| Message ID | ZRb2CKHuaCu0u38i@work |
|---|---|
| State | New |
| Headers | show |
| Series | [next] ALSA: 6fire: Fix undefined behavior bug in struct midi_runtime | expand |
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: stable@vger.kernel.org >> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > > Another good find. :) There are more coming. :) > > Reviewed-by: Kees Cook <keescook@chromium.org> > Thanks! -- Gustavo
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: stable@vger.kernel.org > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> 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 >
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);
`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: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- sound/usb/6fire/midi.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)