media: media/dvb: Use kmemdup rather than duplicating its implementation

[ Upstream commit f6af820ef1be58c2e4b81aa479b9f109eb6344ce ]

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>
Stable-dep-of: 8c64f4cdf4e6 ("media: edia: dvbdev: fix a use-after-free")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Fuqian Huang
2019-07-03 13:28:37 -03:00
committed by Sasha Levin
parent cfa5ffc57e
commit 6e4129f816
2 changed files with 3 additions and 5 deletions

View File

@@ -485,7 +485,7 @@ 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);
@@ -502,7 +502,6 @@ 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);

View File

@@ -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;