`struct urb` is a flexible structure, which means that it contains a
flexible-array member at the bottom. This could potentially lead to an
overwrite of the objects following `out_urb` in `struct midi_runtime`,
among them a function pointer.
Fix this by placing the declaration of object `out_urb` at the end of
`struct midi_runtime`.
Fixes: c6d43ba816d1 ("ALSA: usb/6fire - Driver for TerraTec DMX 6Fire USB")
Cc: [email protected]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
sound/usb/6fire/midi.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/usb/6fire/midi.h b/sound/usb/6fire/midi.h
index 47640c845903..df3f41913274 100644
--- a/sound/usb/6fire/midi.h
+++ b/sound/usb/6fire/midi.h
@@ -22,12 +22,12 @@ struct midi_runtime {
spinlock_t in_lock;
spinlock_t out_lock;
struct snd_rawmidi_substream *out;
- struct urb out_urb;
u8 out_serial; /* serial number of out packet */
u8 *out_buffer;
int buffer_offset;
void (*in_received)(struct midi_runtime *rt, u8 *data, int length);
+ struct urb out_urb;
};
int usb6fire_midi_init(struct sfire_chip *chip);
--
2.34.1
On 9/29/23 19:27, Kees Cook wrote:
> On Fri, Sep 29, 2023 at 06:06:32PM +0200, Gustavo A. R. Silva wrote:
>> `struct urb` is a flexible structure, which means that it contains a
>> flexible-array member at the bottom. This could potentially lead to an
>> overwrite of the objects following `out_urb` in `struct midi_runtime`,
>> among them a function pointer.
>>
>> Fix this by placing the declaration of object `out_urb` at the end of
>> `struct midi_runtime`.
>>
>> Fixes: c6d43ba816d1 ("ALSA: usb/6fire - Driver for TerraTec DMX 6Fire USB")
>> Cc: [email protected]
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>
> Another good find. :)
There are more coming. :)
>
> Reviewed-by: Kees Cook <[email protected]>
>
Thanks!
--
Gustavo
On Fri, Sep 29, 2023 at 06:06:32PM +0200, Gustavo A. R. Silva wrote:
> `struct urb` is a flexible structure, which means that it contains a
> flexible-array member at the bottom. This could potentially lead to an
> overwrite of the objects following `out_urb` in `struct midi_runtime`,
> among them a function pointer.
>
> Fix this by placing the declaration of object `out_urb` at the end of
> `struct midi_runtime`.
>
> Fixes: c6d43ba816d1 ("ALSA: usb/6fire - Driver for TerraTec DMX 6Fire USB")
> Cc: [email protected]
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
Another good find. :)
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook
On Fri, 29 Sep 2023 18:06:32 +0200,
Gustavo A. R. Silva wrote:
>
> `struct urb` is a flexible structure, which means that it contains a
> flexible-array member at the bottom. This could potentially lead to an
> overwrite of the objects following `out_urb` in `struct midi_runtime`,
> among them a function pointer.
>
> Fix this by placing the declaration of object `out_urb` at the end of
> `struct midi_runtime`.
>
> Fixes: c6d43ba816d1 ("ALSA: usb/6fire - Driver for TerraTec DMX 6Fire USB")
> Cc: [email protected]
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
The same question as your another 6fire patch is applied here: does it
"fix" anything real?
thanks,
Takashi
> ---
> sound/usb/6fire/midi.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/sound/usb/6fire/midi.h b/sound/usb/6fire/midi.h
> index 47640c845903..df3f41913274 100644
> --- a/sound/usb/6fire/midi.h
> +++ b/sound/usb/6fire/midi.h
> @@ -22,12 +22,12 @@ struct midi_runtime {
> spinlock_t in_lock;
> spinlock_t out_lock;
> struct snd_rawmidi_substream *out;
> - struct urb out_urb;
> u8 out_serial; /* serial number of out packet */
> u8 *out_buffer;
> int buffer_offset;
>
> void (*in_received)(struct midi_runtime *rt, u8 *data, int length);
> + struct urb out_urb;
> };
>
> int usb6fire_midi_init(struct sfire_chip *chip);
> --
> 2.34.1
>