On Sun, Aug 25, 2019 at 04:18:56PM -0700, Kees Cook wrote: > As we've done with VFS, string operations, etc, reject usercopy sizes > larger than INT_MAX, which would be nice to have for catching bugs > related to size calculation overflows[1]. > > This adds 10 bytes to x86_64 defconfig text and 1980 bytes to the data > section: > > text data bss dec hex filename > 19691167 5134320 1646664 26472151 193eed7 vmlinux.before > 19691177 5136300 1646664 26474141 193f69d vmlinux.after > > [1] https://marc.info/?l=linux-s390&m=156631939010493&w=2 > > Suggested-by: Dan Carpenter <dan.carpen...@oracle.com> > Signed-off-by: Kees Cook <keesc...@chromium.org>
ping! Andrew, can you take this? -Kees > --- > include/linux/thread_info.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h > index 659a4400517b..e93e249a4e9b 100644 > --- a/include/linux/thread_info.h > +++ b/include/linux/thread_info.h > @@ -147,6 +147,8 @@ check_copy_size(const void *addr, size_t bytes, bool > is_source) > __bad_copy_to(); > return false; > } > + if (WARN_ON_ONCE(bytes > INT_MAX)) > + return false; > check_object_size(addr, bytes, is_source); > return true; > } > -- > 2.17.1 > > > -- > Kees Cook -- Kees Cook
