[PATCH 5/8] perf header: Use a max number of command line args

Arnaldo Carvalho de Melo
2026-04-08T17:32:39Z

Sashiko suggests we use some reasonable max number of args to avoid
overflows when reading perf.data files, do it.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/header.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index a3b7b796639b42c0..a18f216f77c27430 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2795,6 +2795,9 @@ process_event_desc(struct feat_fd *ff, void *data __maybe_unused)
return 0;
}

+// Some reasonable arbitrary max for the number of command line arguments
+#define MAX_CMDLINE_NR 32768
+
static int process_cmdline(struct feat_fd *ff, void *data __maybe_unused)
{
struct perf_env *env = &ff->ph->env;
@@ -2804,6 +2807,9 @@ static int process_cmdline(struct feat_fd *ff, void *data __maybe_unused)
if (do_read_u32(ff, &nr))
return -1;

+ if (nr > MAX_CMDLINE_NR)
+ return -1;
+
env->nr_cmdline = nr;

cmdline = zalloc(ff->size + nr + 1);
--
2.53.0