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/stackusage | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100755 scripts/stackusage (limited to 'scripts/stackusage') diff --git a/scripts/stackusage b/scripts/stackusage new file mode 100755 index 000000000..56ef1ab67 --- /dev/null +++ b/scripts/stackusage @@ -0,0 +1,34 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +outfile="" +now=`date +%s` + +while [ $# -gt 0 ] +do + case "$1" in + -o) + outfile="$2" + shift 2;; + -h) + echo "usage: $0 [-o outfile] " + exit 0;; + *) break;; + esac +done + +if [ -z "$outfile" ] +then + outfile=`mktemp --tmpdir stackusage.$$.XXXX` +fi + +KCFLAGS="${KCFLAGS} -fstack-usage" make "$@" + +# Prepend directory name to file names, remove column information, +# make file:line/function/size/type properly tab-separated. +find . -name '*.su' -newermt "@${now}" -print | \ + xargs perl -MFile::Basename -pe \ + '$d = dirname($ARGV); s#([^:]+:[0-9]+):[0-9]+:#$d/$1\t#;' | \ + sort -k3,3nr > "${outfile}" + +echo "$0: output written to ${outfile}" -- cgit v1.3.1