| Message ID | 20230720151458.never.673-kees@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vboxsf: Use flexible arrays for trailing string member | expand |
Hi Kees, Larry, On 7/20/23 17:15, Kees Cook wrote: > The declaration of struct shfl_string used trailing fake flexible arrays > for the string member. This was tripping FORTIFY_SOURCE since commit > df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3"). Replace the > utf8 and utf16 members with actual flexible arrays, drop the unused ucs2 > member, and retriain a 2 byte padding to keep the structure size the same. > > Reported-by: Larry Finger <Larry.Finger@lwfinger.net> > Closes: https://lore.kernel.org/lkml/ab3a70e9-60ed-0f13-e3d4-8866eaccc8c1@lwfinger.net/ > Tested-by: Larry Finger <Larry.Finger@lwfinger.net> > Signed-off-by: Kees Cook <keescook@chromium.org> Kees, Larry thank you for fixing this while I was on vacation. The patch looks good to me: Reviewed-by: Hans de Goede <hdegoede@redhat.com> Kees, I'm the vboxsf maintainer and it would be easiest for me if you can include this in a future 6.5 fixes pull-request to Linus if that is possible ? Regards, Hans > --- > fs/vboxsf/shfl_hostintf.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/fs/vboxsf/shfl_hostintf.h b/fs/vboxsf/shfl_hostintf.h > index aca829062c12..069a019c9247 100644 > --- a/fs/vboxsf/shfl_hostintf.h > +++ b/fs/vboxsf/shfl_hostintf.h > @@ -68,9 +68,9 @@ struct shfl_string { > > /** UTF-8 or UTF-16 string. Nul terminated. */ > union { > - u8 utf8[2]; > - u16 utf16[1]; > - u16 ucs2[1]; /* misnomer, use utf16. */ > + u8 legacy_padding[2]; > + DECLARE_FLEX_ARRAY(u8, utf8); > + DECLARE_FLEX_ARRAY(u16, utf16); > } string; > }; > VMMDEV_ASSERT_SIZE(shfl_string, 6);
On Thu, 20 Jul 2023 08:15:06 -0700, Kees Cook wrote: > The declaration of struct shfl_string used trailing fake flexible arrays > for the string member. This was tripping FORTIFY_SOURCE since commit > df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3"). Replace the > utf8 and utf16 members with actual flexible arrays, drop the unused ucs2 > member, and retriain a 2 byte padding to keep the structure size the same. > > > [...] Applied to for-linus/hardening, thanks! [1/1] vboxsf: Use flexible arrays for trailing string member https://git.kernel.org/kees/c/a8f014ec6a21 Best regards,
On 7/26/23 16:55, Kees Cook wrote: > > On Thu, 20 Jul 2023 08:15:06 -0700, Kees Cook wrote: >> The declaration of struct shfl_string used trailing fake flexible arrays >> for the string member. This was tripping FORTIFY_SOURCE since commit >> df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3"). Replace the >> utf8 and utf16 members with actual flexible arrays, drop the unused ucs2 >> member, and retriain a 2 byte padding to keep the structure size the same. >> >> >> [...] > > Applied to for-linus/hardening, thanks! > > [1/1] vboxsf: Use flexible arrays for trailing string member > https://git.kernel.org/kees/c/a8f014ec6a21 Kees, This patch has not been applied to kernel 6.5-rc5. Is there some problem? Larry
On Tue, Aug 08, 2023 at 02:20:06PM -0500, Larry Finger wrote: > On 7/26/23 16:55, Kees Cook wrote: > > > > On Thu, 20 Jul 2023 08:15:06 -0700, Kees Cook wrote: > > > The declaration of struct shfl_string used trailing fake flexible arrays > > > for the string member. This was tripping FORTIFY_SOURCE since commit > > > df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3"). Replace the > > > utf8 and utf16 members with actual flexible arrays, drop the unused ucs2 > > > member, and retriain a 2 byte padding to keep the structure size the same. > > > > > > > > > [...] > > > > Applied to for-linus/hardening, thanks! > > > > [1/1] vboxsf: Use flexible arrays for trailing string member > > https://git.kernel.org/kees/c/a8f014ec6a21 > > Kees, > > This patch has not been applied to kernel 6.5-rc5. Is there some problem? Hi! Sorry, I was waiting for linux-next testing, and then got distracted on Friday. I will send the PR to Linus today. Thanks for the poke! -Kees
diff --git a/fs/vboxsf/shfl_hostintf.h b/fs/vboxsf/shfl_hostintf.h index aca829062c12..069a019c9247 100644 --- a/fs/vboxsf/shfl_hostintf.h +++ b/fs/vboxsf/shfl_hostintf.h @@ -68,9 +68,9 @@ struct shfl_string { /** UTF-8 or UTF-16 string. Nul terminated. */ union { - u8 utf8[2]; - u16 utf16[1]; - u16 ucs2[1]; /* misnomer, use utf16. */ + u8 legacy_padding[2]; + DECLARE_FLEX_ARRAY(u8, utf8); + DECLARE_FLEX_ARRAY(u16, utf16); } string; }; VMMDEV_ASSERT_SIZE(shfl_string, 6);
The declaration of struct shfl_string used trailing fake flexible arrays for the string member. This was tripping FORTIFY_SOURCE since commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3"). Replace the utf8 and utf16 members with actual flexible arrays, drop the unused ucs2 member, and retriain a 2 byte padding to keep the structure size the same. Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Closes: https://lore.kernel.org/lkml/ab3a70e9-60ed-0f13-e3d4-8866eaccc8c1@lwfinger.net/ Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Kees Cook <keescook@chromium.org> --- fs/vboxsf/shfl_hostintf.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)