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/tracepoint.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 tools/perf/util/tracepoint.h (limited to 'tools/perf/util/tracepoint.h') diff --git a/tools/perf/util/tracepoint.h b/tools/perf/util/tracepoint.h new file mode 100644 index 000000000..65ccb01fc --- /dev/null +++ b/tools/perf/util/tracepoint.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_TRACEPOINT_H +#define __PERF_TRACEPOINT_H + +#include +#include +#include + +int tp_event_has_id(const char *dir_path, struct dirent *evt_dir); + +#define for_each_event(dir_path, evt_dir, evt_dirent) \ + while ((evt_dirent = readdir(evt_dir)) != NULL) \ + if (evt_dirent->d_type == DT_DIR && \ + (strcmp(evt_dirent->d_name, ".")) && \ + (strcmp(evt_dirent->d_name, "..")) && \ + (!tp_event_has_id(dir_path, evt_dirent))) + +#define for_each_subsystem(sys_dir, sys_dirent) \ + while ((sys_dirent = readdir(sys_dir)) != NULL) \ + if (sys_dirent->d_type == DT_DIR && \ + (strcmp(sys_dirent->d_name, ".")) && \ + (strcmp(sys_dirent->d_name, ".."))) + +bool is_valid_tracepoint(const char *event_string); + +#endif /* __PERF_TRACEPOINT_H */ -- cgit v1.3.1