[PATCH v3] usb-storage: Check whether divisors are non-zero

[Shichao Lai]

Since uzonesize may be zero, so checks for non-zero
are necessary in two places of alauda.c.

Reported-by: xingwei lee <xrivendell7@xxxxxxxxx>
Reported-by: yue sun <samsun1006219@xxxxxxxxx>
Signed-off-by: Shichao Lai <shichaorai@xxxxxxxxx>
---
Changes since v1:
- Add one more check in alauda_write_lba().
- Move check ahead of loop in alauda_read_data().
- Change the order of variable list in alauda_write_lba().

 drivers/usb/storage/alauda.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c
index 115f05a6201a..ebef1a8a7ca4 100644
--- a/drivers/usb/storage/alauda.c
+++ b/drivers/usb/storage/alauda.c
@@ -816,8 +816,10 @@ static int alauda_write_lba(struct us_data *us, u16 lba,
 	unsigned int zonesize = MEDIA_INFO(us).zonesize;
 	unsigned int pagesize = MEDIA_INFO(us).pagesize;
 	unsigned int blocksize = MEDIA_INFO(us).blocksize;
-	unsigned int lba_offset = lba % uzonesize;
 	unsigned int new_pba_offset;
+	if (!uzonesize)
+		return USB_STOR_TRANSPORT_ERROR;
+	unsigned int lba_offset = lba % uzonesize;
 	unsigned int zone = lba / uzonesize;
 
 	alauda_ensure_map_for_zone(us, zone);
@@ -923,6 +925,8 @@ static int alauda_read_data(struct us_data *us, unsigned long address,
 	unsigned int uzonesize = MEDIA_INFO(us).uzonesize;
 	struct scatterlist *sg;
 	int result;
+	if (!uzonesize)
+		return USB_STOR_TRANSPORT_ERROR;
 
 	/*
 	 * Since we only read in one block at a time, we have to create
-- 
2.34.1