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/debuginfo.h | 66 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 tools/perf/util/debuginfo.h (limited to 'tools/perf/util/debuginfo.h') diff --git a/tools/perf/util/debuginfo.h b/tools/perf/util/debuginfo.h new file mode 100644 index 000000000..a52d69932 --- /dev/null +++ b/tools/perf/util/debuginfo.h @@ -0,0 +1,66 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _PERF_DEBUGINFO_H +#define _PERF_DEBUGINFO_H + +#include +#include + +#ifdef HAVE_LIBDW_SUPPORT + +#include "dwarf-aux.h" + +/* debug information structure */ +struct debuginfo { + Dwarf *dbg; + Dwfl_Module *mod; + Dwfl *dwfl; + Dwarf_Addr bias; + const unsigned char *build_id; +}; + +/* This also tries to open distro debuginfo */ +struct debuginfo *debuginfo__new(const char *path); +void debuginfo__delete(struct debuginfo *dbg); + +int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs, + bool adjust_offset); + +#else /* HAVE_LIBDW_SUPPORT */ + +/* dummy debug information structure */ +struct debuginfo { +}; + +static inline struct debuginfo *debuginfo__new(const char *path __maybe_unused) +{ + return NULL; +} + +static inline void debuginfo__delete(struct debuginfo *dbg __maybe_unused) +{ +} + +typedef void Dwarf_Addr; + +static inline int debuginfo__get_text_offset(struct debuginfo *dbg __maybe_unused, + Dwarf_Addr *offs __maybe_unused, + bool adjust_offset __maybe_unused) +{ + return -EINVAL; +} + +#endif /* HAVE_LIBDW_SUPPORT */ + +#ifdef HAVE_DEBUGINFOD_SUPPORT +int get_source_from_debuginfod(const char *raw_path, const char *sbuild_id, + char **new_path); +#else /* HAVE_DEBUGINFOD_SUPPORT */ +static inline int get_source_from_debuginfod(const char *raw_path __maybe_unused, + const char *sbuild_id __maybe_unused, + char **new_path __maybe_unused) +{ + return -ENOTSUP; +} +#endif /* HAVE_DEBUGINFOD_SUPPORT */ + +#endif /* _PERF_DEBUGINFO_H */ -- cgit v1.3.1