| Message ID | 20240710231555.work.406-kees@kernel.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 5ac86f0ed04bce41242167ffa12ad92038788a95 |
| Headers | show |
| Series | virt: vbox: struct vmmdev_hgcm_pagelist: Replace 1-element array with flexible array | expand |
On 10/07/24 17:15, Kees Cook wrote: > 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] > Signed-off-by: Kees Cook <kees@kernel.org> > --- > Cc: Hans de Goede <hdegoede@redhat.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> > Cc: linux-hardening@vger.kernel.org Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks -- Gustavo > --- > include/uapi/linux/vbox_vmmdev_types.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > 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); >
On Wed, 10 Jul 2024 16:15:55 -0700, Kees Cook wrote: > 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. > > [...] Applied to for-next/hardening, thanks! [1/1] virt: vbox: struct vmmdev_hgcm_pagelist: Replace 1-element array with flexible array https://git.kernel.org/kees/c/5ac86f0ed04b Take care,
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);
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] Signed-off-by: Kees Cook <kees@kernel.org> --- Cc: Hans de Goede <hdegoede@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> Cc: linux-hardening@vger.kernel.org --- include/uapi/linux/vbox_vmmdev_types.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)