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 <[email protected]> --- 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
