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

kprobes/x86: Blacklist indirect thunk functions for kprobes

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kprobes-x86-blacklist-indirect-thunk-functions-for-kprobes.patch and it can be found in the queue-4.9 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 c1804a236894ecc942da7dc6c5abe209e56cba93 Mon Sep 17 00:00:00 2001

From: Masami Hiramatsu mhiramat@kernel.org Date: Fri, 19 Jan 2018 01:14:51 +0900 Subject: kprobes/x86: Blacklist indirect thunk functions for kprobes

From: Masami Hiramatsu mhiramat@kernel.org

commit c1804a236894ecc942da7dc6c5abe209e56cba93 upstream.

Mark __x86_indirect_thunk_* functions as blacklist for kprobes because those functions can be called from anywhere in the kernel including blacklist functions of kprobes.

Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: David Woodhouse dwmw@amazon.co.uk Cc: Andi Kleen ak@linux.intel.com Cc: Peter Zijlstra peterz@infradead.org Cc: Ananth N Mavinakayanahalli ananth@linux.vnet.ibm.com Cc: Arjan van de Ven arjan@linux.intel.com Cc: Greg Kroah-Hartman gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/151629209111.10241.5444852823378068683.stgit@devbo... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/x86/lib/retpoline.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -25,7 +25,8 @@ ENDPROC(__x86_indirect_thunk_\reg) * than one per register with the correct names. So we do it * the simple and nasty way... */ -#define EXPORT_THUNK(reg) EXPORT_SYMBOL(__x86_indirect_thunk_ ## reg) +#define __EXPORT_THUNK(sym) _ASM_NOKPROBE(sym); EXPORT_SYMBOL(sym) +#define EXPORT_THUNK(reg) __EXPORT_THUNK(__x86_indirect_thunk_ ## reg) #define GENERATE_THUNK(reg) THUNK reg ; EXPORT_THUNK(reg)

GENERATE_THUNK(_ASM_AX)

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

queue-4.9/perf-tools-fix-build-with-arch-x86_64.patch queue-4.9/kprobes-x86-disable-optimizing-on-the-function-jumps-to-indirect-thunk.patch queue-4.9/kprobes-x86-blacklist-indirect-thunk-functions-for-kprobes.patch queue-4.9/retpoline-introduce-start-end-markers-of-indirect-thunk.patch