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From 61890dc28f7d9e9aac8a9471302613824c22fae4 Mon Sep 17 00:00:00 2001
From: Konstantin Aladyshev <aladyshev22@gmail.com>
Date: Wed, 6 Dec 2023 11:07:44 +0300
Subject: [PATCH] usb: gadget: f_hid: fix report descriptor allocation
Git-commit: 61890dc28f7d9e9aac8a9471302613824c22fae4
Patch-mainline: v6.7-rc5
References: git-fixes

The commit 89ff3dfac604 ("usb: gadget: f_hid: fix f_hidg lifetime vs
cdev") has introduced a bug that leads to hid device corruption after
the replug operation.
Reverse device managed memory allocation for the report descriptor
to fix the issue.

Tested: 
This change was tested on the AMD EthanolX CRB server with the BMC
based on the OpenBMC distribution. The BMC provides KVM functionality
via the USB gadget device:
- before: KVM page refresh results in a broken USB device,
- after: KVM page refresh works without any issues.

Fixes: 89ff3dfac604 ("usb: gadget: f_hid: fix f_hidg lifetime vs cdev")
Cc: stable@vger.kernel.org
Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Link: https://lore.kernel.org/r/20231206080744.253-2-aladyshev22@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/usb/gadget/function/f_hid.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index ea85e2c701a1..3c8a9dd585c0 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -92,6 +92,7 @@ static void hidg_release(struct device *dev)
 {
 	struct f_hidg *hidg = container_of(dev, struct f_hidg, dev);
 
+	kfree(hidg->report_desc);
 	kfree(hidg->set_report_buf);
 	kfree(hidg);
 }
@@ -1287,9 +1288,9 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 	hidg->report_length = opts->report_length;
 	hidg->report_desc_length = opts->report_desc_length;
 	if (opts->report_desc) {
-		hidg->report_desc = devm_kmemdup(&hidg->dev, opts->report_desc,
-						 opts->report_desc_length,
-						 GFP_KERNEL);
+		hidg->report_desc = kmemdup(opts->report_desc,
+					    opts->report_desc_length,
+					    GFP_KERNEL);
 		if (!hidg->report_desc) {
 			ret = -ENOMEM;
 			goto err_put_device;
-- 
2.35.3