| Message ID | 20240617175521.1766698-1-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/ubsan: Fix UB in type_descriptor declaration | expand |
On 17.06.2024 19:55, Andrew Cooper wrote: > struct type_descriptor is arranged with a NUL terminated string following the > kind/info fields. > > The only reason this doesn't trip UBSAN detection itself (on more modern > compilers at least) is because struct type_descriptor is only referenced in > suppressed regions. > > Switch the declaration to be a real flexible member. No functional change. > > Fixes: 00fcf4dd8eb4 ("xen/ubsan: Import ubsan implementation from Linux 4.13") > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
On Mon, 2024-06-17 at 18:55 +0100, Andrew Cooper wrote: > struct type_descriptor is arranged with a NUL terminated string Should it be NULL instead of NUL? > following the > kind/info fields. > > The only reason this doesn't trip UBSAN detection itself (on more > modern > compilers at least) is because struct type_descriptor is only > referenced in > suppressed regions. > > Switch the declaration to be a real flexible member. No functional > change. > > Fixes: 00fcf4dd8eb4 ("xen/ubsan: Import ubsan implementation from > Linux 4.13") > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com> ~ Oleksii > --- > CC: George Dunlap <George.Dunlap@citrix.com> > CC: Jan Beulich <JBeulich@suse.com> > CC: Stefano Stabellini <sstabellini@kernel.org> > CC: Julien Grall <julien@xen.org> > CC: Oleksii Kurochko <oleksii.kurochko@gmail.com> > > For 4.19, and for backport to all reasonable versions. This bug > deserves some > kind of irony award. > --- > xen/common/ubsan/ubsan.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/xen/common/ubsan/ubsan.h b/xen/common/ubsan/ubsan.h > index a3159040fefb..3db42e75b138 100644 > --- a/xen/common/ubsan/ubsan.h > +++ b/xen/common/ubsan/ubsan.h > @@ -10,7 +10,7 @@ enum { > struct type_descriptor { > u16 type_kind; > u16 type_info; > - char type_name[1]; > + char type_name[]; > }; > > struct source_location { > > base-commit: 8b4243a9b560c89bb259db5a27832c253d4bebc7
On 18/06/2024 9:07 am, Oleksii K. wrote: > On Mon, 2024-06-17 at 18:55 +0100, Andrew Cooper wrote: >> struct type_descriptor is arranged with a NUL terminated string > Should it be NULL instead of NUL? NULL and NUL can be used interchangeably; they're different spellings for the same thing. In the ASCII spec, the character with value 0 is spelt NUL. > >> following the >> kind/info fields. >> >> The only reason this doesn't trip UBSAN detection itself (on more >> modern >> compilers at least) is because struct type_descriptor is only >> referenced in >> suppressed regions. >> >> Switch the declaration to be a real flexible member. No functional >> change. >> >> Fixes: 00fcf4dd8eb4 ("xen/ubsan: Import ubsan implementation from >> Linux 4.13") >> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com> Thanks. ~Andrew
diff --git a/xen/common/ubsan/ubsan.h b/xen/common/ubsan/ubsan.h index a3159040fefb..3db42e75b138 100644 --- a/xen/common/ubsan/ubsan.h +++ b/xen/common/ubsan/ubsan.h @@ -10,7 +10,7 @@ enum { struct type_descriptor { u16 type_kind; u16 type_info; - char type_name[1]; + char type_name[]; }; struct source_location {
struct type_descriptor is arranged with a NUL terminated string following the kind/info fields. The only reason this doesn't trip UBSAN detection itself (on more modern compilers at least) is because struct type_descriptor is only referenced in suppressed regions. Switch the declaration to be a real flexible member. No functional change. Fixes: 00fcf4dd8eb4 ("xen/ubsan: Import ubsan implementation from Linux 4.13") Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: George Dunlap <George.Dunlap@citrix.com> CC: Jan Beulich <JBeulich@suse.com> CC: Stefano Stabellini <sstabellini@kernel.org> CC: Julien Grall <julien@xen.org> CC: Oleksii Kurochko <oleksii.kurochko@gmail.com> For 4.19, and for backport to all reasonable versions. This bug deserves some kind of irony award. --- xen/common/ubsan/ubsan.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) base-commit: 8b4243a9b560c89bb259db5a27832c253d4bebc7