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authorMatthew Wilcox <willy@infradead.org>2019-02-14 11:03:48 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-02-20 10:29:15 +0100
commiteee667bf128011f70d3ad350784dfa77d7050661 (patch)
parente161e0ef3bbb2ffacd38bdc12c17d4ee6d764cb4 (diff)
drm: Use array_size() when creating lease
commit 69ef943dbc14b21987c79f8399ffea08f9a1b446 upstream. Passing an object_count of sufficient size will make object_count * 4 wrap around to be very small, then a later function will happily iterate off the end of the object_ids array. Using array_size() will saturate at SIZE_MAX, the kmalloc() will fail and we'll return an -ENOMEM to the norty userspace. Fixes: 62884cd386b8 ("drm: Add four ioctls for managing drm mode object leases [v7]") Signed-off-by: Matthew Wilcox <willy@infradead.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: <stable@vger.kernel.org> # v4.15+ Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
index c61680ad962d..6e59789e3316 100644
--- a/drivers/gpu/drm/drm_lease.c
+++ b/drivers/gpu/drm/drm_lease.c
@@ -521,7 +521,8 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
object_count = cl->object_count;
- object_ids = memdup_user(u64_to_user_ptr(cl->object_ids), object_count * sizeof(__u32));
+ object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
+ array_size(object_count, sizeof(__u32)));
if (IS_ERR(object_ids))
return PTR_ERR(object_ids);