FAILED: patch "[PATCH] usb: gadget: f_hid: fix device reference leak in hidg_alloc()" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] usb: gadget: f_hid: fix device reference leak in hidg_alloc()" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-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@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 4f88d65def6f3c90121601b4f62a4c967f3063a6
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026060453-blazer-sublet-0c66@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 4f88d65def6f3c90121601b4f62a4c967f3063a6 Mon Sep 17 00:00:00 2001
From: Guangshuo Li <lgs201920130244@gmail.com>
Date: Mon, 13 Apr 2026 22:21:19 +0800
Subject: [PATCH] usb: gadget: f_hid: fix device reference leak in hidg_alloc()

hidg_alloc() initializes hidg->dev with device_initialize() before
calling dev_set_name(). If dev_set_name() fails, the function currently
jumps to err_unlock and returns without calling put_device().

This leaves the device reference unbalanced and prevents hidg_release()
from being called. Calling put_device() here is also safe, since
hidg_release() only frees resources owned by hidg.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Route the dev_set_name() failure path through err_put_device so the
device reference is dropped properly.

Fixes: 89ff3dfac604 ("usb: gadget: f_hid: fix f_hidg lifetime vs cdev")
Cc: stable <stable@kernel.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Johan Hovold johan@kernel.org
Link: https://patch.msgid.link/20260413142119.2977716-1-lgs201920130244@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index c5a12a6760ea..3c6b43d06a6d 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -1622,7 +1622,7 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 	hidg->dev.devt = MKDEV(major, opts->minor);
 	ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
 	if (ret)
-		goto err_unlock;
+		goto err_put_device;
 
 	hidg->bInterfaceSubClass = opts->subclass;
 	hidg->bInterfaceProtocol = opts->protocol;
@@ -1659,7 +1659,6 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 
 err_put_device:
 	put_device(&hidg->dev);
-err_unlock:
 	mutex_unlock(&opts->lock);
 	return ERR_PTR(ret);
 }

[PATCH 5.10.y 1/2] usb: gadget: f_hid: tidy error handling in hidg_alloc

[Sasha Levin]

From: John Keeping <john@metanate.com>

[ Upstream commit 944fe915d00d3cb1bacb1e77cabfb6dc82e6f8b8 ]

Unify error handling at the end of the function, reducing the risk of
missing something on one of the error paths.

Moving the increment of opts->refcnt later means there is no need to
decrement it on the error path and is safe as this is guarded by
opts->lock which is held for this entire section.

Tested-by: Lee Jones <lee@kernel.org>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Lee Jones <lee@kernel.org>
Signed-off-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20221122123523.3068034-4-john@metanate.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 4f88d65def6f ("usb: gadget: f_hid: fix device reference leak in hidg_alloc()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/function/f_hid.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index e3738a1aa9f483..7c5916caf61b30 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -1265,7 +1265,6 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 	opts = container_of(fi, struct f_hid_opts, func_inst);
 
 	mutex_lock(&opts->lock);
-	++opts->refcnt;
 
 	spin_lock_init(&hidg->write_spinlock);
 	spin_lock_init(&hidg->read_spinlock);
@@ -1278,11 +1277,8 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 	hidg->dev.class = hidg_class;
 	hidg->dev.devt = MKDEV(major, opts->minor);
 	ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
-	if (ret) {
-		--opts->refcnt;
-		mutex_unlock(&opts->lock);
-		return ERR_PTR(ret);
-	}
+	if (ret)
+		goto err_unlock;
 
 	hidg->bInterfaceSubClass = opts->subclass;
 	hidg->bInterfaceProtocol = opts->protocol;
@@ -1293,14 +1289,13 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 					    opts->report_desc_length,
 					    GFP_KERNEL);
 		if (!hidg->report_desc) {
-			put_device(&hidg->dev);
-			--opts->refcnt;
-			mutex_unlock(&opts->lock);
-			return ERR_PTR(-ENOMEM);
+			ret = -ENOMEM;
+			goto err_put_device;
 		}
 	}
 	hidg->use_out_ep = !opts->no_out_endpoint;
 
+	++opts->refcnt;
 	mutex_unlock(&opts->lock);
 
 	hidg->func.name    = "hid";
@@ -1315,6 +1310,12 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 	hidg->qlen	   = 4;
 
 	return &hidg->func;
+
+err_put_device:
+	put_device(&hidg->dev);
+err_unlock:
+	mutex_unlock(&opts->lock);
+	return ERR_PTR(ret);
 }
 
 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
-- 
2.53.0

[PATCH 5.10.y 2/2] usb: gadget: f_hid: fix device reference leak in hidg_alloc()

[Sasha Levin]

From: Guangshuo Li <lgs201920130244@gmail.com>

[ Upstream commit 4f88d65def6f3c90121601b4f62a4c967f3063a6 ]

hidg_alloc() initializes hidg->dev with device_initialize() before
calling dev_set_name(). If dev_set_name() fails, the function currently
jumps to err_unlock and returns without calling put_device().

This leaves the device reference unbalanced and prevents hidg_release()
from being called. Calling put_device() here is also safe, since
hidg_release() only frees resources owned by hidg.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Route the dev_set_name() failure path through err_put_device so the
device reference is dropped properly.

Fixes: 89ff3dfac604 ("usb: gadget: f_hid: fix f_hidg lifetime vs cdev")
Cc: stable <stable@kernel.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Johan Hovold johan@kernel.org
Link: https://patch.msgid.link/20260413142119.2977716-1-lgs201920130244@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/function/f_hid.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 7c5916caf61b30..d5ff9f06c68622 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -1278,7 +1278,7 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 	hidg->dev.devt = MKDEV(major, opts->minor);
 	ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
 	if (ret)
-		goto err_unlock;
+		goto err_put_device;
 
 	hidg->bInterfaceSubClass = opts->subclass;
 	hidg->bInterfaceProtocol = opts->protocol;
@@ -1313,7 +1313,6 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 
 err_put_device:
 	put_device(&hidg->dev);
-err_unlock:
 	mutex_unlock(&opts->lock);
 	return ERR_PTR(ret);
 }
-- 
2.53.0