From: Kees Cook Date: Wed, 10 Jul 2024 23:15:55 +0000 (-0700) Subject: virt: vbox: struct vmmdev_hgcm_pagelist: Replace 1-element array with flexible array X-Git-Tag: v6.12-rc1~151^2~6 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=5ac86f0ed04bce41242167ffa12ad92038788a95;p=linux-block.git virt: vbox: struct vmmdev_hgcm_pagelist: Replace 1-element array with flexible array Replace the deprecated[1] use of a 1-element array in struct vmmdev_hgcm_pagelist with a modern flexible array. As this is UAPI, we cannot trivially change the size of the struct, so use a union to retain the old first element's size, but switch "pages" to a flexible array. No binary differences are present after this conversion. Link: https://github.com/KSPP/linux/issues/79 [1] Reviewed-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20240710231555.work.406-kees@kernel.org Signed-off-by: Kees Cook --- diff --git a/include/uapi/linux/vbox_vmmdev_types.h b/include/uapi/linux/vbox_vmmdev_types.h index f8a8d6b3c521..6073858d52a2 100644 --- a/include/uapi/linux/vbox_vmmdev_types.h +++ b/include/uapi/linux/vbox_vmmdev_types.h @@ -282,7 +282,10 @@ struct vmmdev_hgcm_pagelist { __u32 flags; /** VMMDEV_HGCM_F_PARM_*. */ __u16 offset_first_page; /** Data offset in the first page. */ __u16 page_count; /** Number of pages. */ - __u64 pages[1]; /** Page addresses. */ + union { + __u64 unused; /** Deprecated place-holder for first "pages" entry. */ + __DECLARE_FLEX_ARRAY(__u64, pages); /** Page addresses. */ + }; }; VMMDEV_ASSERT_SIZE(vmmdev_hgcm_pagelist, 4 + 2 + 2 + 8);