[PATCH mtd-utils] misc-utils: fix integer overflow in ftl_check.c

[Anton Moryakov]

Report of the static analyzer:
An integer overflow may occur due to arithmetic operation (multiplication) between variable 'nbam' and value '4' of 'sizeof(u_int)', when 'nbam' is in range 

Corrections explained:
Added robust handling for malloc() failure by checking the returnvalueand providing a clear error message.

Triggers found by static analyzer Svace.

Signed-off-by: Anton Moryakov <ant.v.moryakov at gmail.com>

---
 misc-utils/ftl_check.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/misc-utils/ftl_check.c b/misc-utils/ftl_check.c
index 5b2dae5..fe43a24 100644
--- a/misc-utils/ftl_check.c
+++ b/misc-utils/ftl_check.c
@@ -120,8 +120,17 @@ static void check_partition(int fd)
 
 	/* Create basic block allocation table for control blocks */
 	nbam = (mtd.erasesize >> hdr.BlockSize);
 	bam = malloc(nbam * sizeof(u_int));
+	if (!bam) {
+		perror("malloc failed");
+		return;
+	}

 	for (i = 0; i < le16_to_cpu(hdr.NumEraseUnits); i++) {
 		if (lseek(fd, (i << hdr.EraseUnitSize), SEEK_SET) == -1) {
 			perror("seek failed");
-- 
2.30.2