[PATCH] macintosh:fix oob read in do_adb_query function

[PATCH] macintosh:fix oob read in do_adb_query function

[NAME]

From: sohu0106 <sohu0106@126.com>

In do_adb_query function of drivers/macintosh/adb.c,
req->data is copy form userland. The parameter
"req->data[2]" is Missing check, the array size of
adb_handler[] is 16, so "adb_handler[req->data[2]].
original_address" and "adb_handler[req->data[2]].
handler_id" will lead to oob read.

Signed-off-by: sohu0106 <sohu0106@126.com>
---
 drivers/macintosh/adb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
index 439fab4eaa85..1bbb9ca08d40 100644
--- a/drivers/macintosh/adb.c
+++ b/drivers/macintosh/adb.c
@@ -647,7 +647,7 @@ do_adb_query(struct adb_request *req)
 
 	switch(req->data[1]) {
 	case ADB_QUERY_GETDEVINFO:
-		if (req->nbytes < 3)
+		if (req->nbytes < 3 || req->data[2] >= 16)
 			break;
 		mutex_lock(&adb_handler_mutex);
 		req->reply[0] = adb_handler[req->data[2]].original_address;
-- 
2.25.1

Re: [PATCH] macintosh:fix oob read in do_adb_query function

[Greg KH]

On Wed, Jul 13, 2022 at 09:40:37PM +0800, NAME wrote:
> From: sohu0106 <sohu0106@126.com>

For obvious reasons, we need a real name here, and in the signed-off-by
line.

> In do_adb_query function of drivers/macintosh/adb.c,
> req->data is copy form userland. The parameter
> "req->data[2]" is Missing check, the array size of
> adb_handler[] is 16, so "adb_handler[req->data[2]].
> original_address" and "adb_handler[req->data[2]].
> handler_id" will lead to oob read.

You can use all 72 columns, if you want to re-wrap these lines when you
resend.

> 
> Signed-off-by: sohu0106 <sohu0106@126.com>
> ---
>  drivers/macintosh/adb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
> index 439fab4eaa85..1bbb9ca08d40 100644
> --- a/drivers/macintosh/adb.c
> +++ b/drivers/macintosh/adb.c
> @@ -647,7 +647,7 @@ do_adb_query(struct adb_request *req)
>  
>  	switch(req->data[1]) {
>  	case ADB_QUERY_GETDEVINFO:
> -		if (req->nbytes < 3)
> +		if (req->nbytes < 3 || req->data[2] >= 16)

Shouldn't 16 be the array size instead of having this hard coded to a
magic number?

Something like "sizeof(adb_handler) / sizeof(struct adb_handler)"?

Maybe not, that's messy, your choice.

thanks,

greg k-h

[PATCH] macintosh:fix oob read in do_adb_query function

[Ning Qiang]

In do_adb_query function of drivers/macintosh/adb.c, req->data is copy
form userland. the  parameter "req->data[2]" is Missing check, the
array size of adb_handler[] is 16, so "adb_handler[
req->data[2]].original_address" and "adb_handler[
req->data[2]].handler_id" will lead to oob read.

Signed-off-by: Ning Qiang <sohu0106@126.com>
---
 drivers/macintosh/adb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
index 439fab4eaa85..1bbb9ca08d40 100644
--- a/drivers/macintosh/adb.c
+++ b/drivers/macintosh/adb.c
@@ -647,7 +647,7 @@ do_adb_query(struct adb_request *req)
 
 	switch(req->data[1]) {
 	case ADB_QUERY_GETDEVINFO:
-		if (req->nbytes < 3)
+		if (req->nbytes < 3 || req->data[2] >= 16)
 			break;
 		mutex_lock(&adb_handler_mutex);
 		req->reply[0] = adb_handler[req->data[2]].original_address;
-- 
2.25.1

Re: [PATCH] macintosh:fix oob read in do_adb_query function

[Greg KH]

On Wed, Jul 13, 2022 at 11:37:34PM +0800, Ning Qiang wrote:
> In do_adb_query function of drivers/macintosh/adb.c, req->data is copy
> form userland. the  parameter "req->data[2]" is Missing check, the
> array size of adb_handler[] is 16, so "adb_handler[
> req->data[2]].original_address" and "adb_handler[
> req->data[2]].handler_id" will lead to oob read.
> 
> Signed-off-by: Ning Qiang <sohu0106@126.com>

Cc: stable <stable@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH] macintosh:fix oob read in do_adb_query function

[Kees Cook]

On Wed, Jul 13, 2022 at 11:37:34PM +0800, Ning Qiang wrote:
> In do_adb_query function of drivers/macintosh/adb.c, req->data is copy
> form userland. the  parameter "req->data[2]" is Missing check, the
> array size of adb_handler[] is 16, so "adb_handler[
> req->data[2]].original_address" and "adb_handler[
> req->data[2]].handler_id" will lead to oob read.
> 
> Signed-off-by: Ning Qiang <sohu0106@126.com>

Thanks for catching this!

Do you have a reproducer for this? I'd expect CONFIG_UBSAN_BOUNDS=y to
notice this at runtime, at least.


> ---
>  drivers/macintosh/adb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
> index 439fab4eaa85..1bbb9ca08d40 100644
> --- a/drivers/macintosh/adb.c
> +++ b/drivers/macintosh/adb.c
> @@ -647,7 +647,7 @@ do_adb_query(struct adb_request *req)
>  
>  	switch(req->data[1]) {
>  	case ADB_QUERY_GETDEVINFO:
> -		if (req->nbytes < 3)
> +		if (req->nbytes < 3 || req->data[2] >= 16)

I'd prefer this was:

+		if (req->nbytes < 3 || req->data[2] >= ARRAY_SIZE(adb_handler))

so it's tied to the actual variable (if its size ever changes).

With that:

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

>  			break;
>  		mutex_lock(&adb_handler_mutex);
>  		req->reply[0] = adb_handler[req->data[2]].original_address;
> -- 
> 2.25.1
> 

-- 
Kees Cook

Re: [PATCH] macintosh:fix oob read in do_adb_query function

[Benjamin Herrenschmidt]

On Wed, 2022-07-13 at 11:53 -0700, Kees Cook wrote:
> On Wed, Jul 13, 2022 at 11:37:34PM +0800, Ning Qiang wrote:
> > In do_adb_query function of drivers/macintosh/adb.c, req->data is
> > copy
> > form userland. the  parameter "req->data[2]" is Missing check, the
> > array size of adb_handler[] is 16, so "adb_handler[
> > req->data[2]].original_address" and "adb_handler[
> > req->data[2]].handler_id" will lead to oob read.
> > 
> > Signed-off-by: Ning Qiang <sohu0106@126.com>
> 
> Thanks for catching this!
> 
> Do you have a reproducer for this? I'd expect CONFIG_UBSAN_BOUNDS=y
> to notice this at runtime, at least.

For that you would need an ancient Mac with an ADB bus which might be
tricky ... I have some in the basement that could possibly be revived
if you really insist but I'd rather not waste the time...

Cheers,
Ben.

> 
> > ---
> >  drivers/macintosh/adb.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
> > index 439fab4eaa85..1bbb9ca08d40 100644
> > --- a/drivers/macintosh/adb.c
> > +++ b/drivers/macintosh/adb.c
> > @@ -647,7 +647,7 @@ do_adb_query(struct adb_request *req)
> >  
> >  	switch(req->data[1]) {
> >  	case ADB_QUERY_GETDEVINFO:
> > -		if (req->nbytes < 3)
> > +		if (req->nbytes < 3 || req->data[2] >= 16)
> 
> I'd prefer this was:
> 
> +		if (req->nbytes < 3 || req->data[2] >=
> ARRAY_SIZE(adb_handler))
> 
> so it's tied to the actual variable (if its size ever changes).
> 
> With that:
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> 
> -Kees
> 
> >  			break;
> >  		mutex_lock(&adb_handler_mutex);
> >  		req->reply[0] = adb_handler[req-
> > >data[2]].original_address;
> > -- 
> > 2.25.1
> > 

Re: [PATCH] macintosh:fix oob read in do_adb_query function

[Benjamin Herrenschmidt]

On Wed, 2022-07-13 at 23:37 +0800, Ning Qiang wrote:
> In do_adb_query function of drivers/macintosh/adb.c, req->data is
> copy
> form userland. the  parameter "req->data[2]" is Missing check, the
> array size of adb_handler[] is 16, so "adb_handler[
> req->data[2]].original_address" and "adb_handler[
> req->data[2]].handler_id" will lead to oob read.
> 
> Signed-off-by: Ning Qiang <sohu0106@126.com>

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

> ---
>  drivers/macintosh/adb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
> index 439fab4eaa85..1bbb9ca08d40 100644
> --- a/drivers/macintosh/adb.c
> +++ b/drivers/macintosh/adb.c
> @@ -647,7 +647,7 @@ do_adb_query(struct adb_request *req)
>  
>  	switch(req->data[1]) {
>  	case ADB_QUERY_GETDEVINFO:
> -		if (req->nbytes < 3)
> +		if (req->nbytes < 3 || req->data[2] >= 16)
>  			break;
>  		mutex_lock(&adb_handler_mutex);
>  		req->reply[0] = adb_handler[req-
> >data[2]].original_address;

Re: [PATCH] macintosh:fix oob read in do_adb_query function

[Michael Ellerman]

On Wed, 13 Jul 2022 23:37:34 +0800, Ning Qiang wrote:
> In do_adb_query function of drivers/macintosh/adb.c, req->data is copy
> form userland. the  parameter "req->data[2]" is Missing check, the
> array size of adb_handler[] is 16, so "adb_handler[
> req->data[2]].original_address" and "adb_handler[
> req->data[2]].handler_id" will lead to oob read.
> 
> 
> [...]

Applied to powerpc/next.

[1/1] macintosh:fix oob read in do_adb_query function
      https://git.kernel.org/powerpc/c/fd97e4ad6d3b0c9fce3bca8ea8e6969d9ce7423b

cheers