From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Tue, 9 Jan 2018 04:09:53 +0000 (-0500)
Subject: x86/ia32: don't save registers on audit call
X-Git-Tag: v4.1.12-124.31.3~1282
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8c51a99e0cbbb8fab93159d39eb6c437caa6f2d0;p=users%2Fjedix%2Flinux-maple.git

x86/ia32: don't save registers on audit call

This is a followup on (x86/ia32: save and clear registers on syscall.)
where we would save the registers at the start of the system call
and also clear them (r8->15). But the ptrace syscall would do
the same thing (save) which meant we would end up over-writting them
with zeros.

Orabug: 27344012
CVE:CVE-2017-5715

Reviewed-by: Kris Van Hees <kris.van.hees@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Kirtikar Kashyap <kirtikar.kashyap@oracle.com>
---

diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 36d3ec7e4cdc..7b268913340f 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -313,7 +313,6 @@ sysenter_tracesys:
 	testl	$(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
 	jz	sysenter_auditsys
 #endif
-	SAVE_EXTRA_REGS
 	CLEAR_RREGS
 	movq	$-ENOSYS,RAX(%rsp)/* ptrace can change this for a bad syscall */
 	movq	%rsp,%rdi        /* &pt_regs -> arg1 */