The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 068fdad20454f815e61e6f6eb9f051a8b3120e88 Mon Sep 17 00:00:00 2001
From: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Date: Fri, 27 Aug 2021 11:29:27 +0200
Subject: [PATCH] usb: gadget: u_audio: fix race condition on endpoint stop
If the endpoint completion callback is call right after the ep_enabled flag
is cleared and before usb_ep_dequeue() is call, we could do a double free
on the request and the associated buffer.
Fix this by clearing ep_enabled after all the endpoint requests have been
dequeued.
Fixes: 7de8681be2cd ("usb: gadget: u_audio: Free requests only after callback")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Reported-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210827092927.366482-1-jbrunet@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
index 63d9340f008e..9e5c950612d0 100644
--- a/drivers/usb/gadget/function/u_audio.c
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -394,8 +394,6 @@ static inline void free_ep(struct uac_rtd_params *prm, struct usb_ep *ep)
if (!prm->ep_enabled)
return;
- prm->ep_enabled = false;
-
audio_dev = uac->audio_dev;
params = &audio_dev->params;
@@ -413,6 +411,8 @@ static inline void free_ep(struct uac_rtd_params *prm, struct usb_ep *ep)
}
}
+ prm->ep_enabled = false;
+
if (usb_ep_disable(ep))
dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__);
}
@@ -424,8 +424,6 @@ static inline void free_ep_fback(struct uac_rtd_params *prm, struct usb_ep *ep)
if (!prm->fb_ep_enabled)
return;
- prm->fb_ep_enabled = false;
-
if (prm->req_fback) {
if (usb_ep_dequeue(ep, prm->req_fback)) {
kfree(prm->req_fback->buf);
@@ -434,6 +432,8 @@ static inline void free_ep_fback(struct uac_rtd_params *prm, struct usb_ep *ep)
prm->req_fback = NULL;
}
+ prm->fb_ep_enabled = false;
+
if (usb_ep_disable(ep))
dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__);
}
