lmkd: Protect against buffer overflow
We're passing a 'line' whose backing buffer is PAGE_MAX in size
into memory_stat_parse_line(). We protect overflowing the smaller
LINE_MAX 'key' buffer via some C preprocessing macros to assure
we limit the size.
Test: Local build with LMKD_LOG_STATS set for this file.
Bug: 76220622
Merged-In: I9e50d4270f7099e37a9bfc7fb9b9b95cc7adb086
Change-Id: I9e50d4270f7099e37a9bfc7fb9b9b95cc7adb086
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index e2e5c4e..ee2f343 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -75,6 +75,9 @@
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
#define EIGHT_MEGA (1 << 23)
+#define STRINGIFY(x) STRINGIFY_INTERNAL(x)
+#define STRINGIFY_INTERNAL(x) #x
+
/* default to old in-kernel interface if no memory pressure events */
static int use_inkernel_interface = 1;
static bool has_inkernel_module;
@@ -555,10 +558,10 @@
#ifdef LMKD_LOG_STATS
static void memory_stat_parse_line(char *line, struct memory_stat *mem_st) {
- char key[LINE_MAX];
+ char key[LINE_MAX + 1];
int64_t value;
- sscanf(line,"%s %" SCNd64 "", key, &value);
+ sscanf(line, "%" STRINGIFY(LINE_MAX) "s %" SCNd64 "", key, &value);
if (strcmp(key, "total_") < 0) {
return;