On Wed, 13 Nov 2019 11:19:54 +0100, Pavel Machek wrote: > > Hi! > > > From: Takashi Iwai <tiwai@xxxxxxx> > > > > commit 60849562a5db4a1eee2160167e4dce4590d3eafe upstream. > > > > The previous addition of descriptor validation may lead to a NULL > > dereference at create_yamaha_midi_quirk() when either injd or outjd is > > NULL. Add proper non-NULL checks. > > This is wrong. > > > @@ -259,8 +259,8 @@ static int create_yamaha_midi_quirk(stru > > NULL, USB_MS_MIDI_OUT_JACK); > > if (!injd && !outjd) > > return -ENODEV; > > Clearly code wants to allow at most one of them to be NULL. > > > - if (!snd_usb_validate_midi_desc(injd) || > > - !snd_usb_validate_midi_desc(outjd)) > > + if (!(injd && snd_usb_validate_midi_desc(injd)) || > > + !(outjd && snd_usb_validate_midi_desc(outjd))) > > return -ENODEV; > > Yet it will return here if it is. Correct check would be > > + if (!(!injd || snd_usb_validate_midi_desc(injd)) || > + !(!outjd || snd_usb_validate_midi_desc(outjd))) > > AFAICT. Erm, right, but a better representation is: if ((injd && !snd_usb_validate_midi_desc(injd)) || (outjd && !snd_usb_validate_midi_desc(injd))) thanks, Takashi
