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-hooks.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 tools/perf/util/perf-hooks.h (limited to 'tools/perf/util/perf-hooks.h') diff --git a/tools/perf/util/perf-hooks.h b/tools/perf/util/perf-hooks.h new file mode 100644 index 000000000..27fbec62d --- /dev/null +++ b/tools/perf/util/perf-hooks.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef PERF_UTIL_PERF_HOOKS_H +#define PERF_UTIL_PERF_HOOKS_H + +#ifdef __cplusplus +extern "C" { +#endif + +typedef void (*perf_hook_func_t)(void *ctx); +struct perf_hook_desc { + const char * const hook_name; + perf_hook_func_t * const p_hook_func; + void *hook_ctx; +}; + +extern void perf_hooks__invoke(const struct perf_hook_desc *); +extern void perf_hooks__recover(void); + +#define PERF_HOOK(name) \ +extern struct perf_hook_desc __perf_hook_desc_##name; \ +static inline void perf_hooks__invoke_##name(void) \ +{ \ + perf_hooks__invoke(&__perf_hook_desc_##name); \ +} + +#include "perf-hooks-list.h" +#undef PERF_HOOK + +extern int +perf_hooks__set_hook(const char *hook_name, + perf_hook_func_t hook_func, + void *hook_ctx); + +extern perf_hook_func_t +perf_hooks__get_hook(const char *hook_name); + +#ifdef __cplusplus +} +#endif +#endif -- cgit v1.3.1