4.19-stable review patch. If anyone has any objections, please let me know.
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From: Chris Wulff Chris.Wulff@biamp.com
[ Upstream commit a2cf936ebef291ef7395172b9e2f624779fb6dc0 ]
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 Link: https://lore.kernel.org/stable/CO1PR17MB54194226DA08BFC9EBD8C163E1172%40CO1P... Link: https://lore.kernel.org/r/CO1PR17MB54194226DA08BFC9EBD8C163E1172@CO1PR17MB54... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 3136a239e7828..f7c610b7e3fd3 100644 --- a/drivers/usb/gadget/function/u_audio.c +++ b/drivers/usb/gadget/function/u_audio.c @@ -624,6 +624,8 @@ 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);