diff mbox series

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

Message ID 20240424-fix-oob-read-v2-5-f1f1b53a10f4@gmail.com
State Handled Elsewhere
Headers show
Series Ensure the copied buf is NUL terminated | expand

Commit Message

Bui Quang Minh April 24, 2024, 2:44 p.m. UTC
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 <minhquangbui99@gmail.com>
---
 drivers/s390/cio/cio_inject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Heiko Carstens April 24, 2024, 2:54 p.m. UTC | #1
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 <minhquangbui99@gmail.com>
> ---
>  drivers/s390/cio/cio_inject.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Alexander Gordeev April 24, 2024, 3:16 p.m. UTC | #2
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 <minhquangbui99@gmail.com>
> ---
>  drivers/s390/cio/cio_inject.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks!
Alexander Gordeev April 26, 2024, 10:10 a.m. UTC | #3
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!
Jakub Kicinski April 26, 2024, 2:29 p.m. UTC | #4
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 :)
diff mbox series

Patch

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;