2024-04-24 14:46:49

by Bui Quang Minh

Subject: [PATCH v2 5/6] cio: ensure the copied buf is NUL terminated

Currently, we allocate a lbuf-sized kernel buffer and copy lbuf from
userspace to that buffer. Later, we use scanf on this buffer but we don't
ensure that the string is terminated inside the buffer, this can lead to
OOB read when using scanf. Fix this issue by using memdup_user_nul instead.

Fixes: a4f17cc72671 ("s390/cio: add CRW inject functionality")
Signed-off-by: Bui Quang Minh <[email protected]>
---
drivers/s390/cio/cio_inject.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/cio/cio_inject.c b/drivers/s390/cio/cio_inject.c
index 8613fa937237..a2e771ebae8e 100644
--- a/drivers/s390/cio/cio_inject.c
+++ b/drivers/s390/cio/cio_inject.c
@@ -95,7 +95,7 @@ static ssize_t crw_inject_write(struct file *file, const char __user *buf,
return -EINVAL;
}

- buffer = vmemdup_user(buf, lbuf);
+ buffer = memdup_user_nul(buf, lbuf);
if (IS_ERR(buffer))
return -ENOMEM;


--
2.34.1

2024-04-24 15:00:01

by Heiko Carstens

Subject: Re: [PATCH v2 5/6] cio: ensure the copied buf is NUL terminated

On Wed, Apr 24, 2024 at 09:44:22PM +0700, Bui Quang Minh wrote:
> Currently, we allocate a lbuf-sized kernel buffer and copy lbuf from
> userspace to that buffer. Later, we use scanf on this buffer but we don't
> ensure that the string is terminated inside the buffer, this can lead to
> OOB read when using scanf. Fix this issue by using memdup_user_nul instead.
>
> Fixes: a4f17cc72671 ("s390/cio: add CRW inject functionality")
> Signed-off-by: Bui Quang Minh <[email protected]>
> ---
> drivers/s390/cio/cio_inject.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Heiko Carstens <[email protected]>

2024-04-24 15:17:46

by Alexander Gordeev

Subject: Re: [PATCH v2 5/6] cio: ensure the copied buf is NUL terminated

On Wed, Apr 24, 2024 at 09:44:22PM +0700, Bui Quang Minh wrote:
> Currently, we allocate a lbuf-sized kernel buffer and copy lbuf from
> userspace to that buffer. Later, we use scanf on this buffer but we don't
> ensure that the string is terminated inside the buffer, this can lead to
> OOB read when using scanf. Fix this issue by using memdup_user_nul instead.
>
> Fixes: a4f17cc72671 ("s390/cio: add CRW inject functionality")
> Signed-off-by: Bui Quang Minh <[email protected]>
> ---
> drivers/s390/cio/cio_inject.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks!

2024-04-26 10:18:49

by Alexander Gordeev

Subject: Re: [PATCH v2 5/6] cio: ensure the copied buf is NUL terminated

On Wed, Apr 24, 2024 at 05:16:56PM +0200, Alexander Gordeev wrote:
> Applied, thanks!

Hi Jakub,

I just want to make sure you do not have plans to pull this patch
via the net tree, right? (I schedulled it for the s390 tree already).

Thanks!

2024-04-26 14:30:01

by Jakub Kicinski

Subject: Re: [PATCH v2 5/6] cio: ensure the copied buf is NUL terminated

On Fri, 26 Apr 2024 12:10:35 +0200 Alexander Gordeev wrote:
> On Wed, Apr 24, 2024 at 05:16:56PM +0200, Alexander Gordeev wrote:
> > Applied, thanks!
>
> Hi Jakub,
>
> I just want to make sure you do not have plans to pull this patch
> via the net tree, right? (I schedulled it for the s390 tree already).

Yes, go for it. I picked 1, 2 and 6, no interest in the other 3 :)