[PATCH 4.14 01/41] scsi: sd_zbc: Fix potential memory leak

From: Greg Kroah-Hartman
Date: Sat Jun 09 2018 - 11:44:00 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Damien Le Moal <damien.lemoal@xxxxxxx>

commit 4b433924b2755a94f99258c178684a0e05c344de upstream.

Rework sd_zbc_check_zone_size() to avoid a memory leak due to an early
return if sd_zbc_report_zones() fails.

Reported-by: David.butterfield <david.butterfield@xxxxxxx>
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/scsi/sd_zbc.c | 34 +++++++++++++++-------------------
1 file changed, 15 insertions(+), 19 deletions(-)

--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -425,7 +425,7 @@ static int sd_zbc_check_capacity(struct

static int sd_zbc_check_zone_size(struct scsi_disk *sdkp)
{
- u64 zone_blocks;
+ u64 zone_blocks = 0;
sector_t block = 0;
unsigned char *buf;
unsigned char *rec;
@@ -443,10 +443,8 @@ static int sd_zbc_check_zone_size(struct

/* Do a report zone to get the same field */
ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0);
- if (ret) {
- zone_blocks = 0;
- goto out;
- }
+ if (ret)
+ goto out_free;

same = buf[4] & 0x0f;
if (same > 0) {
@@ -489,7 +487,7 @@ static int sd_zbc_check_zone_size(struct
ret = sd_zbc_report_zones(sdkp, buf,
SD_ZBC_BUF_SIZE, block);
if (ret)
- return ret;
+ goto out_free;
}

} while (block < sdkp->capacity);
@@ -497,34 +495,32 @@ static int sd_zbc_check_zone_size(struct
zone_blocks = sdkp->zone_blocks;

out:
- kfree(buf);
-
if (!zone_blocks) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"Devices with non constant zone "
"size are not supported\n");
- return -ENODEV;
- }
-
- if (!is_power_of_2(zone_blocks)) {
+ ret = -ENODEV;
+ } else if (!is_power_of_2(zone_blocks)) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"Devices with non power of 2 zone "
"size are not supported\n");
- return -ENODEV;
- }
-
- if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
+ ret = -ENODEV;
+ } else if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"Zone size too large\n");
- return -ENODEV;
+ ret = -ENODEV;
+ } else {
+ sdkp->zone_blocks = zone_blocks;
+ sdkp->zone_shift = ilog2(zone_blocks);
}

- sdkp->zone_blocks = zone_blocks;
+out_free:
+ kfree(buf);

- return 0;
+ return ret;
}

static int sd_zbc_setup(struct scsi_disk *sdkp)