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/sample-raw.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 tools/perf/util/sample-raw.c (limited to 'tools/perf/util/sample-raw.c') diff --git a/tools/perf/util/sample-raw.c b/tools/perf/util/sample-raw.c new file mode 100644 index 000000000..e20b73c0c --- /dev/null +++ b/tools/perf/util/sample-raw.c @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include "sample-raw.h" + +#include +#include + +#include "env.h" +#include "evlist.h" +#include "header.h" +#include "session.h" + +/* + * Check platform the perf data file was created on and perform platform + * specific interpretation. + */ +void evlist__init_trace_event_sample_raw(struct evlist *evlist, struct perf_env *env) +{ + uint16_t e_machine = perf_env__e_machine(env, /*e_flags=*/NULL); + + if (e_machine == EM_S390) { + evlist->trace_event_sample_raw = evlist__s390_sample_raw; + } else if (e_machine == EM_X86_64 || e_machine == EM_386) { + const char *cpuid = perf_env__cpuid(env); + + if (cpuid && strstarts(cpuid, "AuthenticAMD") && evlist__has_amd_ibs(evlist)) + evlist->trace_event_sample_raw = evlist__amd_sample_raw; + } +} -- cgit v1.3.1