Messages in this thread | | | Subject | Re: [PATCH v4 07/10] x86: narrow out of bounds syscalls to sys_read under speculation | From | Jiri Slaby <> | Date | Wed, 24 Jan 2018 15:40:40 +0100 |
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On 01/19/2018, 01:02 AM, Dan Williams wrote: > The syscall table base is a user controlled function pointer in kernel > space. Like, 'get_user, use 'MASK_NOSPEC' to prevent any out of bounds > speculation. While retpoline prevents speculating into the user > controlled target it does not stop the pointer de-reference, the concern > is leaking memory relative to the syscall table base. > > Reported-by: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: x86@kernel.org > Cc: Andy Lutomirski <luto@kernel.org> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > arch/x86/entry/entry_64.S | 2 ++ > arch/x86/include/asm/smap.h | 9 ++++++++- > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S > index 4f8e1d35a97c..2320017077d4 100644 > --- a/arch/x86/entry/entry_64.S > +++ b/arch/x86/entry/entry_64.S > @@ -35,6 +35,7 @@ > #include <asm/asm.h> > #include <asm/smap.h> > #include <asm/pgtable_types.h> > +#include <asm/smap.h>
This is already included 2 lines above
thanks, -- js suse labs
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