* [PATCH v2] drm: return -EFAULT if copy_to_user() fails
[not found] <20190618125623.GA24896@mwanda>
@ 2019-06-18 13:18 ` Dan Carpenter
2019-06-18 17:16 ` Sean Paul
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2019-06-18 13:18 UTC (permalink / raw)
To: Al Viro
Cc: Maarten Lankhorst, Maxime Ripard, Sean Paul, David Airlie,
Daniel Vetter, dri-devel, linux-kernel, kernel-janitors
The copy_from_user() function returns the number of bytes remaining
to be copied but we want to return a negative error code. Otherwise
the callers treat it as a successful copy.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: The first version was missing a chunk
drivers/gpu/drm/drm_bufs.c | 5 ++++-
drivers/gpu/drm/drm_ioc32.c | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 68dacf8422c6..8ce9d73fab4f 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -1351,7 +1351,10 @@ static int copy_one_buf(void *data, int count, struct drm_buf_entry *from)
.size = from->buf_size,
.low_mark = from->low_mark,
.high_mark = from->high_mark};
- return copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags));
+
+ if (copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags)))
+ return -EFAULT;
+ return 0;
}
int drm_legacy_infobufs(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
index 586aa28024c5..a16b6dc2fa47 100644
--- a/drivers/gpu/drm/drm_ioc32.c
+++ b/drivers/gpu/drm/drm_ioc32.c
@@ -378,7 +378,10 @@ static int copy_one_buf32(void *data, int count, struct drm_buf_entry *from)
.size = from->buf_size,
.low_mark = from->low_mark,
.high_mark = from->high_mark};
- return copy_to_user(to + count, &v, offsetof(drm_buf_desc32_t, flags));
+
+ if (copy_to_user(to + count, &v, offsetof(drm_buf_desc32_t, flags)))
+ return -EFAULT;
+ return 0;
}
static int drm_legacy_infobufs32(struct drm_device *dev, void *data,
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] drm: return -EFAULT if copy_to_user() fails
2019-06-18 13:18 ` [PATCH v2] drm: return -EFAULT if copy_to_user() fails Dan Carpenter
@ 2019-06-18 17:16 ` Sean Paul
2019-06-25 23:18 ` Al Viro
0 siblings, 1 reply; 3+ messages in thread
From: Sean Paul @ 2019-06-18 17:16 UTC (permalink / raw)
To: Dan Carpenter
Cc: Al Viro, Maarten Lankhorst, Maxime Ripard, Sean Paul,
David Airlie, Daniel Vetter, dri-devel, linux-kernel,
kernel-janitors
On Tue, Jun 18, 2019 at 04:18:43PM +0300, Dan Carpenter wrote:
> The copy_from_user() function returns the number of bytes remaining
> to be copied but we want to return a negative error code. Otherwise
> the callers treat it as a successful copy.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Thanks Dan, I've applied this to drm-misc-fixes.
Sean
> ---
> v2: The first version was missing a chunk
>
> drivers/gpu/drm/drm_bufs.c | 5 ++++-
> drivers/gpu/drm/drm_ioc32.c | 5 ++++-
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
> index 68dacf8422c6..8ce9d73fab4f 100644
> --- a/drivers/gpu/drm/drm_bufs.c
> +++ b/drivers/gpu/drm/drm_bufs.c
> @@ -1351,7 +1351,10 @@ static int copy_one_buf(void *data, int count, struct drm_buf_entry *from)
> .size = from->buf_size,
> .low_mark = from->low_mark,
> .high_mark = from->high_mark};
> - return copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags));
> +
> + if (copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags)))
> + return -EFAULT;
> + return 0;
> }
>
> int drm_legacy_infobufs(struct drm_device *dev, void *data,
> diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
> index 586aa28024c5..a16b6dc2fa47 100644
> --- a/drivers/gpu/drm/drm_ioc32.c
> +++ b/drivers/gpu/drm/drm_ioc32.c
> @@ -378,7 +378,10 @@ static int copy_one_buf32(void *data, int count, struct drm_buf_entry *from)
> .size = from->buf_size,
> .low_mark = from->low_mark,
> .high_mark = from->high_mark};
> - return copy_to_user(to + count, &v, offsetof(drm_buf_desc32_t, flags));
> +
> + if (copy_to_user(to + count, &v, offsetof(drm_buf_desc32_t, flags)))
> + return -EFAULT;
> + return 0;
> }
>
> static int drm_legacy_infobufs32(struct drm_device *dev, void *data,
> --
> 2.20.1
>
--
Sean Paul, Software Engineer, Google / Chromium OS
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] drm: return -EFAULT if copy_to_user() fails
2019-06-18 17:16 ` Sean Paul
@ 2019-06-25 23:18 ` Al Viro
0 siblings, 0 replies; 3+ messages in thread
From: Al Viro @ 2019-06-25 23:18 UTC (permalink / raw)
To: Sean Paul
Cc: Dan Carpenter, Maarten Lankhorst, Maxime Ripard, David Airlie,
Daniel Vetter, dri-devel, linux-kernel, kernel-janitors
On Tue, Jun 18, 2019 at 01:16:29PM -0400, Sean Paul wrote:
> On Tue, Jun 18, 2019 at 04:18:43PM +0300, Dan Carpenter wrote:
> > The copy_from_user() function returns the number of bytes remaining
> > to be copied but we want to return a negative error code. Otherwise
> > the callers treat it as a successful copy.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> Thanks Dan, I've applied this to drm-misc-fixes.
FWIW, Acked-by: Al Viro <viro@zeniv.linux.org.uk>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-06-18 13:18 ` [PATCH v2] drm: return -EFAULT if copy_to_user() fails Dan Carpenter
2019-06-18 17:16 ` Sean Paul
2019-06-25 23:18 ` Al Viro
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