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 --- scripts/modules-check.sh | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100755 scripts/modules-check.sh (limited to 'scripts/modules-check.sh') diff --git a/scripts/modules-check.sh b/scripts/modules-check.sh new file mode 100755 index 000000000..4c8da90de --- /dev/null +++ b/scripts/modules-check.sh @@ -0,0 +1,26 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +set -e + +if [ $# != 1 ]; then + echo "Usage: $0 " >& 2 + exit 1 +fi + +exit_code=0 + +# Check uniqueness of module names +check_same_name_modules() +{ + for m in $(sed 's:.*/::' "$1" | sort | uniq -d) + do + echo "error: the following would cause module name conflict:" >&2 + sed -n "/\/$m/s:^\(.*\)\.o\$: \1.ko:p" "$1" >&2 + exit_code=1 + done +} + +check_same_name_modules "$1" + +exit $exit_code -- cgit v1.3.1