diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-24 17:42:51 +0100 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2026-04-02 08:24:55 +0200 |
| commit | f8995c2df519f382525ca4bc90553ad2ec611067 (patch) | |
| tree | 7ce3aba11ac7b8316ce80eb1c99e8a9593698841 | |
| parent | 5e77923a3eb39cce91bf08ed7670f816bf86d4af (diff) | |
drm/ioc32: stop speculation on the drm_compat_ioctl path
The drm compat ioctl path takes a user controlled pointer, and then
dereferences it into a table of function pointers, the signature method
of spectre problems. Fix this up by calling array_index_nospec() on the
index to the function pointer list.
Fixes: 505b5240329b ("drm/ioctl: Fix Spectre v1 vulnerabilities")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Simona Vetter <simona@ffwll.ch>
Cc: stable <stable@kernel.org>
Assisted-by: gkh_clanker_2000
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Simona Vetter <simona@ffwll.ch>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/2026032451-playing-rummage-8fa2@gregkh
| -rw-r--r-- | drivers/gpu/drm/drm_ioc32.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c index e6b5b06de148..f3e40d1e6098 100644 --- a/drivers/gpu/drm/drm_ioc32.c +++ b/drivers/gpu/drm/drm_ioc32.c @@ -28,6 +28,7 @@ * IN THE SOFTWARE. */ #include <linux/compat.h> +#include <linux/nospec.h> #include <linux/ratelimit.h> #include <linux/export.h> @@ -374,6 +375,7 @@ long drm_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (nr >= ARRAY_SIZE(drm_compat_ioctls)) return drm_ioctl(filp, cmd, arg); + nr = array_index_nospec(nr, ARRAY_SIZE(drm_compat_ioctls)); fn = drm_compat_ioctls[nr].fn; if (!fn) return drm_ioctl(filp, cmd, arg); |