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/aslr.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 tools/perf/util/aslr.h (limited to 'tools/perf/util/aslr.h') diff --git a/tools/perf/util/aslr.h b/tools/perf/util/aslr.h new file mode 100644 index 000000000..522e31c8e --- /dev/null +++ b/tools/perf/util/aslr.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_ASLR_H +#define __PERF_ASLR_H + +#include + +#define ASLR_SUPPORTED_SAMPLE_TYPE ( \ + PERF_SAMPLE_IDENTIFIER | \ + PERF_SAMPLE_IP | \ + PERF_SAMPLE_TID | \ + PERF_SAMPLE_TIME | \ + PERF_SAMPLE_ADDR | \ + PERF_SAMPLE_ID | \ + PERF_SAMPLE_STREAM_ID | \ + PERF_SAMPLE_CPU | \ + PERF_SAMPLE_PERIOD | \ + PERF_SAMPLE_READ | \ + PERF_SAMPLE_CALLCHAIN | \ + PERF_SAMPLE_RAW | \ + PERF_SAMPLE_BRANCH_STACK | \ + PERF_SAMPLE_STACK_USER | \ + PERF_SAMPLE_WEIGHT_TYPE | \ + PERF_SAMPLE_DATA_SRC | \ + PERF_SAMPLE_TRANSACTION | \ + PERF_SAMPLE_PHYS_ADDR | \ + PERF_SAMPLE_CGROUP | \ + PERF_SAMPLE_DATA_PAGE_SIZE | \ + PERF_SAMPLE_CODE_PAGE_SIZE | \ + PERF_SAMPLE_AUX) + +struct perf_tool; +struct evsel; +struct evlist; +union perf_event; + +struct perf_tool *aslr_tool__new(struct perf_tool *delegate); +void aslr_tool__delete(struct perf_tool *tool); + +void aslr_tool__strip_attr_event(union perf_event *event, struct evlist *evlist); +int aslr_tool__cache_orig_attrs(struct perf_tool *tool, struct evsel *evsel); +void aslr_tool__strip_evlist(const struct perf_tool *tool, struct evlist *evlist); +void aslr_tool__restore_evlist(const struct perf_tool *tool, struct evlist *evlist); + +#endif /* __PERF_ASLR_H */ -- cgit v1.3.1