* [PATCH] ks390/keyboard: use memdup_user().
@ 2016-05-20 12:22 Muhammad Falak R Wani
2016-05-20 13:03 ` Heiko Carstens
0 siblings, 1 reply; 3+ messages in thread
From: Muhammad Falak R Wani @ 2016-05-20 12:22 UTC (permalink / raw)
To: Heiko Carstens; +Cc: Martin Schwidefsky, Jan Kara, open list:S390, open list
Use memdup_user to duplicate a memory region from user-space to
kernel-space, instead of open coding using kmalloc & copy_from_user.
Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
---
drivers/s390/char/keyboard.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/s390/char/keyboard.c b/drivers/s390/char/keyboard.c
index ef04a9f..2955983 100644
--- a/drivers/s390/char/keyboard.c
+++ b/drivers/s390/char/keyboard.c
@@ -438,13 +438,9 @@ 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(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.
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ks390/keyboard: use memdup_user().
2016-05-20 12:22 [PATCH] ks390/keyboard: use memdup_user() Muhammad Falak R Wani
@ 2016-05-20 13:03 ` Heiko Carstens
2016-05-20 13:07 ` Muhammad Falak R Wani
0 siblings, 1 reply; 3+ messages in thread
From: Heiko Carstens @ 2016-05-20 13:03 UTC (permalink / raw)
To: Muhammad Falak R Wani
Cc: Martin Schwidefsky, Jan Kara, open list:S390, open list
On Fri, May 20, 2016 at 05:52:16PM +0530, Muhammad Falak R Wani wrote:
> Use memdup_user to duplicate a memory region from user-space to
> kernel-space, instead of open coding using kmalloc & copy_from_user.
>
> Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
> ---
> drivers/s390/char/keyboard.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/s390/char/keyboard.c b/drivers/s390/char/keyboard.c
> index ef04a9f..2955983 100644
> --- a/drivers/s390/char/keyboard.c
> +++ b/drivers/s390/char/keyboard.c
> @@ -438,13 +438,9 @@ 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(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.
Hi Muhammad, thanks for this patch. However could you change this to use
memdup_user_nul() instead, so we can get rid of even more code?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ks390/keyboard: use memdup_user().
2016-05-20 13:03 ` Heiko Carstens
@ 2016-05-20 13:07 ` Muhammad Falak R Wani
0 siblings, 0 replies; 3+ messages in thread
From: Muhammad Falak R Wani @ 2016-05-20 13:07 UTC (permalink / raw)
To: Heiko Carstens; +Cc: Martin Schwidefsky, Jan Kara, open list:S390, open list
On Fri, May 20, 2016 at 03:03:25PM +0200, Heiko Carstens wrote:
> On Fri, May 20, 2016 at 05:52:16PM +0530, Muhammad Falak R Wani wrote:
> > Use memdup_user to duplicate a memory region from user-space to
> > kernel-space, instead of open coding using kmalloc & copy_from_user.
> >
> > Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
> > + p = memdup_user(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.
>
> Hi Muhammad, thanks for this patch. However could you change this to use
> memdup_user_nul() instead, so we can get rid of even more code?
>
Should I send V2 with the suggested changes ?
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-05-20 12:22 [PATCH] ks390/keyboard: use memdup_user() Muhammad Falak R Wani
2016-05-20 13:03 ` Heiko Carstens
2016-05-20 13:07 ` Muhammad Falak R Wani
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