[PATCH V2 14/14] perf tools: Validate that mmap_pages is not too big

[Adrian Hunter]

Amend perf_evlist__parse_mmap_pages() to check that
the mmap_pages entered via the --mmap_pages/-m
option is not too big.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 tools/perf/util/evlist.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 9d17998..9d6d01c 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -725,7 +725,8 @@ static size_t perf_evlist__mmap_size(unsigned long pages)
 int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
 				  int unset __maybe_unused)
 {
-	unsigned int pages, val, *mmap_pages = opt->value;
+	unsigned int *mmap_pages = opt->value;
+	unsigned long pages, val;
 	size_t size;
 	static struct parse_tag tags[] = {
 		{ .tag  = 'B', .mult = 1       },
@@ -736,12 +737,12 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
 	};
 
 	val = parse_tag_value(str, tags);
-	if (val != (unsigned int) -1) {
+	if (val != (unsigned long) -1) {
 		/* we got file size value */
 		pages = PERF_ALIGN(val, page_size) / page_size;
-		if (!is_power_of_2(pages)) {
+		if (pages < (1UL << 31) && !is_power_of_2(pages)) {
 			pages = next_pow2(pages);
-			pr_info("rounding mmap pages size to %u (%u pages)\n",
+			pr_info("rounding mmap pages size to %lu (%lu pages)\n",
 				pages * page_size, pages);
 		}
 	} else {
@@ -754,6 +755,11 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
 		}
 	}
 
+	if (pages > UINT_MAX || pages > SIZE_MAX / page_size) {
+		pr_err("--mmap_pages/-m value too big\n");
+		return -1;
+	}
+
 	size = perf_evlist__mmap_size(pages);
 	if (!size) {
 		pr_err("--mmap_pages/-m value must be a power of two.");
-- 
1.7.11.7

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