From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- arch/arm/boot/install.sh | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100755 arch/arm/boot/install.sh (limited to 'arch/arm/boot/install.sh') diff --git a/arch/arm/boot/install.sh b/arch/arm/boot/install.sh new file mode 100755 index 000000000..34e2c6e31 --- /dev/null +++ b/arch/arm/boot/install.sh @@ -0,0 +1,47 @@ +#!/bin/sh +# +# This file is subject to the terms and conditions of the GNU General Public +# License. See the file "COPYING" in the main directory of this archive +# for more details. +# +# Copyright (C) 1995 by Linus Torvalds +# +# Adapted from code in arch/i386/boot/Makefile by H. Peter Anvin +# Adapted from code in arch/i386/boot/install.sh by Russell King +# +# "make install" script for arm architecture +# +# Arguments: +# $1 - kernel version +# $2 - kernel image file +# $3 - kernel map file +# $4 - default install path (blank if root directory) + +set -e + +if [ "$(basename $2)" = "zImage" ]; then +# Compressed install + echo "Installing compressed kernel" + base=vmlinuz +else +# Normal install + echo "Installing normal kernel" + base=vmlinux +fi + +if [ -f $4/$base-$1 ]; then + mv $4/$base-$1 $4/$base-$1.old +fi +cat $2 > $4/$base-$1 + +# Install system map file +if [ -f $4/System.map-$1 ]; then + mv $4/System.map-$1 $4/System.map-$1.old +fi +cp $3 $4/System.map-$1 + +if [ -x /sbin/loadmap ]; then + /sbin/loadmap +else + echo "You have to install it yourself" +fi -- cgit v1.3.1