fs: fat: fix set_cluster()
Avoid CoverityScan warning SIGN_EXTENSION by changing the type of
parameter size of set_cluster().
Avoid leaking stack content when writing an incomplete last sector.
Reported-by: Coverity (CID: 184096)
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 1ec72d1..9fcf3bc 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -387,16 +387,22 @@
return next_entry;
}
-/*
- * Write at most 'size' bytes from 'buffer' into the specified cluster.
- * Return 0 on success, -1 otherwise.
+/**
+ * set_cluster() - write data to cluster
+ *
+ * Write 'size' bytes from 'buffer' into the specified cluster.
+ *
+ * @mydata: data to be written
+ * @clustnum: cluster to be written to
+ * @buffer: data to be written
+ * @size: bytes to be written (but not more than the size of a cluster)
+ * Return: 0 on success, -1 otherwise
*/
static int
-set_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer,
- unsigned long size)
+set_cluster(fsdata *mydata, u32 clustnum, u8 *buffer, u32 size)
{
- __u32 idx = 0;
- __u32 startsect;
+ u32 idx = 0;
+ u32 startsect;
int ret;
if (clustnum > 0)
@@ -438,7 +444,8 @@
if (size) {
ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
-
+ /* Do not leak content of stack */
+ memset(tmpbuf, 0, mydata->sect_size);
memcpy(tmpbuf, buffer, size);
ret = disk_write(startsect, 1, tmpbuf);
if (ret != 1) {
@@ -872,7 +879,7 @@
/* set remaining bytes */
actsize = filesize;
- if (set_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
+ if (set_cluster(mydata, curclust, buffer, (u32)actsize) != 0) {
debug("error: writing cluster\n");
return -1;
}
@@ -889,7 +896,7 @@
return 0;
getit:
- if (set_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
+ if (set_cluster(mydata, curclust, buffer, (u32)actsize) != 0) {
debug("error: writing cluster\n");
return -1;
}