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/counts.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 tools/perf/util/counts.c (limited to 'tools/perf/util/counts.c') diff --git a/tools/perf/util/counts.c b/tools/perf/util/counts.c new file mode 100644 index 000000000..11cd85b27 --- /dev/null +++ b/tools/perf/util/counts.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include "evsel.h" +#include "counts.h" +#include +#include + +struct perf_counts *perf_counts__new(int ncpus, int nthreads) +{ + struct perf_counts *counts = zalloc(sizeof(*counts)); + + if (counts) { + struct xyarray *values; + + values = xyarray__new(ncpus, nthreads, sizeof(struct perf_counts_values)); + if (!values) { + free(counts); + return NULL; + } + + counts->values = values; + + values = xyarray__new(ncpus, nthreads, sizeof(bool)); + if (!values) { + xyarray__delete(counts->values); + free(counts); + return NULL; + } + + counts->loaded = values; + } + + return counts; +} + +void perf_counts__delete(struct perf_counts *counts) +{ + if (counts) { + xyarray__delete(counts->loaded); + xyarray__delete(counts->values); + free(counts); + } +} + +void perf_counts__reset(struct perf_counts *counts) +{ + xyarray__reset(counts->loaded); + xyarray__reset(counts->values); +} + +void evsel__reset_counts(struct evsel *evsel) +{ + perf_counts__reset(evsel->counts); +} + +int evsel__alloc_counts(struct evsel *evsel) +{ + struct perf_cpu_map *cpus = evsel__cpus(evsel); + int nthreads = perf_thread_map__nr(evsel->core.threads); + + evsel->counts = perf_counts__new(perf_cpu_map__nr(cpus), nthreads); + return evsel->counts != NULL ? 0 : -ENOMEM; +} + +void evsel__free_counts(struct evsel *evsel) +{ + perf_counts__delete(evsel->counts); + evsel->counts = NULL; +} -- cgit v1.3.1