diff mbox

drm: remove redundant code form drm_ioc32.c

Message ID 1435742677-14158-1-git-send-email-jarkko.sakkinen@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jarkko Sakkinen July 1, 2015, 9:24 a.m. UTC
The compat ioctl handler ends up calling access_ok() twice: first
indirectly inside compat_alloc_user_space() and then after returning
from that function. This patch fixes issue.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/gpu/drm/drm_ioc32.c | 55 +++++++++++++++++++++------------------------
 1 file changed, 26 insertions(+), 29 deletions(-)

Comments

Daniel Vetter July 2, 2015, 7:32 a.m. UTC | #1
On Wed, Jul 01, 2015 at 12:24:37PM +0300, Jarkko Sakkinen wrote:
> The compat ioctl handler ends up calling access_ok() twice: first
> indirectly inside compat_alloc_user_space() and then after returning
> from that function. This patch fixes issue.
> 
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Applied to topic/drm-misc, thanks. Btw is this generated with some cocci
script or not?
-Daniel

> ---
>  drivers/gpu/drm/drm_ioc32.c | 55 +++++++++++++++++++++------------------------
>  1 file changed, 26 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
> index aa8bbb4..77b63e7 100644
> --- a/drivers/gpu/drm/drm_ioc32.c
> +++ b/drivers/gpu/drm/drm_ioc32.c
> @@ -93,7 +93,7 @@ static int compat_drm_version(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	version = compat_alloc_user_space(sizeof(*version));
> -	if (!access_ok(VERIFY_WRITE, version, sizeof(*version)))
> +	if (!version)
>  		return -EFAULT;
>  	if (__put_user(v32.name_len, &version->name_len)
>  	    || __put_user((void __user *)(unsigned long)v32.name,
> @@ -140,7 +140,7 @@ static int compat_drm_getunique(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	u = compat_alloc_user_space(sizeof(*u));
> -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
> +	if (!u)
>  		return -EFAULT;
>  	if (__put_user(uq32.unique_len, &u->unique_len)
>  	    || __put_user((void __user *)(unsigned long)uq32.unique,
> @@ -168,7 +168,7 @@ static int compat_drm_setunique(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	u = compat_alloc_user_space(sizeof(*u));
> -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
> +	if (!u)
>  		return -EFAULT;
>  	if (__put_user(uq32.unique_len, &u->unique_len)
>  	    || __put_user((void __user *)(unsigned long)uq32.unique,
> @@ -200,7 +200,7 @@ static int compat_drm_getmap(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	map = compat_alloc_user_space(sizeof(*map));
> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> +	if (!map)
>  		return -EFAULT;
>  	if (__put_user(idx, &map->offset))
>  		return -EFAULT;
> @@ -237,7 +237,7 @@ static int compat_drm_addmap(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	map = compat_alloc_user_space(sizeof(*map));
> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> +	if (!map)
>  		return -EFAULT;
>  	if (__put_user(m32.offset, &map->offset)
>  	    || __put_user(m32.size, &map->size)
> @@ -277,7 +277,7 @@ static int compat_drm_rmmap(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	map = compat_alloc_user_space(sizeof(*map));
> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> +	if (!map)
>  		return -EFAULT;
>  	if (__put_user((void *)(unsigned long)handle, &map->handle))
>  		return -EFAULT;
> @@ -306,7 +306,7 @@ static int compat_drm_getclient(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	client = compat_alloc_user_space(sizeof(*client));
> -	if (!access_ok(VERIFY_WRITE, client, sizeof(*client)))
> +	if (!client)
>  		return -EFAULT;
>  	if (__put_user(idx, &client->idx))
>  		return -EFAULT;
> @@ -345,7 +345,7 @@ static int compat_drm_getstats(struct file *file, unsigned int cmd,
>  	int i, err;
>  
>  	stats = compat_alloc_user_space(sizeof(*stats));
> -	if (!access_ok(VERIFY_WRITE, stats, sizeof(*stats)))
> +	if (!stats)
>  		return -EFAULT;
>  
>  	err = drm_ioctl(file, DRM_IOCTL_GET_STATS, (unsigned long)stats);
> @@ -382,8 +382,7 @@ static int compat_drm_addbufs(struct file *file, unsigned int cmd,
>  	unsigned long agp_start;
>  
>  	buf = compat_alloc_user_space(sizeof(*buf));
> -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf))
> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp)))
> +	if (!buf || !argp)
>  		return -EFAULT;
>  
>  	if (__copy_in_user(buf, argp, offsetof(drm_buf_desc32_t, agp_start))
> @@ -414,7 +413,7 @@ static int compat_drm_markbufs(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	buf = compat_alloc_user_space(sizeof(*buf));
> -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf)))
> +	if (!buf)
>  		return -EFAULT;
>  
>  	if (__put_user(b32.size, &buf->size)
> @@ -455,7 +454,7 @@ static int compat_drm_infobufs(struct file *file, unsigned int cmd,
>  
>  	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_desc);
>  	request = compat_alloc_user_space(nbytes);
> -	if (!access_ok(VERIFY_WRITE, request, nbytes))
> +	if (!request)
>  		return -EFAULT;
>  	list = (struct drm_buf_desc *) (request + 1);
>  
> @@ -516,7 +515,7 @@ static int compat_drm_mapbufs(struct file *file, unsigned int cmd,
>  		return -EINVAL;
>  	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_pub);
>  	request = compat_alloc_user_space(nbytes);
> -	if (!access_ok(VERIFY_WRITE, request, nbytes))
> +	if (!request)
>  		return -EFAULT;
>  	list = (struct drm_buf_pub *) (request + 1);
>  
> @@ -563,7 +562,7 @@ static int compat_drm_freebufs(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> +	if (!request)
>  		return -EFAULT;
>  	if (__put_user(req32.count, &request->count)
>  	    || __put_user((int __user *)(unsigned long)req32.list,
> @@ -589,7 +588,7 @@ static int compat_drm_setsareactx(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> +	if (!request)
>  		return -EFAULT;
>  	if (__put_user(req32.ctx_id, &request->ctx_id)
>  	    || __put_user((void *)(unsigned long)req32.handle,
> @@ -613,7 +612,7 @@ static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> +	if (!request)
>  		return -EFAULT;
>  	if (__put_user(ctx_id, &request->ctx_id))
>  		return -EFAULT;
> @@ -646,7 +645,7 @@ static int compat_drm_resctx(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	res = compat_alloc_user_space(sizeof(*res));
> -	if (!access_ok(VERIFY_WRITE, res, sizeof(*res)))
> +	if (!res)
>  		return -EFAULT;
>  	if (__put_user(res32.count, &res->count)
>  	    || __put_user((struct drm_ctx __user *) (unsigned long)res32.contexts,
> @@ -689,7 +688,7 @@ static int compat_drm_dma(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	d = compat_alloc_user_space(sizeof(*d));
> -	if (!access_ok(VERIFY_WRITE, d, sizeof(*d)))
> +	if (!d)
>  		return -EFAULT;
>  
>  	if (__put_user(d32.context, &d->context)
> @@ -764,7 +763,7 @@ static int compat_drm_agp_info(struct file *file, unsigned int cmd,
>  	int err;
>  
>  	info = compat_alloc_user_space(sizeof(*info));
> -	if (!access_ok(VERIFY_WRITE, info, sizeof(*info)))
> +	if (!info)
>  		return -EFAULT;
>  
>  	err = drm_ioctl(file, DRM_IOCTL_AGP_INFO, (unsigned long)info);
> @@ -807,7 +806,7 @@ static int compat_drm_agp_alloc(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || __put_user(req32.size, &request->size)
>  	    || __put_user(req32.type, &request->type))
>  		return -EFAULT;
> @@ -834,7 +833,7 @@ static int compat_drm_agp_free(struct file *file, unsigned int cmd,
>  	u32 handle;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || get_user(handle, &argp->handle)
>  	    || __put_user(handle, &request->handle))
>  		return -EFAULT;
> @@ -858,7 +857,7 @@ static int compat_drm_agp_bind(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || __put_user(req32.handle, &request->handle)
>  	    || __put_user(req32.offset, &request->offset))
>  		return -EFAULT;
> @@ -874,7 +873,7 @@ static int compat_drm_agp_unbind(struct file *file, unsigned int cmd,
>  	u32 handle;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || get_user(handle, &argp->handle)
>  	    || __put_user(handle, &request->handle))
>  		return -EFAULT;
> @@ -897,8 +896,7 @@ static int compat_drm_sg_alloc(struct file *file, unsigned int cmd,
>  	unsigned long x;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
> +	if (!request || !argp
>  	    || __get_user(x, &argp->size)
>  	    || __put_user(x, &request->size))
>  		return -EFAULT;
> @@ -923,8 +921,7 @@ static int compat_drm_sg_free(struct file *file, unsigned int cmd,
>  	unsigned long x;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
> +	if (!request || !argp
>  	    || __get_user(x, &argp->handle)
>  	    || __put_user(x << PAGE_SHIFT, &request->handle))
>  		return -EFAULT;
> @@ -952,7 +949,7 @@ static int compat_drm_update_draw(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)) ||
> +	if (!request ||
>  	    __put_user(update32.handle, &request->handle) ||
>  	    __put_user(update32.type, &request->type) ||
>  	    __put_user(update32.num, &request->num) ||
> @@ -994,7 +991,7 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || __put_user(req32.request.type, &request->request.type)
>  	    || __put_user(req32.request.sequence, &request->request.sequence)
>  	    || __put_user(req32.request.signal, &request->request.signal))
> -- 
> 2.1.4
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
Jani Nikula July 2, 2015, 8:10 a.m. UTC | #2
On Wed, 01 Jul 2015, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> wrote:
> The compat ioctl handler ends up calling access_ok() twice: first
> indirectly inside compat_alloc_user_space() and then after returning
> from that function. This patch fixes issue.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
>  drivers/gpu/drm/drm_ioc32.c | 55 +++++++++++++++++++++------------------------
>  1 file changed, 26 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
> index aa8bbb4..77b63e7 100644
> --- a/drivers/gpu/drm/drm_ioc32.c
> +++ b/drivers/gpu/drm/drm_ioc32.c
> @@ -93,7 +93,7 @@ static int compat_drm_version(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	version = compat_alloc_user_space(sizeof(*version));
> -	if (!access_ok(VERIFY_WRITE, version, sizeof(*version)))
> +	if (!version)
>  		return -EFAULT;
>  	if (__put_user(v32.name_len, &version->name_len)
>  	    || __put_user((void __user *)(unsigned long)v32.name,
> @@ -140,7 +140,7 @@ static int compat_drm_getunique(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	u = compat_alloc_user_space(sizeof(*u));
> -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
> +	if (!u)
>  		return -EFAULT;
>  	if (__put_user(uq32.unique_len, &u->unique_len)
>  	    || __put_user((void __user *)(unsigned long)uq32.unique,
> @@ -168,7 +168,7 @@ static int compat_drm_setunique(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	u = compat_alloc_user_space(sizeof(*u));
> -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
> +	if (!u)
>  		return -EFAULT;
>  	if (__put_user(uq32.unique_len, &u->unique_len)
>  	    || __put_user((void __user *)(unsigned long)uq32.unique,
> @@ -200,7 +200,7 @@ static int compat_drm_getmap(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	map = compat_alloc_user_space(sizeof(*map));
> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> +	if (!map)
>  		return -EFAULT;
>  	if (__put_user(idx, &map->offset))
>  		return -EFAULT;
> @@ -237,7 +237,7 @@ static int compat_drm_addmap(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	map = compat_alloc_user_space(sizeof(*map));
> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> +	if (!map)
>  		return -EFAULT;
>  	if (__put_user(m32.offset, &map->offset)
>  	    || __put_user(m32.size, &map->size)
> @@ -277,7 +277,7 @@ static int compat_drm_rmmap(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	map = compat_alloc_user_space(sizeof(*map));
> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> +	if (!map)
>  		return -EFAULT;
>  	if (__put_user((void *)(unsigned long)handle, &map->handle))
>  		return -EFAULT;
> @@ -306,7 +306,7 @@ static int compat_drm_getclient(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	client = compat_alloc_user_space(sizeof(*client));
> -	if (!access_ok(VERIFY_WRITE, client, sizeof(*client)))
> +	if (!client)
>  		return -EFAULT;
>  	if (__put_user(idx, &client->idx))
>  		return -EFAULT;
> @@ -345,7 +345,7 @@ static int compat_drm_getstats(struct file *file, unsigned int cmd,
>  	int i, err;
>  
>  	stats = compat_alloc_user_space(sizeof(*stats));
> -	if (!access_ok(VERIFY_WRITE, stats, sizeof(*stats)))
> +	if (!stats)
>  		return -EFAULT;
>  
>  	err = drm_ioctl(file, DRM_IOCTL_GET_STATS, (unsigned long)stats);
> @@ -382,8 +382,7 @@ static int compat_drm_addbufs(struct file *file, unsigned int cmd,
>  	unsigned long agp_start;
>  
>  	buf = compat_alloc_user_space(sizeof(*buf));
> -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf))
> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp)))
> +	if (!buf || !argp)

The risks of touching old code... who does access_ok on argp now? That
doesn't come from compat_alloc_user_space.

Same pattern repeated below a few times.

BR,
Jani.


>  		return -EFAULT;
>  
>  	if (__copy_in_user(buf, argp, offsetof(drm_buf_desc32_t, agp_start))
> @@ -414,7 +413,7 @@ static int compat_drm_markbufs(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	buf = compat_alloc_user_space(sizeof(*buf));
> -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf)))
> +	if (!buf)
>  		return -EFAULT;
>  
>  	if (__put_user(b32.size, &buf->size)
> @@ -455,7 +454,7 @@ static int compat_drm_infobufs(struct file *file, unsigned int cmd,
>  
>  	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_desc);
>  	request = compat_alloc_user_space(nbytes);
> -	if (!access_ok(VERIFY_WRITE, request, nbytes))
> +	if (!request)
>  		return -EFAULT;
>  	list = (struct drm_buf_desc *) (request + 1);
>  
> @@ -516,7 +515,7 @@ static int compat_drm_mapbufs(struct file *file, unsigned int cmd,
>  		return -EINVAL;
>  	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_pub);
>  	request = compat_alloc_user_space(nbytes);
> -	if (!access_ok(VERIFY_WRITE, request, nbytes))
> +	if (!request)
>  		return -EFAULT;
>  	list = (struct drm_buf_pub *) (request + 1);
>  
> @@ -563,7 +562,7 @@ static int compat_drm_freebufs(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> +	if (!request)
>  		return -EFAULT;
>  	if (__put_user(req32.count, &request->count)
>  	    || __put_user((int __user *)(unsigned long)req32.list,
> @@ -589,7 +588,7 @@ static int compat_drm_setsareactx(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> +	if (!request)
>  		return -EFAULT;
>  	if (__put_user(req32.ctx_id, &request->ctx_id)
>  	    || __put_user((void *)(unsigned long)req32.handle,
> @@ -613,7 +612,7 @@ static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> +	if (!request)
>  		return -EFAULT;
>  	if (__put_user(ctx_id, &request->ctx_id))
>  		return -EFAULT;
> @@ -646,7 +645,7 @@ static int compat_drm_resctx(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	res = compat_alloc_user_space(sizeof(*res));
> -	if (!access_ok(VERIFY_WRITE, res, sizeof(*res)))
> +	if (!res)
>  		return -EFAULT;
>  	if (__put_user(res32.count, &res->count)
>  	    || __put_user((struct drm_ctx __user *) (unsigned long)res32.contexts,
> @@ -689,7 +688,7 @@ static int compat_drm_dma(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	d = compat_alloc_user_space(sizeof(*d));
> -	if (!access_ok(VERIFY_WRITE, d, sizeof(*d)))
> +	if (!d)
>  		return -EFAULT;
>  
>  	if (__put_user(d32.context, &d->context)
> @@ -764,7 +763,7 @@ static int compat_drm_agp_info(struct file *file, unsigned int cmd,
>  	int err;
>  
>  	info = compat_alloc_user_space(sizeof(*info));
> -	if (!access_ok(VERIFY_WRITE, info, sizeof(*info)))
> +	if (!info)
>  		return -EFAULT;
>  
>  	err = drm_ioctl(file, DRM_IOCTL_AGP_INFO, (unsigned long)info);
> @@ -807,7 +806,7 @@ static int compat_drm_agp_alloc(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || __put_user(req32.size, &request->size)
>  	    || __put_user(req32.type, &request->type))
>  		return -EFAULT;
> @@ -834,7 +833,7 @@ static int compat_drm_agp_free(struct file *file, unsigned int cmd,
>  	u32 handle;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || get_user(handle, &argp->handle)
>  	    || __put_user(handle, &request->handle))
>  		return -EFAULT;
> @@ -858,7 +857,7 @@ static int compat_drm_agp_bind(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || __put_user(req32.handle, &request->handle)
>  	    || __put_user(req32.offset, &request->offset))
>  		return -EFAULT;
> @@ -874,7 +873,7 @@ static int compat_drm_agp_unbind(struct file *file, unsigned int cmd,
>  	u32 handle;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || get_user(handle, &argp->handle)
>  	    || __put_user(handle, &request->handle))
>  		return -EFAULT;
> @@ -897,8 +896,7 @@ static int compat_drm_sg_alloc(struct file *file, unsigned int cmd,
>  	unsigned long x;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
> +	if (!request || !argp
>  	    || __get_user(x, &argp->size)
>  	    || __put_user(x, &request->size))
>  		return -EFAULT;
> @@ -923,8 +921,7 @@ static int compat_drm_sg_free(struct file *file, unsigned int cmd,
>  	unsigned long x;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
> +	if (!request || !argp
>  	    || __get_user(x, &argp->handle)
>  	    || __put_user(x << PAGE_SHIFT, &request->handle))
>  		return -EFAULT;
> @@ -952,7 +949,7 @@ static int compat_drm_update_draw(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)) ||
> +	if (!request ||
>  	    __put_user(update32.handle, &request->handle) ||
>  	    __put_user(update32.type, &request->type) ||
>  	    __put_user(update32.num, &request->num) ||
> @@ -994,7 +991,7 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
>  		return -EFAULT;
>  
>  	request = compat_alloc_user_space(sizeof(*request));
> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> +	if (!request
>  	    || __put_user(req32.request.type, &request->request.type)
>  	    || __put_user(req32.request.sequence, &request->request.sequence)
>  	    || __put_user(req32.request.signal, &request->request.signal))
> -- 
> 2.1.4
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
Daniel Vetter July 2, 2015, 2:24 p.m. UTC | #3
On Thu, Jul 02, 2015 at 11:10:06AM +0300, Jani Nikula wrote:
> On Wed, 01 Jul 2015, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> wrote:
> > The compat ioctl handler ends up calling access_ok() twice: first
> > indirectly inside compat_alloc_user_space() and then after returning
> > from that function. This patch fixes issue.
> >
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > ---
> >  drivers/gpu/drm/drm_ioc32.c | 55 +++++++++++++++++++++------------------------
> >  1 file changed, 26 insertions(+), 29 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
> > index aa8bbb4..77b63e7 100644
> > --- a/drivers/gpu/drm/drm_ioc32.c
> > +++ b/drivers/gpu/drm/drm_ioc32.c
> > @@ -93,7 +93,7 @@ static int compat_drm_version(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	version = compat_alloc_user_space(sizeof(*version));
> > -	if (!access_ok(VERIFY_WRITE, version, sizeof(*version)))
> > +	if (!version)
> >  		return -EFAULT;
> >  	if (__put_user(v32.name_len, &version->name_len)
> >  	    || __put_user((void __user *)(unsigned long)v32.name,
> > @@ -140,7 +140,7 @@ static int compat_drm_getunique(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	u = compat_alloc_user_space(sizeof(*u));
> > -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
> > +	if (!u)
> >  		return -EFAULT;
> >  	if (__put_user(uq32.unique_len, &u->unique_len)
> >  	    || __put_user((void __user *)(unsigned long)uq32.unique,
> > @@ -168,7 +168,7 @@ static int compat_drm_setunique(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	u = compat_alloc_user_space(sizeof(*u));
> > -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
> > +	if (!u)
> >  		return -EFAULT;
> >  	if (__put_user(uq32.unique_len, &u->unique_len)
> >  	    || __put_user((void __user *)(unsigned long)uq32.unique,
> > @@ -200,7 +200,7 @@ static int compat_drm_getmap(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	map = compat_alloc_user_space(sizeof(*map));
> > -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> > +	if (!map)
> >  		return -EFAULT;
> >  	if (__put_user(idx, &map->offset))
> >  		return -EFAULT;
> > @@ -237,7 +237,7 @@ static int compat_drm_addmap(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	map = compat_alloc_user_space(sizeof(*map));
> > -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> > +	if (!map)
> >  		return -EFAULT;
> >  	if (__put_user(m32.offset, &map->offset)
> >  	    || __put_user(m32.size, &map->size)
> > @@ -277,7 +277,7 @@ static int compat_drm_rmmap(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	map = compat_alloc_user_space(sizeof(*map));
> > -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
> > +	if (!map)
> >  		return -EFAULT;
> >  	if (__put_user((void *)(unsigned long)handle, &map->handle))
> >  		return -EFAULT;
> > @@ -306,7 +306,7 @@ static int compat_drm_getclient(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	client = compat_alloc_user_space(sizeof(*client));
> > -	if (!access_ok(VERIFY_WRITE, client, sizeof(*client)))
> > +	if (!client)
> >  		return -EFAULT;
> >  	if (__put_user(idx, &client->idx))
> >  		return -EFAULT;
> > @@ -345,7 +345,7 @@ static int compat_drm_getstats(struct file *file, unsigned int cmd,
> >  	int i, err;
> >  
> >  	stats = compat_alloc_user_space(sizeof(*stats));
> > -	if (!access_ok(VERIFY_WRITE, stats, sizeof(*stats)))
> > +	if (!stats)
> >  		return -EFAULT;
> >  
> >  	err = drm_ioctl(file, DRM_IOCTL_GET_STATS, (unsigned long)stats);
> > @@ -382,8 +382,7 @@ static int compat_drm_addbufs(struct file *file, unsigned int cmd,
> >  	unsigned long agp_start;
> >  
> >  	buf = compat_alloc_user_space(sizeof(*buf));
> > -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf))
> > -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp)))
> > +	if (!buf || !argp)
> 
> The risks of touching old code... who does access_ok on argp now? That
> doesn't come from compat_alloc_user_space.
> 
> Same pattern repeated below a few times.

Oops, good catch. Patch dropped again.
-Daniel

> 
> BR,
> Jani.
> 
> 
> >  		return -EFAULT;
> >  
> >  	if (__copy_in_user(buf, argp, offsetof(drm_buf_desc32_t, agp_start))
> > @@ -414,7 +413,7 @@ static int compat_drm_markbufs(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	buf = compat_alloc_user_space(sizeof(*buf));
> > -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf)))
> > +	if (!buf)
> >  		return -EFAULT;
> >  
> >  	if (__put_user(b32.size, &buf->size)
> > @@ -455,7 +454,7 @@ static int compat_drm_infobufs(struct file *file, unsigned int cmd,
> >  
> >  	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_desc);
> >  	request = compat_alloc_user_space(nbytes);
> > -	if (!access_ok(VERIFY_WRITE, request, nbytes))
> > +	if (!request)
> >  		return -EFAULT;
> >  	list = (struct drm_buf_desc *) (request + 1);
> >  
> > @@ -516,7 +515,7 @@ static int compat_drm_mapbufs(struct file *file, unsigned int cmd,
> >  		return -EINVAL;
> >  	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_pub);
> >  	request = compat_alloc_user_space(nbytes);
> > -	if (!access_ok(VERIFY_WRITE, request, nbytes))
> > +	if (!request)
> >  		return -EFAULT;
> >  	list = (struct drm_buf_pub *) (request + 1);
> >  
> > @@ -563,7 +562,7 @@ static int compat_drm_freebufs(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> > +	if (!request)
> >  		return -EFAULT;
> >  	if (__put_user(req32.count, &request->count)
> >  	    || __put_user((int __user *)(unsigned long)req32.list,
> > @@ -589,7 +588,7 @@ static int compat_drm_setsareactx(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> > +	if (!request)
> >  		return -EFAULT;
> >  	if (__put_user(req32.ctx_id, &request->ctx_id)
> >  	    || __put_user((void *)(unsigned long)req32.handle,
> > @@ -613,7 +612,7 @@ static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
> > +	if (!request)
> >  		return -EFAULT;
> >  	if (__put_user(ctx_id, &request->ctx_id))
> >  		return -EFAULT;
> > @@ -646,7 +645,7 @@ static int compat_drm_resctx(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	res = compat_alloc_user_space(sizeof(*res));
> > -	if (!access_ok(VERIFY_WRITE, res, sizeof(*res)))
> > +	if (!res)
> >  		return -EFAULT;
> >  	if (__put_user(res32.count, &res->count)
> >  	    || __put_user((struct drm_ctx __user *) (unsigned long)res32.contexts,
> > @@ -689,7 +688,7 @@ static int compat_drm_dma(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	d = compat_alloc_user_space(sizeof(*d));
> > -	if (!access_ok(VERIFY_WRITE, d, sizeof(*d)))
> > +	if (!d)
> >  		return -EFAULT;
> >  
> >  	if (__put_user(d32.context, &d->context)
> > @@ -764,7 +763,7 @@ static int compat_drm_agp_info(struct file *file, unsigned int cmd,
> >  	int err;
> >  
> >  	info = compat_alloc_user_space(sizeof(*info));
> > -	if (!access_ok(VERIFY_WRITE, info, sizeof(*info)))
> > +	if (!info)
> >  		return -EFAULT;
> >  
> >  	err = drm_ioctl(file, DRM_IOCTL_AGP_INFO, (unsigned long)info);
> > @@ -807,7 +806,7 @@ static int compat_drm_agp_alloc(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> > +	if (!request
> >  	    || __put_user(req32.size, &request->size)
> >  	    || __put_user(req32.type, &request->type))
> >  		return -EFAULT;
> > @@ -834,7 +833,7 @@ static int compat_drm_agp_free(struct file *file, unsigned int cmd,
> >  	u32 handle;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> > +	if (!request
> >  	    || get_user(handle, &argp->handle)
> >  	    || __put_user(handle, &request->handle))
> >  		return -EFAULT;
> > @@ -858,7 +857,7 @@ static int compat_drm_agp_bind(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> > +	if (!request
> >  	    || __put_user(req32.handle, &request->handle)
> >  	    || __put_user(req32.offset, &request->offset))
> >  		return -EFAULT;
> > @@ -874,7 +873,7 @@ static int compat_drm_agp_unbind(struct file *file, unsigned int cmd,
> >  	u32 handle;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> > +	if (!request
> >  	    || get_user(handle, &argp->handle)
> >  	    || __put_user(handle, &request->handle))
> >  		return -EFAULT;
> > @@ -897,8 +896,7 @@ static int compat_drm_sg_alloc(struct file *file, unsigned int cmd,
> >  	unsigned long x;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> > -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
> > +	if (!request || !argp
> >  	    || __get_user(x, &argp->size)
> >  	    || __put_user(x, &request->size))
> >  		return -EFAULT;
> > @@ -923,8 +921,7 @@ static int compat_drm_sg_free(struct file *file, unsigned int cmd,
> >  	unsigned long x;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> > -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
> > +	if (!request || !argp
> >  	    || __get_user(x, &argp->handle)
> >  	    || __put_user(x << PAGE_SHIFT, &request->handle))
> >  		return -EFAULT;
> > @@ -952,7 +949,7 @@ static int compat_drm_update_draw(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)) ||
> > +	if (!request ||
> >  	    __put_user(update32.handle, &request->handle) ||
> >  	    __put_user(update32.type, &request->type) ||
> >  	    __put_user(update32.num, &request->num) ||
> > @@ -994,7 +991,7 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
> >  		return -EFAULT;
> >  
> >  	request = compat_alloc_user_space(sizeof(*request));
> > -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
> > +	if (!request
> >  	    || __put_user(req32.request.type, &request->request.type)
> >  	    || __put_user(req32.request.sequence, &request->request.sequence)
> >  	    || __put_user(req32.request.signal, &request->request.signal))
> > -- 
> > 2.1.4
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
Jarkko Sakkinen July 3, 2015, 10:59 a.m. UTC | #4
On 07/02/2015 10:32 AM, Daniel Vetter wrote:
> On Wed, Jul 01, 2015 at 12:24:37PM +0300, Jarkko Sakkinen wrote:
>> The compat ioctl handler ends up calling access_ok() twice: first
>> indirectly inside compat_alloc_user_space() and then after returning
>> from that function. This patch fixes issue.
>>
>> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Applied to topic/drm-misc, thanks. Btw is this generated with some cocci
> script or not?

Nope. I just bumped into this when working on one yet-to-be-published
driver on a completely different area and was comparing compat ioctl
handlers.

> -Daniel
>
>> ---
>>   drivers/gpu/drm/drm_ioc32.c | 55 +++++++++++++++++++++------------------------
>>   1 file changed, 26 insertions(+), 29 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
>> index aa8bbb4..77b63e7 100644
>> --- a/drivers/gpu/drm/drm_ioc32.c
>> +++ b/drivers/gpu/drm/drm_ioc32.c
>> @@ -93,7 +93,7 @@ static int compat_drm_version(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	version = compat_alloc_user_space(sizeof(*version));
>> -	if (!access_ok(VERIFY_WRITE, version, sizeof(*version)))
>> +	if (!version)
>>   		return -EFAULT;
>>   	if (__put_user(v32.name_len, &version->name_len)
>>   	    || __put_user((void __user *)(unsigned long)v32.name,
>> @@ -140,7 +140,7 @@ static int compat_drm_getunique(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	u = compat_alloc_user_space(sizeof(*u));
>> -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
>> +	if (!u)
>>   		return -EFAULT;
>>   	if (__put_user(uq32.unique_len, &u->unique_len)
>>   	    || __put_user((void __user *)(unsigned long)uq32.unique,
>> @@ -168,7 +168,7 @@ static int compat_drm_setunique(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	u = compat_alloc_user_space(sizeof(*u));
>> -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
>> +	if (!u)
>>   		return -EFAULT;
>>   	if (__put_user(uq32.unique_len, &u->unique_len)
>>   	    || __put_user((void __user *)(unsigned long)uq32.unique,
>> @@ -200,7 +200,7 @@ static int compat_drm_getmap(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	map = compat_alloc_user_space(sizeof(*map));
>> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
>> +	if (!map)
>>   		return -EFAULT;
>>   	if (__put_user(idx, &map->offset))
>>   		return -EFAULT;
>> @@ -237,7 +237,7 @@ static int compat_drm_addmap(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	map = compat_alloc_user_space(sizeof(*map));
>> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
>> +	if (!map)
>>   		return -EFAULT;
>>   	if (__put_user(m32.offset, &map->offset)
>>   	    || __put_user(m32.size, &map->size)
>> @@ -277,7 +277,7 @@ static int compat_drm_rmmap(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	map = compat_alloc_user_space(sizeof(*map));
>> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
>> +	if (!map)
>>   		return -EFAULT;
>>   	if (__put_user((void *)(unsigned long)handle, &map->handle))
>>   		return -EFAULT;
>> @@ -306,7 +306,7 @@ static int compat_drm_getclient(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	client = compat_alloc_user_space(sizeof(*client));
>> -	if (!access_ok(VERIFY_WRITE, client, sizeof(*client)))
>> +	if (!client)
>>   		return -EFAULT;
>>   	if (__put_user(idx, &client->idx))
>>   		return -EFAULT;
>> @@ -345,7 +345,7 @@ static int compat_drm_getstats(struct file *file, unsigned int cmd,
>>   	int i, err;
>>   
>>   	stats = compat_alloc_user_space(sizeof(*stats));
>> -	if (!access_ok(VERIFY_WRITE, stats, sizeof(*stats)))
>> +	if (!stats)
>>   		return -EFAULT;
>>   
>>   	err = drm_ioctl(file, DRM_IOCTL_GET_STATS, (unsigned long)stats);
>> @@ -382,8 +382,7 @@ static int compat_drm_addbufs(struct file *file, unsigned int cmd,
>>   	unsigned long agp_start;
>>   
>>   	buf = compat_alloc_user_space(sizeof(*buf));
>> -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf))
>> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp)))
>> +	if (!buf || !argp)
>>   		return -EFAULT;
>>   
>>   	if (__copy_in_user(buf, argp, offsetof(drm_buf_desc32_t, agp_start))
>> @@ -414,7 +413,7 @@ static int compat_drm_markbufs(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	buf = compat_alloc_user_space(sizeof(*buf));
>> -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf)))
>> +	if (!buf)
>>   		return -EFAULT;
>>   
>>   	if (__put_user(b32.size, &buf->size)
>> @@ -455,7 +454,7 @@ static int compat_drm_infobufs(struct file *file, unsigned int cmd,
>>   
>>   	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_desc);
>>   	request = compat_alloc_user_space(nbytes);
>> -	if (!access_ok(VERIFY_WRITE, request, nbytes))
>> +	if (!request)
>>   		return -EFAULT;
>>   	list = (struct drm_buf_desc *) (request + 1);
>>   
>> @@ -516,7 +515,7 @@ static int compat_drm_mapbufs(struct file *file, unsigned int cmd,
>>   		return -EINVAL;
>>   	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_pub);
>>   	request = compat_alloc_user_space(nbytes);
>> -	if (!access_ok(VERIFY_WRITE, request, nbytes))
>> +	if (!request)
>>   		return -EFAULT;
>>   	list = (struct drm_buf_pub *) (request + 1);
>>   
>> @@ -563,7 +562,7 @@ static int compat_drm_freebufs(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
>> +	if (!request)
>>   		return -EFAULT;
>>   	if (__put_user(req32.count, &request->count)
>>   	    || __put_user((int __user *)(unsigned long)req32.list,
>> @@ -589,7 +588,7 @@ static int compat_drm_setsareactx(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
>> +	if (!request)
>>   		return -EFAULT;
>>   	if (__put_user(req32.ctx_id, &request->ctx_id)
>>   	    || __put_user((void *)(unsigned long)req32.handle,
>> @@ -613,7 +612,7 @@ static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
>> +	if (!request)
>>   		return -EFAULT;
>>   	if (__put_user(ctx_id, &request->ctx_id))
>>   		return -EFAULT;
>> @@ -646,7 +645,7 @@ static int compat_drm_resctx(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	res = compat_alloc_user_space(sizeof(*res));
>> -	if (!access_ok(VERIFY_WRITE, res, sizeof(*res)))
>> +	if (!res)
>>   		return -EFAULT;
>>   	if (__put_user(res32.count, &res->count)
>>   	    || __put_user((struct drm_ctx __user *) (unsigned long)res32.contexts,
>> @@ -689,7 +688,7 @@ static int compat_drm_dma(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	d = compat_alloc_user_space(sizeof(*d));
>> -	if (!access_ok(VERIFY_WRITE, d, sizeof(*d)))
>> +	if (!d)
>>   		return -EFAULT;
>>   
>>   	if (__put_user(d32.context, &d->context)
>> @@ -764,7 +763,7 @@ static int compat_drm_agp_info(struct file *file, unsigned int cmd,
>>   	int err;
>>   
>>   	info = compat_alloc_user_space(sizeof(*info));
>> -	if (!access_ok(VERIFY_WRITE, info, sizeof(*info)))
>> +	if (!info)
>>   		return -EFAULT;
>>   
>>   	err = drm_ioctl(file, DRM_IOCTL_AGP_INFO, (unsigned long)info);
>> @@ -807,7 +806,7 @@ static int compat_drm_agp_alloc(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || __put_user(req32.size, &request->size)
>>   	    || __put_user(req32.type, &request->type))
>>   		return -EFAULT;
>> @@ -834,7 +833,7 @@ static int compat_drm_agp_free(struct file *file, unsigned int cmd,
>>   	u32 handle;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || get_user(handle, &argp->handle)
>>   	    || __put_user(handle, &request->handle))
>>   		return -EFAULT;
>> @@ -858,7 +857,7 @@ static int compat_drm_agp_bind(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || __put_user(req32.handle, &request->handle)
>>   	    || __put_user(req32.offset, &request->offset))
>>   		return -EFAULT;
>> @@ -874,7 +873,7 @@ static int compat_drm_agp_unbind(struct file *file, unsigned int cmd,
>>   	u32 handle;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || get_user(handle, &argp->handle)
>>   	    || __put_user(handle, &request->handle))
>>   		return -EFAULT;
>> @@ -897,8 +896,7 @@ static int compat_drm_sg_alloc(struct file *file, unsigned int cmd,
>>   	unsigned long x;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
>> +	if (!request || !argp
>>   	    || __get_user(x, &argp->size)
>>   	    || __put_user(x, &request->size))
>>   		return -EFAULT;
>> @@ -923,8 +921,7 @@ static int compat_drm_sg_free(struct file *file, unsigned int cmd,
>>   	unsigned long x;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
>> +	if (!request || !argp
>>   	    || __get_user(x, &argp->handle)
>>   	    || __put_user(x << PAGE_SHIFT, &request->handle))
>>   		return -EFAULT;
>> @@ -952,7 +949,7 @@ static int compat_drm_update_draw(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)) ||
>> +	if (!request ||
>>   	    __put_user(update32.handle, &request->handle) ||
>>   	    __put_user(update32.type, &request->type) ||
>>   	    __put_user(update32.num, &request->num) ||
>> @@ -994,7 +991,7 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || __put_user(req32.request.type, &request->request.type)
>>   	    || __put_user(req32.request.sequence, &request->request.sequence)
>>   	    || __put_user(req32.request.signal, &request->request.signal))
>> -- 
>> 2.1.4
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
/Jarkko
Jarkko Sakkinen July 3, 2015, 11:03 a.m. UTC | #5
On 07/02/2015 11:10 AM, Jani Nikula wrote:
> On Wed, 01 Jul 2015, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> wrote:
>> The compat ioctl handler ends up calling access_ok() twice: first
>> indirectly inside compat_alloc_user_space() and then after returning
>> from that function. This patch fixes issue.
>>
>> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
>> ---
>>   drivers/gpu/drm/drm_ioc32.c | 55 +++++++++++++++++++++------------------------
>>   1 file changed, 26 insertions(+), 29 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
>> index aa8bbb4..77b63e7 100644
>> --- a/drivers/gpu/drm/drm_ioc32.c
>> +++ b/drivers/gpu/drm/drm_ioc32.c
>> @@ -93,7 +93,7 @@ static int compat_drm_version(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	version = compat_alloc_user_space(sizeof(*version));
>> -	if (!access_ok(VERIFY_WRITE, version, sizeof(*version)))
>> +	if (!version)
>>   		return -EFAULT;
>>   	if (__put_user(v32.name_len, &version->name_len)
>>   	    || __put_user((void __user *)(unsigned long)v32.name,
>> @@ -140,7 +140,7 @@ static int compat_drm_getunique(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	u = compat_alloc_user_space(sizeof(*u));
>> -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
>> +	if (!u)
>>   		return -EFAULT;
>>   	if (__put_user(uq32.unique_len, &u->unique_len)
>>   	    || __put_user((void __user *)(unsigned long)uq32.unique,
>> @@ -168,7 +168,7 @@ static int compat_drm_setunique(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	u = compat_alloc_user_space(sizeof(*u));
>> -	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
>> +	if (!u)
>>   		return -EFAULT;
>>   	if (__put_user(uq32.unique_len, &u->unique_len)
>>   	    || __put_user((void __user *)(unsigned long)uq32.unique,
>> @@ -200,7 +200,7 @@ static int compat_drm_getmap(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	map = compat_alloc_user_space(sizeof(*map));
>> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
>> +	if (!map)
>>   		return -EFAULT;
>>   	if (__put_user(idx, &map->offset))
>>   		return -EFAULT;
>> @@ -237,7 +237,7 @@ static int compat_drm_addmap(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	map = compat_alloc_user_space(sizeof(*map));
>> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
>> +	if (!map)
>>   		return -EFAULT;
>>   	if (__put_user(m32.offset, &map->offset)
>>   	    || __put_user(m32.size, &map->size)
>> @@ -277,7 +277,7 @@ static int compat_drm_rmmap(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	map = compat_alloc_user_space(sizeof(*map));
>> -	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
>> +	if (!map)
>>   		return -EFAULT;
>>   	if (__put_user((void *)(unsigned long)handle, &map->handle))
>>   		return -EFAULT;
>> @@ -306,7 +306,7 @@ static int compat_drm_getclient(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	client = compat_alloc_user_space(sizeof(*client));
>> -	if (!access_ok(VERIFY_WRITE, client, sizeof(*client)))
>> +	if (!client)
>>   		return -EFAULT;
>>   	if (__put_user(idx, &client->idx))
>>   		return -EFAULT;
>> @@ -345,7 +345,7 @@ static int compat_drm_getstats(struct file *file, unsigned int cmd,
>>   	int i, err;
>>   
>>   	stats = compat_alloc_user_space(sizeof(*stats));
>> -	if (!access_ok(VERIFY_WRITE, stats, sizeof(*stats)))
>> +	if (!stats)
>>   		return -EFAULT;
>>   
>>   	err = drm_ioctl(file, DRM_IOCTL_GET_STATS, (unsigned long)stats);
>> @@ -382,8 +382,7 @@ static int compat_drm_addbufs(struct file *file, unsigned int cmd,
>>   	unsigned long agp_start;
>>   
>>   	buf = compat_alloc_user_space(sizeof(*buf));
>> -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf))
>> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp)))
>> +	if (!buf || !argp)
> The risks of touching old code... who does access_ok on argp now? That
> doesn't come from compat_alloc_user_space.
>
> Same pattern repeated below a few times.
Right. Thanks and sorry about sloppiness. I'll update the patch.

>
> BR,
> Jani.
>
>
>>   		return -EFAULT;
>>   
>>   	if (__copy_in_user(buf, argp, offsetof(drm_buf_desc32_t, agp_start))
>> @@ -414,7 +413,7 @@ static int compat_drm_markbufs(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	buf = compat_alloc_user_space(sizeof(*buf));
>> -	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf)))
>> +	if (!buf)
>>   		return -EFAULT;
>>   
>>   	if (__put_user(b32.size, &buf->size)
>> @@ -455,7 +454,7 @@ static int compat_drm_infobufs(struct file *file, unsigned int cmd,
>>   
>>   	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_desc);
>>   	request = compat_alloc_user_space(nbytes);
>> -	if (!access_ok(VERIFY_WRITE, request, nbytes))
>> +	if (!request)
>>   		return -EFAULT;
>>   	list = (struct drm_buf_desc *) (request + 1);
>>   
>> @@ -516,7 +515,7 @@ static int compat_drm_mapbufs(struct file *file, unsigned int cmd,
>>   		return -EINVAL;
>>   	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_pub);
>>   	request = compat_alloc_user_space(nbytes);
>> -	if (!access_ok(VERIFY_WRITE, request, nbytes))
>> +	if (!request)
>>   		return -EFAULT;
>>   	list = (struct drm_buf_pub *) (request + 1);
>>   
>> @@ -563,7 +562,7 @@ static int compat_drm_freebufs(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
>> +	if (!request)
>>   		return -EFAULT;
>>   	if (__put_user(req32.count, &request->count)
>>   	    || __put_user((int __user *)(unsigned long)req32.list,
>> @@ -589,7 +588,7 @@ static int compat_drm_setsareactx(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
>> +	if (!request)
>>   		return -EFAULT;
>>   	if (__put_user(req32.ctx_id, &request->ctx_id)
>>   	    || __put_user((void *)(unsigned long)req32.handle,
>> @@ -613,7 +612,7 @@ static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
>> +	if (!request)
>>   		return -EFAULT;
>>   	if (__put_user(ctx_id, &request->ctx_id))
>>   		return -EFAULT;
>> @@ -646,7 +645,7 @@ static int compat_drm_resctx(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	res = compat_alloc_user_space(sizeof(*res));
>> -	if (!access_ok(VERIFY_WRITE, res, sizeof(*res)))
>> +	if (!res)
>>   		return -EFAULT;
>>   	if (__put_user(res32.count, &res->count)
>>   	    || __put_user((struct drm_ctx __user *) (unsigned long)res32.contexts,
>> @@ -689,7 +688,7 @@ static int compat_drm_dma(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	d = compat_alloc_user_space(sizeof(*d));
>> -	if (!access_ok(VERIFY_WRITE, d, sizeof(*d)))
>> +	if (!d)
>>   		return -EFAULT;
>>   
>>   	if (__put_user(d32.context, &d->context)
>> @@ -764,7 +763,7 @@ static int compat_drm_agp_info(struct file *file, unsigned int cmd,
>>   	int err;
>>   
>>   	info = compat_alloc_user_space(sizeof(*info));
>> -	if (!access_ok(VERIFY_WRITE, info, sizeof(*info)))
>> +	if (!info)
>>   		return -EFAULT;
>>   
>>   	err = drm_ioctl(file, DRM_IOCTL_AGP_INFO, (unsigned long)info);
>> @@ -807,7 +806,7 @@ static int compat_drm_agp_alloc(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || __put_user(req32.size, &request->size)
>>   	    || __put_user(req32.type, &request->type))
>>   		return -EFAULT;
>> @@ -834,7 +833,7 @@ static int compat_drm_agp_free(struct file *file, unsigned int cmd,
>>   	u32 handle;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || get_user(handle, &argp->handle)
>>   	    || __put_user(handle, &request->handle))
>>   		return -EFAULT;
>> @@ -858,7 +857,7 @@ static int compat_drm_agp_bind(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || __put_user(req32.handle, &request->handle)
>>   	    || __put_user(req32.offset, &request->offset))
>>   		return -EFAULT;
>> @@ -874,7 +873,7 @@ static int compat_drm_agp_unbind(struct file *file, unsigned int cmd,
>>   	u32 handle;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || get_user(handle, &argp->handle)
>>   	    || __put_user(handle, &request->handle))
>>   		return -EFAULT;
>> @@ -897,8 +896,7 @@ static int compat_drm_sg_alloc(struct file *file, unsigned int cmd,
>>   	unsigned long x;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
>> +	if (!request || !argp
>>   	    || __get_user(x, &argp->size)
>>   	    || __put_user(x, &request->size))
>>   		return -EFAULT;
>> @@ -923,8 +921,7 @@ static int compat_drm_sg_free(struct file *file, unsigned int cmd,
>>   	unsigned long x;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> -	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
>> +	if (!request || !argp
>>   	    || __get_user(x, &argp->handle)
>>   	    || __put_user(x << PAGE_SHIFT, &request->handle))
>>   		return -EFAULT;
>> @@ -952,7 +949,7 @@ static int compat_drm_update_draw(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)) ||
>> +	if (!request ||
>>   	    __put_user(update32.handle, &request->handle) ||
>>   	    __put_user(update32.type, &request->type) ||
>>   	    __put_user(update32.num, &request->num) ||
>> @@ -994,7 +991,7 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
>>   		return -EFAULT;
>>   
>>   	request = compat_alloc_user_space(sizeof(*request));
>> -	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
>> +	if (!request
>>   	    || __put_user(req32.request.type, &request->request.type)
>>   	    || __put_user(req32.request.sequence, &request->request.sequence)
>>   	    || __put_user(req32.request.signal, &request->request.signal))
>> -- 
>> 2.1.4
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel

/Jarkko
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
index aa8bbb4..77b63e7 100644
--- a/drivers/gpu/drm/drm_ioc32.c
+++ b/drivers/gpu/drm/drm_ioc32.c
@@ -93,7 +93,7 @@  static int compat_drm_version(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	version = compat_alloc_user_space(sizeof(*version));
-	if (!access_ok(VERIFY_WRITE, version, sizeof(*version)))
+	if (!version)
 		return -EFAULT;
 	if (__put_user(v32.name_len, &version->name_len)
 	    || __put_user((void __user *)(unsigned long)v32.name,
@@ -140,7 +140,7 @@  static int compat_drm_getunique(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	u = compat_alloc_user_space(sizeof(*u));
-	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
+	if (!u)
 		return -EFAULT;
 	if (__put_user(uq32.unique_len, &u->unique_len)
 	    || __put_user((void __user *)(unsigned long)uq32.unique,
@@ -168,7 +168,7 @@  static int compat_drm_setunique(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	u = compat_alloc_user_space(sizeof(*u));
-	if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
+	if (!u)
 		return -EFAULT;
 	if (__put_user(uq32.unique_len, &u->unique_len)
 	    || __put_user((void __user *)(unsigned long)uq32.unique,
@@ -200,7 +200,7 @@  static int compat_drm_getmap(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	map = compat_alloc_user_space(sizeof(*map));
-	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
+	if (!map)
 		return -EFAULT;
 	if (__put_user(idx, &map->offset))
 		return -EFAULT;
@@ -237,7 +237,7 @@  static int compat_drm_addmap(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	map = compat_alloc_user_space(sizeof(*map));
-	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
+	if (!map)
 		return -EFAULT;
 	if (__put_user(m32.offset, &map->offset)
 	    || __put_user(m32.size, &map->size)
@@ -277,7 +277,7 @@  static int compat_drm_rmmap(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	map = compat_alloc_user_space(sizeof(*map));
-	if (!access_ok(VERIFY_WRITE, map, sizeof(*map)))
+	if (!map)
 		return -EFAULT;
 	if (__put_user((void *)(unsigned long)handle, &map->handle))
 		return -EFAULT;
@@ -306,7 +306,7 @@  static int compat_drm_getclient(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	client = compat_alloc_user_space(sizeof(*client));
-	if (!access_ok(VERIFY_WRITE, client, sizeof(*client)))
+	if (!client)
 		return -EFAULT;
 	if (__put_user(idx, &client->idx))
 		return -EFAULT;
@@ -345,7 +345,7 @@  static int compat_drm_getstats(struct file *file, unsigned int cmd,
 	int i, err;
 
 	stats = compat_alloc_user_space(sizeof(*stats));
-	if (!access_ok(VERIFY_WRITE, stats, sizeof(*stats)))
+	if (!stats)
 		return -EFAULT;
 
 	err = drm_ioctl(file, DRM_IOCTL_GET_STATS, (unsigned long)stats);
@@ -382,8 +382,7 @@  static int compat_drm_addbufs(struct file *file, unsigned int cmd,
 	unsigned long agp_start;
 
 	buf = compat_alloc_user_space(sizeof(*buf));
-	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf))
-	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp)))
+	if (!buf || !argp)
 		return -EFAULT;
 
 	if (__copy_in_user(buf, argp, offsetof(drm_buf_desc32_t, agp_start))
@@ -414,7 +413,7 @@  static int compat_drm_markbufs(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	buf = compat_alloc_user_space(sizeof(*buf));
-	if (!access_ok(VERIFY_WRITE, buf, sizeof(*buf)))
+	if (!buf)
 		return -EFAULT;
 
 	if (__put_user(b32.size, &buf->size)
@@ -455,7 +454,7 @@  static int compat_drm_infobufs(struct file *file, unsigned int cmd,
 
 	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_desc);
 	request = compat_alloc_user_space(nbytes);
-	if (!access_ok(VERIFY_WRITE, request, nbytes))
+	if (!request)
 		return -EFAULT;
 	list = (struct drm_buf_desc *) (request + 1);
 
@@ -516,7 +515,7 @@  static int compat_drm_mapbufs(struct file *file, unsigned int cmd,
 		return -EINVAL;
 	nbytes = sizeof(*request) + count * sizeof(struct drm_buf_pub);
 	request = compat_alloc_user_space(nbytes);
-	if (!access_ok(VERIFY_WRITE, request, nbytes))
+	if (!request)
 		return -EFAULT;
 	list = (struct drm_buf_pub *) (request + 1);
 
@@ -563,7 +562,7 @@  static int compat_drm_freebufs(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
+	if (!request)
 		return -EFAULT;
 	if (__put_user(req32.count, &request->count)
 	    || __put_user((int __user *)(unsigned long)req32.list,
@@ -589,7 +588,7 @@  static int compat_drm_setsareactx(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
+	if (!request)
 		return -EFAULT;
 	if (__put_user(req32.ctx_id, &request->ctx_id)
 	    || __put_user((void *)(unsigned long)req32.handle,
@@ -613,7 +612,7 @@  static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)))
+	if (!request)
 		return -EFAULT;
 	if (__put_user(ctx_id, &request->ctx_id))
 		return -EFAULT;
@@ -646,7 +645,7 @@  static int compat_drm_resctx(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	res = compat_alloc_user_space(sizeof(*res));
-	if (!access_ok(VERIFY_WRITE, res, sizeof(*res)))
+	if (!res)
 		return -EFAULT;
 	if (__put_user(res32.count, &res->count)
 	    || __put_user((struct drm_ctx __user *) (unsigned long)res32.contexts,
@@ -689,7 +688,7 @@  static int compat_drm_dma(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	d = compat_alloc_user_space(sizeof(*d));
-	if (!access_ok(VERIFY_WRITE, d, sizeof(*d)))
+	if (!d)
 		return -EFAULT;
 
 	if (__put_user(d32.context, &d->context)
@@ -764,7 +763,7 @@  static int compat_drm_agp_info(struct file *file, unsigned int cmd,
 	int err;
 
 	info = compat_alloc_user_space(sizeof(*info));
-	if (!access_ok(VERIFY_WRITE, info, sizeof(*info)))
+	if (!info)
 		return -EFAULT;
 
 	err = drm_ioctl(file, DRM_IOCTL_AGP_INFO, (unsigned long)info);
@@ -807,7 +806,7 @@  static int compat_drm_agp_alloc(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	if (!request
 	    || __put_user(req32.size, &request->size)
 	    || __put_user(req32.type, &request->type))
 		return -EFAULT;
@@ -834,7 +833,7 @@  static int compat_drm_agp_free(struct file *file, unsigned int cmd,
 	u32 handle;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	if (!request
 	    || get_user(handle, &argp->handle)
 	    || __put_user(handle, &request->handle))
 		return -EFAULT;
@@ -858,7 +857,7 @@  static int compat_drm_agp_bind(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	if (!request
 	    || __put_user(req32.handle, &request->handle)
 	    || __put_user(req32.offset, &request->offset))
 		return -EFAULT;
@@ -874,7 +873,7 @@  static int compat_drm_agp_unbind(struct file *file, unsigned int cmd,
 	u32 handle;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	if (!request
 	    || get_user(handle, &argp->handle)
 	    || __put_user(handle, &request->handle))
 		return -EFAULT;
@@ -897,8 +896,7 @@  static int compat_drm_sg_alloc(struct file *file, unsigned int cmd,
 	unsigned long x;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
-	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
+	if (!request || !argp
 	    || __get_user(x, &argp->size)
 	    || __put_user(x, &request->size))
 		return -EFAULT;
@@ -923,8 +921,7 @@  static int compat_drm_sg_free(struct file *file, unsigned int cmd,
 	unsigned long x;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
-	    || !access_ok(VERIFY_WRITE, argp, sizeof(*argp))
+	if (!request || !argp
 	    || __get_user(x, &argp->handle)
 	    || __put_user(x << PAGE_SHIFT, &request->handle))
 		return -EFAULT;
@@ -952,7 +949,7 @@  static int compat_drm_update_draw(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request)) ||
+	if (!request ||
 	    __put_user(update32.handle, &request->handle) ||
 	    __put_user(update32.type, &request->type) ||
 	    __put_user(update32.num, &request->num) ||
@@ -994,7 +991,7 @@  static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
 		return -EFAULT;
 
 	request = compat_alloc_user_space(sizeof(*request));
-	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	if (!request
 	    || __put_user(req32.request.type, &request->request.type)
 	    || __put_user(req32.request.sequence, &request->request.sequence)
 	    || __put_user(req32.request.signal, &request->request.signal))