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/bitmap.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 tools/perf/tests/bitmap.c (limited to 'tools/perf/tests/bitmap.c') diff --git a/tools/perf/tests/bitmap.c b/tools/perf/tests/bitmap.c new file mode 100644 index 000000000..e7adf60be --- /dev/null +++ b/tools/perf/tests/bitmap.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include "tests.h" +#include "debug.h" + +#define NBITS 100 + +static unsigned long *get_bitmap(const char *str, int nbits) +{ + struct perf_cpu_map *map = perf_cpu_map__new(str); + unsigned long *bm; + + bm = bitmap_zalloc(nbits); + + if (map && bm) { + unsigned int i; + struct perf_cpu cpu; + + perf_cpu_map__for_each_cpu(cpu, i, map) + __set_bit(cpu.cpu, bm); + } + + perf_cpu_map__put(map); + return bm; +} + +static int test_bitmap(const char *str) +{ + unsigned long *bm = get_bitmap(str, NBITS); + char buf[100]; + int ret; + + bitmap_scnprintf(bm, NBITS, buf, sizeof(buf)); + pr_debug("bitmap: %s\n", buf); + + ret = !strcmp(buf, str); + free(bm); + return ret; +} + +static int test__bitmap_print(struct test_suite *test __maybe_unused, int subtest __maybe_unused) +{ + TEST_ASSERT_VAL("failed to convert map", test_bitmap("1")); + TEST_ASSERT_VAL("failed to convert map", test_bitmap("1,5")); + TEST_ASSERT_VAL("failed to convert map", test_bitmap("1,3,5,7,9,11,13,15,17,19,21-40")); + TEST_ASSERT_VAL("failed to convert map", test_bitmap("2-5")); + TEST_ASSERT_VAL("failed to convert map", test_bitmap("1,3-6,8-10,24,35-37")); + TEST_ASSERT_VAL("failed to convert map", test_bitmap("1,3-6,8-10,24,35-37")); + TEST_ASSERT_VAL("failed to convert map", test_bitmap("1-10,12-20,22-30,32-40")); + return 0; +} + +DEFINE_SUITE("Print bitmap", bitmap_print); -- cgit v1.3.1