Commit 3bd82605 authored Dec 17, 2019 by Pratham Pratap

usb: gadget: f_midi: Avoid invalid pointer access



Currently f_midi function driver is marking the f_midi->card
NULL when the card is unregistered. There is a possibility that
alsa_show is called after the card is unregistered which can lead
to page fault since midi->card is assigned to rmidi->card. Avoid
this by adding midi->card pointer check in alsa_show.

Change-Id: I24fd35fb9cd35fcd5d8698b808459310b09675f9
Signed-off-by: Pratham Pratap <prathampratap@codeaurora.org>

parent 041ae774

drivers/usb/gadget/function/f_midi.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1235,7 +1235,7 @@ static ssize_t alsa_show(struct device *dev,

		if (fi_midi && fi_midi->f) {
		midi = func_to_midi(fi_midi->f);
		if (midi->rmidi && midi->rmidi->card)
		if (midi->rmidi && midi->card && midi->rmidi->card)
		return sprintf(buf, "%d %d\n",
		midi->rmidi->card->number, midi->rmidi->device);
		}