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/demangle-cxx.cpp | 49 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 tools/perf/util/demangle-cxx.cpp (limited to 'tools/perf/util/demangle-cxx.cpp') diff --git a/tools/perf/util/demangle-cxx.cpp b/tools/perf/util/demangle-cxx.cpp new file mode 100644 index 000000000..85b706641 --- /dev/null +++ b/tools/perf/util/demangle-cxx.cpp @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "demangle-cxx.h" +#include +#include +#include + +#ifdef HAVE_LIBBFD_SUPPORT +#define PACKAGE 'perf' +#include +#endif + +#ifdef HAVE_CXA_DEMANGLE_SUPPORT +#include +#endif + +#if defined(HAVE_LIBBFD_SUPPORT) || defined(HAVE_CPLUS_DEMANGLE_SUPPORT) +#ifndef DMGL_PARAMS +#define DMGL_PARAMS (1 << 0) /* Include function args */ +#define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */ +#endif +#endif + +/* + * Demangle C++ function signature + * + * Note: caller is responsible for freeing demangled string + */ +extern "C" +char *cxx_demangle_sym(const char *str, bool params __maybe_unused, + bool modifiers __maybe_unused) +{ +#ifdef HAVE_LIBBFD_SUPPORT + int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0); + + return bfd_demangle(NULL, str, flags); +#elif defined(HAVE_CPLUS_DEMANGLE_SUPPORT) + int flags = (params ? DMGL_PARAMS : 0) | (modifiers ? DMGL_ANSI : 0); + + return cplus_demangle(str, flags); +#elif defined(HAVE_CXA_DEMANGLE_SUPPORT) + char *output; + int status; + + output = abi::__cxa_demangle(str, /*output_buffer=*/NULL, /*length=*/NULL, &status); + return output; +#else + return NULL; +#endif +} -- cgit v1.3.1