Import revision 4b0089abdf36a27fda364b25e95706a0abfe6c3a from FreeBSD.
Change-Id: Ib131afe8f995a1847f2f8090c62b288177f6c23b
diff --git a/dir.c b/dir.c
index 6bdc3b4..018250a 100644
--- a/dir.c
+++ b/dir.c
@@ -388,7 +388,8 @@
checksize(struct fat_descriptor *fat, u_char *p, struct dosDirEntry *dir)
{
int ret = FSOK;
- size_t physicalSize;
+ size_t chainsize;
+ u_int64_t physicalSize;
struct bootblock *boot;
boot = fat_get_boot(fat);
@@ -401,9 +402,9 @@
} else {
if (!fat_is_valid_cl(fat, dir->head))
return FSERROR;
- ret = checkchain(fat, dir->head, &physicalSize);
+ ret = checkchain(fat, dir->head, &chainsize);
/*
- * Upon return, physicalSize would hold the chain length
+ * Upon return, chainsize would hold the chain length
* that checkchain() was able to validate, but if the user
* refused the proposed repair, it would be unsafe to
* proceed with directory entry fix, so bail out in that
@@ -412,7 +413,13 @@
if (ret == FSERROR) {
return (FSERROR);
}
- physicalSize *= boot->ClusterSize;
+ /*
+ * The maximum file size on FAT32 is 4GiB - 1, which
+ * will occupy a cluster chain of exactly 4GiB in
+ * size. On 32-bit platforms, since size_t is 32-bit,
+ * it would wrap back to 0.
+ */
+ physicalSize = (u_int64_t)chainsize * boot->ClusterSize;
}
if (physicalSize < dir->size) {
pwarn("size of %s is %u, should at most be %zu\n",
