From f6af820ef1be58c2e4b81aa479b9f109eb6344ce Mon Sep 17 00:00:00 2001
From: Fuqian Huang <huangfq.daxian@gmail.com>
Date: Wed, 3 Jul 2019 13:28:37 -0300
Subject: [PATCH] media: media/dvb: Use kmemdup rather than duplicating its implementation
Git-commit: f6af820ef1be58c2e4b81aa479b9f109eb6344ce
Patch-mainline: v5.4-rc1
References: CVE-2022-45884 bsc#1205756

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memcpy, which the programmer needs to
write the size twice (sometimes lead to mistakes), kmemdup improves
readability, leads to smaller code and also reduce the chances of mistakes.
Suggestion to use kmemdup rather than using kmalloc/kzalloc + memcpy.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/dvb-core/dvbdev.c             | 3 +--
 drivers/media/dvb-frontends/drx39xyj/drxj.c | 5 ++---
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c
index a3393cd4e584..d7532f5a352a 100644
--- a/drivers/media/dvb-core/dvbdev.c
+++ b/drivers/media/dvb-core/dvbdev.c
@@ -476,7 +476,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 		return -ENOMEM;
 	}
 
-	dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
+	dvbdevfops = kmemdup(template->fops, sizeof(*dvbdevfops), GFP_KERNEL);
 
 	if (!dvbdevfops){
 		kfree (dvbdev);
@@ -492,7 +492,6 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 	dvbdev->fops = dvbdevfops;
 	init_waitqueue_head (&dvbdev->wait_queue);
 
-	memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
 	dvbdevfops->owner = adap->module;
 
 	list_add_tail (&dvbdev->list_head, &adap->device_list);
diff --git a/drivers/media/dvb-frontends/drx39xyj/drxj.c b/drivers/media/dvb-frontends/drx39xyj/drxj.c
index a6876fa48753..2f5af4813a74 100644
--- a/drivers/media/dvb-frontends/drx39xyj/drxj.c
+++ b/drivers/media/dvb-frontends/drx39xyj/drxj.c
@@ -12287,7 +12287,8 @@ struct dvb_frontend *drx39xxj_attach(struct i2c_adapter *i2c)
 	if (state == NULL)
 		goto error;
 
-	demod = kmalloc(sizeof(struct drx_demod_instance), GFP_KERNEL);
+	demod = kmemdup(&drxj_default_demod_g,
+			sizeof(struct drx_demod_instance), GFP_KERNEL);
 	if (demod == NULL)
 		goto error;
 
@@ -12311,8 +12312,6 @@ struct dvb_frontend *drx39xxj_attach(struct i2c_adapter *i2c)
 	state->demod = demod;
 
 	/* setup the demod data */
-	memcpy(demod, &drxj_default_demod_g, sizeof(struct drx_demod_instance));
-
 	demod->my_i2c_dev_addr = demod_addr;
 	demod->my_common_attr = demod_comm_attr;
 	demod->my_i2c_dev_addr->user_data = state;
-- 
2.35.3