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/checkdeclares.pl | 53 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100755 scripts/checkdeclares.pl (limited to 'scripts/checkdeclares.pl') diff --git a/scripts/checkdeclares.pl b/scripts/checkdeclares.pl new file mode 100755 index 000000000..f6d551c84 --- /dev/null +++ b/scripts/checkdeclares.pl @@ -0,0 +1,53 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 +# +# checkdeclares: find struct declared more than once +# +# Copyright 2021 Wan Jiabing +# Inspired by checkincludes.pl +# +# This script checks for duplicate struct declares. +# Note that this will not take into consideration macros so +# you should run this only if you know you do have real dups +# and do not have them under #ifdef's. +# You could also just review the results. + +use strict; + +sub usage { + print "Usage: checkdeclares.pl file1.h ...\n"; + print "Warns of struct declaration duplicates\n"; + exit 1; +} + +if ($#ARGV < 0) { + usage(); +} + +my $dup_counter = 0; + +foreach my $file (@ARGV) { + open(my $f, '<', $file) + or die "Cannot open $file: $!.\n"; + + my %declaredstructs = (); + + while (<$f>) { + if (m/^\s*struct\s*(\w*);$/o) { + ++$declaredstructs{$1}; + } + } + + close($f); + + foreach my $structname (keys %declaredstructs) { + if ($declaredstructs{$structname} > 1) { + print "$file: struct $structname is declared more than once.\n"; + ++$dup_counter; + } + } +} + +if ($dup_counter == 0) { + print "No duplicate struct declares found.\n"; +} -- cgit v1.3.1