Patch "MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accesses" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accesses

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:
     mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.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@vger.kernel.org> know about it.


>From c8c5a3a24d395b14447a9a89d61586a913840a3b Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@mips.com>
Date: Mon, 11 Dec 2017 22:56:54 +0000
Subject: MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accesses

From: Maciej W. Rozycki <macro@mips.com>

commit c8c5a3a24d395b14447a9a89d61586a913840a3b upstream.

Complement commit c23b3d1a5311 ("MIPS: ptrace: Change GP regset to use
correct core dump register layout") and also reject outsized
PTRACE_SETREGSET requests to the NT_PRFPREG regset, like with the
NT_PRSTATUS regset.

Signed-off-by: Maciej W. Rozycki <macro@mips.com>
Fixes: c23b3d1a5311 ("MIPS: ptrace: Change GP regset to use correct core dump register layout")
Cc: James Hogan <james.hogan@mips.com>
Cc: Paul Burton <Paul.Burton@mips.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17930/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/ptrace.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -570,6 +570,9 @@ static int fpr_set(struct task_struct *t
 
 	BUG_ON(count % sizeof(elf_fpreg_t));
 
+	if (pos + count > sizeof(elf_fpregset_t))
+		return -EIO;
+
 	init_fp_ctx(target);
 
 	if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))


Patches currently in stable-queue which might be from macro@mips.com are

queue-4.4/mips-consistently-handle-buffer-counter-with-ptrace_setregset.patch
queue-4.4/mips-disallow-outsized-ptrace_setregset-nt_prfpreg-regset-accesses.patch
queue-4.4/mips-guard-against-any-partial-write-attempt-with-ptrace_setregset.patch
queue-4.4/mips-also-verify-sizeof-elf_fpreg_t-with-ptrace_setregset.patch
queue-4.4/mips-factor-out-nt_prfpreg-regset-access-helpers.patch
queue-4.4/mips-validate-pr_set_fp_mode-prctl-2-requests-against-the-abi-of-the-task.patch
queue-4.4/mips-fix-an-fcsr-access-api-regression-with-nt_prfpreg-and-msa.patch