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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2026-07-27 13:17:05 -0300 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2026-08-03 12:43:10 -0700 |
| commit | d67241d43b709af4d13051bb8494892b654aba41 (patch) | |
| tree | 7bd4c89c7630c98cb5171ad39f3b98cf2ab69f2e | |
| parent | b9fb8225951ce27e62a2235a71f3ab01137aaec3 (diff) | |
| download | linux-d67241d43b709af4d13051bb8494892b654aba41.tar.gz linux-d67241d43b709af4d13051bb8494892b654aba41.zip | |
perf arm-spe: Reject zero nr_cpu in metadata to prevent division by zero
arm_spe__alloc_metadata() reads nr_cpu from the auxtrace_info priv
array without validation. When a crafted perf.data provides nr_cpu=0,
the per_cpu_sz calculation divides by zero:
per_cpu_sz = (metadata_size - (hdr_sz * sizeof(u64))) / (*nr_cpu);
Reject nr_cpu <= 0 early, before the division. The caller already
treats NULL return with metadata_ver != 1 as a parse failure.
Fixes: 7842a4b6ff698 ("perf arm-spe: Support metadata version 2")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
| -rw-r--r-- | tools/perf/util/arm-spe.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c index 552f063f126e..401aab529309 100644 --- a/tools/perf/util/arm-spe.c +++ b/tools/perf/util/arm-spe.c @@ -1605,6 +1605,10 @@ static u64 **arm_spe__alloc_metadata(struct perf_record_auxtrace_info *info, hdr_sz = ptr[ARM_SPE_HEADER_SIZE]; *nr_cpu = ptr[ARM_SPE_CPUS_NUM]; + /* nr_cpu is used as a divisor below */ + if (*nr_cpu <= 0) + return NULL; + metadata = calloc(*nr_cpu, sizeof(*metadata)); if (!metadata) return NULL; |