Navid Emamdoost wrote:
On Mon, Oct 28, 2019 at 1:27 AM Takashi Iwai tiwai@suse.de wrote:
On Sun, 27 Oct 2019 23:10:06 +0100, Navid Emamdoost wrote:
In the implementation of __snd_usbmidi_create() there is a memory leak caused by incorrect goto destination. Go to free_midi if snd_usbmidi_create_endpoints_midiman() or snd_usbmidi_create_endpoints() fail.
No, this will lead to double-free. After registering the rawmidi interface at snd_usbmidi_create_rawmidi(), the common destructor will be called via rawmidi private_free callback, and this will release the all resources already.
Now I can see how rawmidi private_free is set up to release the resources, but what concerns me is that at the moment of endpoint/port creation umidi is not yet added to the midi_list. In other words, what I see is that we still have just one local pointer to umidi if any of snd_usbmidi_create_endpoint* fail.
The snd_rawmidi device is automatically registered with the card, so the line "rmidi->private_free = snd_usbmidi_rawmidi_free;" is the exact point where the ownership of umidi changes. midi_list does not matter.
Regards, Clemens