Patch "ARM: 8643/3: arm/ptrace: Preserve previous registers for short regset write" has been added to the 4.9-stable tree

Patch "ARM: 8643/3: arm/ptrace: Preserve previous registers for short regset write" has been added to the 4.9-stable tree

[gregkh]

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

    ARM: 8643/3: arm/ptrace: Preserve previous registers for short regset write

to the 4.9-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:
     arm-8643-3-arm-ptrace-preserve-previous-registers-for-short-regset-write.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 228dbbfb5d77f8e047b2a1d78da14b7158433027 Mon Sep 17 00:00:00 2001
From: Dave Martin <Dave.Martin@arm.com>
Date: Wed, 18 Jan 2017 17:11:56 +0100
Subject: ARM: 8643/3: arm/ptrace: Preserve previous registers for short regset write

From: Dave Martin <Dave.Martin@arm.com>

commit 228dbbfb5d77f8e047b2a1d78da14b7158433027 upstream.

Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.

Fixes: 5be6f62b0059 ("ARM: 6883/1: ptrace: Migrate to regsets framework")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm/kernel/ptrace.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -600,7 +600,7 @@ static int gpr_set(struct task_struct *t
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	struct pt_regs newregs;
+	struct pt_regs newregs = *task_pt_regs(target);
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 				 &newregs,


Patches currently in stable-queue which might be from Dave.Martin@arm.com are

queue-4.9/arm-8643-3-arm-ptrace-preserve-previous-registers-for-short-regset-write.patch