From 2acb20ebfbdec80b432da19809e76fff32dfae04 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 4 Dec 2019 16:52:37 -0800 Subject: [PATCH] drm: limit to INT_MAX in create_blob ioctl [ Upstream commit 5bf8bec3f4ce044a223c40cbce92590d938f0e9c ] The hardened usercpy code is too paranoid ever since commit 6a30afa8c1fb ("uaccess: disallow > INT_MAX copy sizes") Code itself should have been fine as-is. Link: http://lkml.kernel.org/r/20191106164755.31478-1-daniel.vetter@ffwll.ch Signed-off-by: Daniel Vetter Reported-by: syzbot+fb77e97ebf0612ee6914@syzkaller.appspotmail.com Fixes: 6a30afa8c1fb ("uaccess: disallow > INT_MAX copy sizes") Cc: Kees Cook Cc: Alexander Viro Cc: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_property.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_property.c b/drivers/gpu/drm/drm_property.c index 78e630771214..9decd981d94e 100644 --- a/drivers/gpu/drm/drm_property.c +++ b/drivers/gpu/drm/drm_property.c @@ -540,7 +540,7 @@ drm_property_create_blob(struct drm_device *dev, size_t length, struct drm_property_blob *blob; int ret; - if (!length || length > ULONG_MAX - sizeof(struct drm_property_blob)) + if (!length || length > INT_MAX - sizeof(struct drm_property_blob)) return ERR_PTR(-EINVAL); blob = kvzalloc(sizeof(struct drm_property_blob)+length, GFP_KERNEL); -- 2.20.1