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/tests/mem2node.c | 82 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 tools/perf/tests/mem2node.c (limited to 'tools/perf/tests/mem2node.c') diff --git a/tools/perf/tests/mem2node.c b/tools/perf/tests/mem2node.c new file mode 100644 index 000000000..7ce1ad7b6 --- /dev/null +++ b/tools/perf/tests/mem2node.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include "debug.h" +#include "env.h" +#include "mem2node.h" +#include "tests.h" + +static struct node { + int node; + const char *map; +} test_nodes[] = { + { .node = 0, .map = "0" }, + { .node = 1, .map = "1-2" }, + { .node = 3, .map = "5-7,9" }, +}; + +#define T TEST_ASSERT_VAL + +static unsigned long *get_bitmap(const char *str, int nbits) +{ + struct perf_cpu_map *map = perf_cpu_map__new(str); + unsigned long *bm = NULL; + + bm = bitmap_zalloc(nbits); + + if (map && bm) { + struct perf_cpu cpu; + unsigned int i; + + perf_cpu_map__for_each_cpu(cpu, i, map) + __set_bit(cpu.cpu, bm); + } + + if (map) + perf_cpu_map__put(map); + else + free(bm); + + return bm && map ? bm : NULL; +} + +static int test__mem2node(struct test_suite *t __maybe_unused, int subtest __maybe_unused) +{ + struct mem2node map; + struct memory_node nodes[3]; + struct perf_env env = { + .memory_nodes = (struct memory_node *) &nodes[0], + .nr_memory_nodes = ARRAY_SIZE(nodes), + .memory_bsize = 0x100, + }; + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(nodes); i++) { + nodes[i].node = test_nodes[i].node; + nodes[i].size = 10; + + T("failed: alloc bitmap", + (nodes[i].set = get_bitmap(test_nodes[i].map, 10))); + } + + T("failed: mem2node__init", !mem2node__init(&map, &env)); + T("failed: mem2node__node", 0 == mem2node__node(&map, 0x50)); + T("failed: mem2node__node", 1 == mem2node__node(&map, 0x100)); + T("failed: mem2node__node", 1 == mem2node__node(&map, 0x250)); + T("failed: mem2node__node", 3 == mem2node__node(&map, 0x500)); + T("failed: mem2node__node", 3 == mem2node__node(&map, 0x650)); + T("failed: mem2node__node", -1 == mem2node__node(&map, 0x450)); + T("failed: mem2node__node", -1 == mem2node__node(&map, 0x1050)); + + for (i = 0; i < ARRAY_SIZE(nodes); i++) + zfree(&nodes[i].set); + + mem2node__exit(&map); + return 0; +} + +DEFINE_SUITE("mem2node", mem2node); -- cgit v1.3.1