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 --- tools/perf/util/PERF-VERSION-GEN | 52 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100755 tools/perf/util/PERF-VERSION-GEN (limited to 'tools/perf/util/PERF-VERSION-GEN') diff --git a/tools/perf/util/PERF-VERSION-GEN b/tools/perf/util/PERF-VERSION-GEN new file mode 100755 index 000000000..d7dc7c285 --- /dev/null +++ b/tools/perf/util/PERF-VERSION-GEN @@ -0,0 +1,52 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +if [ $# -eq 1 ] ; then + OUTPUT=$1 +fi + +GVF=${OUTPUT}PERF-VERSION-FILE + +LF=' +' + +# +# Use version from kernel Makefile unless not in a git repository and +# PERF-VERSION-FILE exists +# +CID= +TAG= +if test -d ../../.git -o -f ../../.git +then + TAG=$(MAKEFLAGS= make -sC ../.. kernelversion) + CID=$(git log -1 --abbrev=12 --pretty=format:"%h" --no-show-signature 2>/dev/null) && CID="-g$CID" +elif test -f ../../PERF-VERSION-FILE +then + TAG=$(cut -d' ' -f3 ../../PERF-VERSION-FILE | sed -e 's/\"//g') +fi +if test -z "$TAG" +then + TAG=$(MAKEFLAGS= make -sC ../.. kernelversion) +fi + +VN="$TAG$CID" +if test -n "$CID" +then + # format version string, strip trailing zero of sublevel: + VN=$(echo "$VN" | sed -e 's/-/./g;s/\([0-9]*[.][0-9]*\)[.]0/\1/') +fi + +VN=$(expr "$VN" : v*'\(.*\)') + +if test -r $GVF +then + VC=$(sed -e 's/^#define PERF_VERSION "\(.*\)"/\1/' <$GVF) +else + VC=unset +fi +test "$VN" = "$VC" || { + echo >&2 " PERF_VERSION = $VN" + echo "#define PERF_VERSION \"$VN\"" >$GVF +} + + -- cgit v1.3.1