perf header: Sanity check HEADER_CACHE

Add upper bound check on cache entry count in process_cache() to harden
against malformed perf.data files (max 32768).

Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Assisted-by: Claude Code:claude-opus-4-6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 993e20debd5ca31545e1ca4c2c305097cfadf2cb..749a522fe057e73999d44b5931251a5d293d8bea 100644 (file)
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -63,6 +63,7 @@
 #include <event-parse.h>
 #endif
 
+#define MAX_CACHE_ENTRIES      32768
 #define MAX_GROUP_DESC         32768
 #define MAX_NUMA_NODES         4096
 #define MAX_PMU_MAPPINGS       4096
@@ -3243,6 +3244,18 @@ static int process_cache(struct feat_fd *ff, void *data __maybe_unused)
        if (do_read_u32(ff, &cnt))
                return -1;
 
+       if (cnt > MAX_CACHE_ENTRIES) {
+               pr_err("Invalid HEADER_CACHE: cnt (%u) > %u\n",
+                      cnt, MAX_CACHE_ENTRIES);
+               return -1;
+       }
+
+       if (ff->size < 2 * sizeof(u32) + cnt * 7 * sizeof(u32)) {
+               pr_err("Invalid HEADER_CACHE: section too small (%zu) for %u entries\n",
+                      ff->size, cnt);
+               return -1;
+       }
+
        caches = calloc(cnt, sizeof(*caches));
        if (!caches)
                return -1;