[PATCH] usb: gadget: u_audio: Clear uac pointer when freed.

[PATCH] usb: gadget: u_audio: Clear uac pointer when freed.

[Chris Wulff]

This prevents use of a stale pointer if functions are called after
g_cleanup that shouldn't be. This doesn't fix any races, but converts
a possibly silent kernel memory corruption into an obvious NULL pointer
dereference report.

Fixes: eb9fecb9e69b ("usb: gadget: f_uac2: split out audio core")
Signed-off-by: Chris Wulff <chris.wulff@biamp.com>
---
v1: Split from https://lore.kernel.org/linux-usb/CO1PR17MB54190B898057616EEB3F9E51E10E2@CO1PR17MB5419.namprd17.prod.outlook.com/

 drivers/usb/gadget/function/u_audio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
index c8e8154c59f5..ec1dceb08729 100644
--- a/drivers/usb/gadget/function/u_audio.c
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -1419,6 +1419,8 @@ void g_audio_cleanup(struct g_audio *g_audio)
 		return;
 
 	uac = g_audio->uac;
+	g_audio->uac = NULL;
+
 	card = uac->card;
 	if (card)
 		snd_card_free_when_closed(card);
-- 
2.34.1

Re: [PATCH] usb: gadget: u_audio: Clear uac pointer when freed.

[kernel test robot]

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-1

Rule: add the tag "Cc: stable@vger.kernel.org" in the sign-off area to have the patch automatically included in the stable tree.
Subject: [PATCH] usb: gadget: u_audio: Clear uac pointer when freed.
Link: https://lore.kernel.org/stable/CO1PR17MB54194226DA08BFC9EBD8C163E1172%40CO1PR17MB5419.namprd17.prod.outlook.com

-- 
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https://github.com/intel/lkp-tests/wiki