[PATCH v2] ks390/keyboard: use memdup_user_nul().

Muhammad Falak R Wani
2016-05-20T13:21:20Z

Use memdup_user_nul to duplicate a memory region from user-space
to kernel-space and terminate with a NULL, instead of open coding
using kmalloc + copy_from_user and explicitly NULL terminating.

Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
---
drivers/s390/char/keyboard.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/s390/char/keyboard.c b/drivers/s390/char/keyboard.c
index ef04a9f..f82a7dc 100644
--- a/drivers/s390/char/keyboard.c
+++ b/drivers/s390/char/keyboard.c
@@ -438,18 +438,13 @@ do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
return -EFAULT;
if (len > sizeof(u_kbs->kb_string))
return -EINVAL;
- p = kmalloc(len, GFP_KERNEL);
- if (!p)
- return -ENOMEM;
- if (copy_from_user(p, u_kbs->kb_string, len)) {
- kfree(p);
- return -EFAULT;
- }
+ p = memdup_user_nul(u_kbs->kb_string, len);
+ if (IS_ERR(p))
+ return PTR_ERR(p);
/*
* Make sure the string is terminated by 0. User could have
* modified it between us running strnlen_user() and copying it.
*/
- p[len - 1] = 0;
kfree(kbd->func_table[kb_func]);
kbd->func_table[kb_func] = p;
break;
--
1.9.1