lkml.org 
[lkml]   [2015]   [Jul]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH] drm: remove redundant code form drm_ioc32.c
    Date
    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

    --
    Jani Nikula, Intel Open Source Technology Center


    \
     
     \ /
      Last update: 2015-07-02 10:41    [W:3.129 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site