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* [patch 2/2 v2] staging: lustre: integer overflow in obd_ioctl_is_invalid()
       [not found] <20140425072317.GD4963@mwanda>
@ 2014-04-28 10:58 ` Dan Carpenter
  2014-04-28 11:35   ` walter harms
  0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2014-04-28 10:58 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: Peng Tao, Andreas Dilger, Oleg Drokin, John L. Hammond,
	Dmitry Eremin, Jinshan Xiong, Dulshani Gunawardhana, devel,
	linux-kernel, kernel-janitors, walter harms

The obd_ioctl_getdata() function caps "data->ioc_len" at
OBD_MAX_IOCTL_BUFFER and then calls this obd_ioctl_is_invalid() to check
that the other values inside data are valid.

There are several lengths inside data but when they are added together
they must not be larger than "data->ioc_len".  The checks against
"(data->ioc_inllen1 > (1<<30))" are supposed to ensure that the addition
does not have an integer overflow.  But "(1<<30) * 4" actually can
overflow 32 bits, so the checks are insufficient.

I have changed it to "> OBD_MAX_IOCTL_BUFFER" instead.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: Updated the error messages as Walter Harms pointed out.

diff --git a/drivers/staging/lustre/lustre/include/lustre_lib.h b/drivers/staging/lustre/lustre/include/lustre_lib.h
index bdc9812..3c26bbd 100644
--- a/drivers/staging/lustre/lustre/include/lustre_lib.h
+++ b/drivers/staging/lustre/lustre/include/lustre_lib.h
@@ -179,24 +179,25 @@ static inline int obd_ioctl_packlen(struct obd_ioctl_data *data)
 
 static inline int obd_ioctl_is_invalid(struct obd_ioctl_data *data)
 {
-	if (data->ioc_len > (1<<30)) {
-		CERROR("OBD ioctl: ioc_len larger than 1<<30\n");
+	if (data->ioc_len > OBD_MAX_IOCTL_BUFFER) {
+		CERROR("OBD ioctl: ioc_len larger than %d\n",
+		       OBD_MAX_IOCTL_BUFFER);
 		return 1;
 	}
-	if (data->ioc_inllen1 > (1<<30)) {
-		CERROR("OBD ioctl: ioc_inllen1 larger than 1<<30\n");
+	if (data->ioc_inllen1 > OBD_MAX_IOCTL_BUFFER) {
+		CERROR("OBD ioctl: ioc_inllen1 larger than ioc_len\n");
 		return 1;
 	}
-	if (data->ioc_inllen2 > (1<<30)) {
-		CERROR("OBD ioctl: ioc_inllen2 larger than 1<<30\n");
+	if (data->ioc_inllen2 > OBD_MAX_IOCTL_BUFFER) {
+		CERROR("OBD ioctl: ioc_inllen2 larger than ioc_len\n");
 		return 1;
 	}
-	if (data->ioc_inllen3 > (1<<30)) {
-		CERROR("OBD ioctl: ioc_inllen3 larger than 1<<30\n");
+	if (data->ioc_inllen3 > OBD_MAX_IOCTL_BUFFER) {
+		CERROR("OBD ioctl: ioc_inllen3 larger than ioc_len\n");
 		return 1;
 	}
-	if (data->ioc_inllen4 > (1<<30)) {
-		CERROR("OBD ioctl: ioc_inllen4 larger than 1<<30\n");
+	if (data->ioc_inllen4 > OBD_MAX_IOCTL_BUFFER) {
+		CERROR("OBD ioctl: ioc_inllen4 larger than ioc_len\n");
 		return 1;
 	}
 	if (data->ioc_inlbuf1 && !data->ioc_inllen1) {

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

* Re: [patch 2/2 v2] staging: lustre: integer overflow in obd_ioctl_is_invalid()
  2014-04-28 10:58 ` [patch 2/2 v2] staging: lustre: integer overflow in obd_ioctl_is_invalid() Dan Carpenter
@ 2014-04-28 11:35   ` walter harms
  2014-04-28 11:41     ` Dan Carpenter
  0 siblings, 1 reply; 3+ messages in thread
From: walter harms @ 2014-04-28 11:35 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: Greg Kroah-Hartman, Peng Tao, Andreas Dilger, Oleg Drokin,
	John L. Hammond, Dmitry Eremin, Jinshan Xiong,
	Dulshani Gunawardhana, devel, linux-kernel, kernel-janitors



Am 28.04.2014 12:58, schrieb Dan Carpenter:
> The obd_ioctl_getdata() function caps "data->ioc_len" at
> OBD_MAX_IOCTL_BUFFER and then calls this obd_ioctl_is_invalid() to check
> that the other values inside data are valid.
> 
> There are several lengths inside data but when they are added together
> they must not be larger than "data->ioc_len".  The checks against
> "(data->ioc_inllen1 > (1<<30))" are supposed to ensure that the addition
> does not have an integer overflow.  But "(1<<30) * 4" actually can
> overflow 32 bits, so the checks are insufficient.
> 
> I have changed it to "> OBD_MAX_IOCTL_BUFFER" instead.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> v2: Updated the error messages as Walter Harms pointed out.
> 
> diff --git a/drivers/staging/lustre/lustre/include/lustre_lib.h b/drivers/staging/lustre/lustre/include/lustre_lib.h
> index bdc9812..3c26bbd 100644
> --- a/drivers/staging/lustre/lustre/include/lustre_lib.h
> +++ b/drivers/staging/lustre/lustre/include/lustre_lib.h
> @@ -179,24 +179,25 @@ static inline int obd_ioctl_packlen(struct obd_ioctl_data *data)
>  
>  static inline int obd_ioctl_is_invalid(struct obd_ioctl_data *data)
>  {
> -	if (data->ioc_len > (1<<30)) {
> -		CERROR("OBD ioctl: ioc_len larger than 1<<30\n");
> +	if (data->ioc_len > OBD_MAX_IOCTL_BUFFER) {
> +		CERROR("OBD ioctl: ioc_len larger than %d\n",
> +		       OBD_MAX_IOCTL_BUFFER);
>  		return 1;
>  	}
> -	if (data->ioc_inllen1 > (1<<30)) {
> -		CERROR("OBD ioctl: ioc_inllen1 larger than 1<<30\n");
> +	if (data->ioc_inllen1 > OBD_MAX_IOCTL_BUFFER) {
> +		CERROR("OBD ioctl: ioc_inllen1 larger than ioc_len\n");
>  		return 1;
>  	}

The error mention ioc_len the compare is OBD_MAX_IOCTL_BUFFER ?
Is that intentional ?

re,
 wh

> -	if (data->ioc_inllen2 > (1<<30)) {
> -		CERROR("OBD ioctl: ioc_inllen2 larger than 1<<30\n");
> +	if (data->ioc_inllen2 > OBD_MAX_IOCTL_BUFFER) {
> +		CERROR("OBD ioctl: ioc_inllen2 larger than ioc_len\n");
>  		return 1;
>  	}
> -	if (data->ioc_inllen3 > (1<<30)) {
> -		CERROR("OBD ioctl: ioc_inllen3 larger than 1<<30\n");
> +	if (data->ioc_inllen3 > OBD_MAX_IOCTL_BUFFER) {
> +		CERROR("OBD ioctl: ioc_inllen3 larger than ioc_len\n");
>  		return 1;
>  	}
> -	if (data->ioc_inllen4 > (1<<30)) {
> -		CERROR("OBD ioctl: ioc_inllen4 larger than 1<<30\n");
> +	if (data->ioc_inllen4 > OBD_MAX_IOCTL_BUFFER) {
> +		CERROR("OBD ioctl: ioc_inllen4 larger than ioc_len\n");
>  		return 1;
>  	}
>  	if (data->ioc_inlbuf1 && !data->ioc_inllen1) {
> 

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

* Re: [patch 2/2 v2] staging: lustre: integer overflow in obd_ioctl_is_invalid()
  2014-04-28 11:35   ` walter harms
@ 2014-04-28 11:41     ` Dan Carpenter
  0 siblings, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2014-04-28 11:41 UTC (permalink / raw)
  To: walter harms
  Cc: Greg Kroah-Hartman, Peng Tao, Andreas Dilger, Oleg Drokin,
	John L. Hammond, Dmitry Eremin, Jinshan Xiong,
	Dulshani Gunawardhana, devel, linux-kernel, kernel-janitors

On Mon, Apr 28, 2014 at 01:35:19PM +0200, walter harms wrote:
> 
> 
> Am 28.04.2014 12:58, schrieb Dan Carpenter:
> > The obd_ioctl_getdata() function caps "data->ioc_len" at
> > OBD_MAX_IOCTL_BUFFER and then calls this obd_ioctl_is_invalid() to check
> > that the other values inside data are valid.
> > 
> > There are several lengths inside data but when they are added together
> > they must not be larger than "data->ioc_len".  The checks against
> > "(data->ioc_inllen1 > (1<<30))" are supposed to ensure that the addition
> > does not have an integer overflow.  But "(1<<30) * 4" actually can
> > overflow 32 bits, so the checks are insufficient.
> > 
> > I have changed it to "> OBD_MAX_IOCTL_BUFFER" instead.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > v2: Updated the error messages as Walter Harms pointed out.
> > 
> > diff --git a/drivers/staging/lustre/lustre/include/lustre_lib.h b/drivers/staging/lustre/lustre/include/lustre_lib.h
> > index bdc9812..3c26bbd 100644
> > --- a/drivers/staging/lustre/lustre/include/lustre_lib.h
> > +++ b/drivers/staging/lustre/lustre/include/lustre_lib.h
> > @@ -179,24 +179,25 @@ static inline int obd_ioctl_packlen(struct obd_ioctl_data *data)
> >  
> >  static inline int obd_ioctl_is_invalid(struct obd_ioctl_data *data)
> >  {
> > -	if (data->ioc_len > (1<<30)) {
> > -		CERROR("OBD ioctl: ioc_len larger than 1<<30\n");
> > +	if (data->ioc_len > OBD_MAX_IOCTL_BUFFER) {
> > +		CERROR("OBD ioctl: ioc_len larger than %d\n",
> > +		       OBD_MAX_IOCTL_BUFFER);
> >  		return 1;
> >  	}
> > -	if (data->ioc_inllen1 > (1<<30)) {
> > -		CERROR("OBD ioctl: ioc_inllen1 larger than 1<<30\n");
> > +	if (data->ioc_inllen1 > OBD_MAX_IOCTL_BUFFER) {
> > +		CERROR("OBD ioctl: ioc_inllen1 larger than ioc_len\n");
> >  		return 1;
> >  	}
> 
> The error mention ioc_len the compare is OBD_MAX_IOCTL_BUFFER ?
> Is that intentional ?

Yep.

regards,
dan carpenter


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

end of thread, other threads:[~2014-04-28 11:41 UTC | newest]

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     [not found] <20140425072317.GD4963@mwanda>
2014-04-28 10:58 ` [patch 2/2 v2] staging: lustre: integer overflow in obd_ioctl_is_invalid() Dan Carpenter
2014-04-28 11:35   ` walter harms
2014-04-28 11:41     ` Dan Carpenter

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