| Message ID | 6fc55df2-5d92-4f3f-8eb3-69bd89bfea4e@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [for-4.19] xen: re-add type checking to {,__}copy_from_guest_offset() | expand |
On 24/06/2024 1:26 pm, Jan Beulich wrote: > When re-working them to avoid UB on guest address calculations, I failed > to add explicit type checks in exchange for the implicit ones that until > then had happened in assignments that were there anyway. > > Fixes: 43d5c5d5f70b ("xen: avoid UB in guest handle arithmetic") > Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
On Mon, 2024-06-24 at 14:20 +0100, Andrew Cooper wrote: > On 24/06/2024 1:26 pm, Jan Beulich wrote: > > When re-working them to avoid UB on guest address calculations, I > > failed > > to add explicit type checks in exchange for the implicit ones that > > until > > then had happened in assignments that were there anyway. > > > > Fixes: 43d5c5d5f70b ("xen: avoid UB in guest handle arithmetic") > > Signed-off-by: Jan Beulich <jbeulich@suse.com> > > Acked-by: Andrew Cooper <andrew.cooper3@citrix.com> Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com> ~ Oleksii
--- a/xen/include/xen/guest_access.h +++ b/xen/include/xen/guest_access.h @@ -86,6 +86,7 @@ #define copy_from_guest_offset(ptr, hnd, off, nr) ({ \ unsigned long s_ = (unsigned long)(hnd).p; \ typeof(*(ptr)) *_d = (ptr); \ + (void)((hnd).p == _d); \ raw_copy_from_guest(_d, \ (const void *)(s_ + (off) * sizeof(*_d)), \ (nr) * sizeof(*_d)); \ @@ -140,6 +141,7 @@ #define __copy_from_guest_offset(ptr, hnd, off, nr) ({ \ unsigned long s_ = (unsigned long)(hnd).p; \ typeof(*(ptr)) *_d = (ptr); \ + (void)((hnd).p == _d); \ __raw_copy_from_guest(_d, \ (const void *)(s_ + (off) * sizeof(*_d)), \ (nr) * sizeof(*_d)); \
When re-working them to avoid UB on guest address calculations, I failed to add explicit type checks in exchange for the implicit ones that until then had happened in assignments that were there anyway. Fixes: 43d5c5d5f70b ("xen: avoid UB in guest handle arithmetic") Signed-off-by: Jan Beulich <jbeulich@suse.com>