Commit 30c4fdc3 authored by Damien Le Moal's avatar Damien Le Moal Committed by Martin K. Petersen
Browse files

scsi: sd_zbc: Prevent zone information memory leak 

Make sure to always free a scsi disk zone information, even for regular
disks. This ensures that there is no memory leak, even in the case of a
zoned disk changing type to a regular disk (e.g. with a reformat using the
FORMAT WITH PRESET command or other vendor proprietary command).

To do this, rename sd_zbc_clear_zone_info() to sd_zbc_free_zone_info() and
remove sd_zbc_release_disk(). A call to sd_zbc_free_zone_info() is added to
sd_zbc_read_zones() for drives for which sd_is_zoned() returns
false. Furthermore, sd_zbc_free_zone_info() code make s sure that the sdkp
rev_mutex is never used while not being initialized by gating the cleanup
code with a a check on the zone_wp_update_buf field as it is never NULL
when rev_mutex has been initialized.

Link: https://lore.kernel.org/r/20220601062544.905141-3-damien.lemoal@opensource.wdc.com


Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDamien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 05fbde3a

drivers/scsi/sd.c

+1 −1
Original line number Diff line number Diff line
@@ -3580,7 +3580,7 @@ static void scsi_disk_release(struct device *dev) 
	struct scsi_disk *sdkp = to_scsi_disk(dev);



	ida_free(&sd_index_ida, sdkp->index);

	sd_zbc_release_disk(sdkp);

	sd_zbc_free_zone_info(sdkp);

	put_device(&sdkp->device->sdev_gendev);

	free_opal_dev(sdkp->opal_dev);

drivers/scsi/sd.h

+2 −2
Original line number Diff line number Diff line
@@ -241,7 +241,7 @@ static inline int sd_is_zoned(struct scsi_disk *sdkp) 


#ifdef CONFIG_BLK_DEV_ZONED



void sd_zbc_release_disk(struct scsi_disk *sdkp);

void sd_zbc_free_zone_info(struct scsi_disk *sdkp);

int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]);

int sd_zbc_revalidate_zones(struct scsi_disk *sdkp);

blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
@@ -256,7 +256,7 @@ blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd, sector_t *lba, 


#else /* CONFIG_BLK_DEV_ZONED */



static inline void sd_zbc_release_disk(struct scsi_disk *sdkp) {}

static inline void sd_zbc_free_zone_info(struct scsi_disk *sdkp) {}



static inline int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE])

{

drivers/scsi/sd_zbc.c

+13 −13
Original line number Diff line number Diff line
@@ -786,8 +786,11 @@ static int sd_zbc_init_disk(struct scsi_disk *sdkp) 
	return 0;

}



static void sd_zbc_clear_zone_info(struct scsi_disk *sdkp)

void sd_zbc_free_zone_info(struct scsi_disk *sdkp)

{

	if (!sdkp->zone_wp_update_buf)

		return;



	/* Serialize against revalidate zones */

	mutex_lock(&sdkp->rev_mutex);
@@ -802,12 +805,6 @@ static void sd_zbc_clear_zone_info(struct scsi_disk *sdkp) 
	mutex_unlock(&sdkp->rev_mutex);

}



void sd_zbc_release_disk(struct scsi_disk *sdkp)

{

	if (sd_is_zoned(sdkp))

		sd_zbc_clear_zone_info(sdkp);

}



static void sd_zbc_revalidate_zones_cb(struct gendisk *disk)

{

	struct scsi_disk *sdkp = scsi_disk(disk);
@@ -914,12 +911,15 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]) 
	u32 zone_blocks = 0;

	int ret;



	if (!sd_is_zoned(sdkp))

	if (!sd_is_zoned(sdkp)) {

		/*

		 * Device managed or normal SCSI disk,

		 * no special handling required

		 * Device managed or normal SCSI disk, no special handling

		 * required. Nevertheless, free the disk zone information in

		 * case the device type changed.

		 */

		sd_zbc_free_zone_info(sdkp);

		return 0;

	}



	/* READ16/WRITE16 is mandatory for ZBC disks */

	sdkp->device->use_16_for_rw = 1;
@@ -928,11 +928,11 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]) 
	if (!blk_queue_is_zoned(q)) {

		/*

		 * This can happen for a host aware disk with partitions.

		 * The block device zone information was already cleared

		 * by blk_queue_set_zoned(). Only clear the scsi disk zone

		 * The block device zone model was already cleared by

		 * blk_queue_set_zoned(). Only free the scsi disk zone

		 * information and exit early.

		 */

		sd_zbc_clear_zone_info(sdkp);

		sd_zbc_free_zone_info(sdkp);

		return 0;

	}