Messages in this thread |  | | Date | Wed, 6 Sep 2017 17:44:22 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v8 07/28] x86/mpx: Do not use SIB.base if its value is 101b and ModRM.mod = 0 |
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On Fri, Aug 18, 2017 at 05:27:48PM -0700, Ricardo Neri wrote: > Section 2.2.1.2 of the Intel 64 and IA-32 Architectures Software > Developer's Manual volume 2A states that if a SIB byte is used and > SIB.base is 101b and ModRM.mod is zero, then the base part of the base > part of the effective address computation is null. To signal this > situation, a -EDOM error is returned to indicate callers to ignore the > base value present in the register operand. > > In this scenario, a 32-bit displacement follows the SIB byte. Displacement > is obtained when the instruction decoder parses the operands. > > Cc: Borislav Petkov <bp@suse.de> > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: Adam Buchbinder <adam.buchbinder@gmail.com> > Cc: Colin Ian King <colin.king@canonical.com> > Cc: Lorenzo Stoakes <lstoakes@gmail.com> > Cc: Qiaowei Ren <qiaowei.ren@intel.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Nathan Howard <liverlint@gmail.com> > Cc: Adan Hawthorn <adanhawthorn@gmail.com> > Cc: Joe Perches <joe@perches.com> > Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> > Cc: x86@kernel.org > Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> > --- > arch/x86/mm/mpx.c | 28 +++++++++++++++++++--------- > 1 file changed, 19 insertions(+), 9 deletions(-)
Reviewed-by: Borislav Petkov <bp@suse.de>
-- Regards/Gruss, Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
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