Patch "kprobes/x86: Fix kprobe-booster not to boost far call instructions" has been added to the 3.18-stable tree

Patch "kprobes/x86: Fix kprobe-booster not to boost far call instructions" has been added to the 3.18-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    kprobes/x86: Fix kprobe-booster not to boost far call instructions

to the 3.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kprobes-x86-fix-kprobe-booster-not-to-boost-far-call-instructions.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Mar 19 10:11:52 CET 2018
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Wed, 29 Mar 2017 13:56:56 +0900
Subject: kprobes/x86: Fix kprobe-booster not to boost far call instructions

From: Masami Hiramatsu <mhiramat@kernel.org>


[ Upstream commit bd0b90676c30fe640e7ead919b3e38846ac88ab7 ]

Fix the kprobe-booster not to boost far call instruction,
because a call may store the address in the single-step
execution buffer to the stack, which should be modified
after single stepping.

Currently, this instruction will be filtered as not
boostable in resume_execution(), so this is not a
critical issue.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ye Xiaolong <xiaolong.ye@intel.com>
Link: http://lkml.kernel.org/r/149076340615.22469.14066273186134229909.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/kernel/kprobes/core.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -196,6 +196,8 @@ retry:
 		return (opcode != 0x62 && opcode != 0x67);
 	case 0x70:
 		return 0; /* can't boost conditional jump */
+	case 0x90:
+		return opcode != 0x9a;	/* can't boost call far */
 	case 0xc0:
 		/* can't boost software-interruptions */
 		return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf;


Patches currently in stable-queue which might be from mhiramat@kernel.org are

queue-3.18/perf-session-don-t-rely-on-evlist-in-pipe-mode.patch
queue-3.18/kprobes-x86-set-kprobes-pages-read-only.patch
queue-3.18/kprobes-x86-fix-kprobe-booster-not-to-boost-far-call-instructions.patch
queue-3.18/perf-inject-copy-events-when-reordering-events-in-pipe-mode.patch