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FAILED: patch "[PATCH] usb: gadget: u_audio: fix race condition on endpoint stop" failed to apply to 4.14-stable tree

PATCH [email protected] 1 participant 1 message Aug 29, 2021

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The patch below does not apply to the 4.14-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 <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 068fdad20454f815e61e6f6eb9f051a8b3120e88 Mon Sep 17 00:00:00 2001
From: Jerome Brunet <[email protected]>
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 <[email protected]>
Reported-by Thinh Nguyen <[email protected]>
Signed-off-by Jerome Brunet <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
drivers/usb/gadget/function/u_audio.c +4 -4
index 63d9340f008e..9e5c950612d0 100644
@@ -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__);
 }