-08-15 21:51 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-08-15 12:52 [patch] tun: signedness bug in tun_get_user() Dan Carpenter
2013-08-15 12:52 ` Dan Carpenter
2013-08-15 14:04 ` Michael S. Tsirkin
2013-08-15 14:04   ` Michael S. Tsirkin
2013-08-15 14:58   ` Michael S. Tsirkin
2013-08-15 14:58     ` Michael S. Tsirkin
2013-08-15 15:02     ` Michael S. Tsirkin
2013-08-15 15:02       ` Michael S. Tsirkin
2013-08-15 15:05       ` Michael S. Tsirkin
2013-08-15 15:05         ` Michael S. Tsirkin
2013-08-15 20:08 ` Neil Horman
2013-08-15 20:08   ` Neil Horman
2013-08-15 21:51   ` David Miller
2013-08-15 21:51     ` David Miller

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