fdtdump.c: make sure size_t argument to memchr is always unsigned.
CID 132817 (#1 of 1): Integer overflowed argument (INTEGER_OVERFLOW)
15. overflow_sink: Overflowed or truncated value (or a value computed from an overflowed or truncated value) endp - p - 4L used as critical argument to function.
Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/fdtdump.c b/fdtdump.c
index 95a6a20..a9a2484 100644
--- a/fdtdump.c
+++ b/fdtdump.c
@@ -15,6 +15,8 @@
#include "util.h"
+#define FDT_MAGIC_SIZE 4
+
#define ALIGN(x, a) (((x) + ((a) - 1)) & ~((a) - 1))
#define PALIGN(p, a) ((void *)(ALIGN((unsigned long)(p), (a))))
#define GET_CELL(p) (p += 4, *((const uint32_t *)(p-4)))
@@ -188,15 +190,15 @@
/* try and locate an embedded fdt in a bigger blob */
if (scan) {
- unsigned char smagic[4];
+ unsigned char smagic[FDT_MAGIC_SIZE];
char *p = buf;
char *endp = buf + len;
fdt_set_magic(smagic, FDT_MAGIC);
/* poor man's memmem */
- while (true) {
- p = memchr(p, smagic[0], endp - p - 4);
+ while ((endp - p) >= FDT_MAGIC_SIZE) {
+ p = memchr(p, smagic[0], endp - p - FDT_MAGIC_SIZE);
if (!p)
break;
if (fdt_magic(p) == FDT_MAGIC) {
@@ -215,7 +217,7 @@
}
++p;
}
- if (!p)
+ if (!p || ((endp - p) < FDT_MAGIC_SIZE))
die("%s: could not locate fdt magic\n", file);
printf("%s: found fdt at offset %#zx\n", file, p - buf);
buf = p;
