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 4.4-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-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Mar 19 09:58:12 CET 2018
From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
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@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: David S . Miller <davem@xxxxxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ye Xiaolong <xiaolong.ye@xxxxxxxxx>
Link: http://lkml.kernel.org/r/149076340615.22469.14066273186134229909.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx are
queue-4.4/perf-session-don-t-rely-on-evlist-in-pipe-mode.patch
queue-4.4/kprobes-x86-set-kprobes-pages-read-only.patch
queue-4.4/kprobes-x86-fix-kprobe-booster-not-to-boost-far-call-instructions.patch
queue-4.4/perf-inject-copy-events-when-reordering-events-in-pipe-mode.patch
queue-4.4/perf-probe-return-errno-when-not-hitting-any-event.patch