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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2021-02-22 11:06:43 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2021-02-26 14:45:56 +0100 |
| commit | e926c474ebee404441c838d18224cd6f246a71b7 (patch) | |
| tree | 102583238d5d982cf8b0ca8501455352cedd51fc /drivers/gpu/drm/drm_ioc32.c | |
| parent | 19bafac4f56f42c499e7343d884b7878204652d3 (diff) | |
| download | lwn-e926c474ebee404441c838d18224cd6f246a71b7.tar.gz lwn-e926c474ebee404441c838d18224cd6f246a71b7.zip | |
drm/compat: Clear bounce structures
Some of them have gaps, or fields we don't clear. Native ioctl code
does full copies plus zero-extends on size mismatch, so nothing can
leak. But compat is more hand-rolled so need to be careful.
None of these matter for performance, so just memset.
Also I didn't fix up the CONFIG_DRM_LEGACY or CONFIG_DRM_AGP ioctl, those
are security holes anyway.
Acked-by: Maxime Ripard <mripard@kernel.org>
Reported-by: syzbot+620cf21140fc7e772a5d@syzkaller.appspotmail.com # vblank ioctl
Cc: syzbot+620cf21140fc7e772a5d@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210222100643.400935-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu/drm/drm_ioc32.c')
| -rw-r--r-- | drivers/gpu/drm/drm_ioc32.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c index f86448ab1fe0..dc734d4828a1 100644 --- a/drivers/gpu/drm/drm_ioc32.c +++ b/drivers/gpu/drm/drm_ioc32.c @@ -99,6 +99,8 @@ static int compat_drm_version(struct file *file, unsigned int cmd, if (copy_from_user(&v32, (void __user *)arg, sizeof(v32))) return -EFAULT; + memset(&v, 0, sizeof(v)); + v = (struct drm_version) { .name_len = v32.name_len, .name = compat_ptr(v32.name), @@ -137,6 +139,9 @@ static int compat_drm_getunique(struct file *file, unsigned int cmd, if (copy_from_user(&uq32, (void __user *)arg, sizeof(uq32))) return -EFAULT; + + memset(&uq, 0, sizeof(uq)); + uq = (struct drm_unique){ .unique_len = uq32.unique_len, .unique = compat_ptr(uq32.unique), @@ -265,6 +270,8 @@ static int compat_drm_getclient(struct file *file, unsigned int cmd, if (copy_from_user(&c32, argp, sizeof(c32))) return -EFAULT; + memset(&client, 0, sizeof(client)); + client.idx = c32.idx; err = drm_ioctl_kernel(file, drm_getclient, &client, 0); @@ -852,6 +859,8 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd, if (copy_from_user(&req32, argp, sizeof(req32))) return -EFAULT; + memset(&req, 0, sizeof(req)); + req.request.type = req32.request.type; req.request.sequence = req32.request.sequence; req.request.signal = req32.request.signal; @@ -889,6 +898,8 @@ static int compat_drm_mode_addfb2(struct file *file, unsigned int cmd, struct drm_mode_fb_cmd2 req64; int err; + memset(&req64, 0, sizeof(req64)); + if (copy_from_user(&req64, argp, offsetof(drm_mode_fb_cmd232_t, modifier))) return -EFAULT; |