blk_revalidate_disk_zones() sizes the zones_cond array from the disk capacity and zone size, but the index used by blk_revalidate_zone_cond() comes from the device-driven report_zones() walk and is never checked against the array size. A device reporting more zones than fit the array makes blk_zone_set_cond() write out of bounds. One way to reach this is a zone count exceeding 32 bits: both blk_revalidate_zone_args.nr_zones and struct zoned_disk_info.nr_zones are unsigned int, so a disk advertising more than UINT_MAX zones (e.g. 2^32 + 1024 zones of one 512-byte logical block) gets its zone count truncated to a small value, undersizing the array while the report walk keeps counting upward. Check the index against the array size before storing the zone condition, and refuse to revalidate when the zone count does not fit 32 bits. Fixes: 6e945ffb6555 ("block: use zone condition to determine conventional zones") Signed-off-by: ZHOU Jiaxiang <26066541r@connect.polyu.hk> Reviewed-by: Damien Le Moal --- block/blk-zoned.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/block/blk-zoned.c b/block/blk-zoned.c index a5afb842b..475aa16bc 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -2018,12 +2018,17 @@ static int disk_revalidate_zone_resources(struct gendisk *disk, struct blk_revalidate_zone_args *args) { struct queue_limits *lim = &disk->queue->limits; + unsigned long long nr_zones; unsigned int pool_size; int ret = 0; args->disk = disk; - args->nr_zones = - DIV_ROUND_UP_ULL(get_capacity(disk), lim->chunk_sectors); + nr_zones = DIV_ROUND_UP_ULL(get_capacity(disk), lim->chunk_sectors); + if (nr_zones > UINT_MAX) { + pr_warn("%s: Too many zones (%llu)\n", disk->disk_name, nr_zones); + return -EINVAL; + } + args->nr_zones = nr_zones; /* Cached zone conditions: 1 byte per zone */ args->zones_cond = kzalloc(args->nr_zones, GFP_NOIO); @@ -2131,6 +2136,12 @@ static int blk_revalidate_zone_cond(struct blk_zone *zone, unsigned int idx, { enum blk_zone_cond cond = zone->cond; + if (idx >= args->nr_zones) { + pr_warn("%s: Zone report index %u exceeds zone count %u\n", + args->disk->disk_name, idx, args->nr_zones); + return -EINVAL; + } + /* Check that the zone condition is consistent with the zone type. */ switch (cond) { case BLK_ZONE_COND_NOT_WP: -- 2.50.1 (Apple Git-155) [https://www.polyu.edu.hk/emaildisclaimer/PolyU_Email_Signature-v2.jpg] Disclaimer: This message (including any attachments) contains confidential information intended for a specific individual and purpose. If you are not the intended recipient, you should delete this message and notify the sender and The Hong Kong Polytechnic University (the University) immediately. Any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited and may be unlawful. The University specifically denies any responsibility for the accuracy or quality of information obtained through University E-mail Facilities. Any views and opinions expressed are only those of the author(s) and do not necessarily represent those of the University and the University accepts no liability whatsoever for any losses or damages incurred or caused to any party as a result of the use of such information. sd_zbc_read_zones() computes the number of zones with 64-bit arithmetic and stores the result in the unsigned int nr_zones field of struct zoned_disk_info, silently truncating counts that exceed 32 bits. The truncated count is later used to size per-zone resources, while the device may still report more zones than fit. Reject such devices at scan time: more than 4 billion zones is not realistic for any medium that exists today, and accepting the truncated count produces inconsistent zone bookkeeping. Signed-off-by: ZHOU Jiaxiang <26066541r@connect.polyu.hk> --- drivers/scsi/sd_zbc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c index 56e455fb5..f4570bd94 100644 --- a/drivers/scsi/sd_zbc.c +++ b/drivers/scsi/sd_zbc.c @@ -589,7 +589,7 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp) int sd_zbc_read_zones(struct scsi_disk *sdkp, struct queue_limits *lim, u8 buf[SD_BUF_SIZE]) { - unsigned int nr_zones; + u64 nr_zones; u32 zone_blocks = 0; int ret; @@ -621,6 +621,12 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, struct queue_limits *lim, goto err; nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks); + if (nr_zones > UINT_MAX) { + sd_printk(KERN_ERR, sdkp, "Too many zones (%llu)\n", + nr_zones); + ret = -EINVAL; + goto err; + } sdkp->early_zone_info.nr_zones = nr_zones; sdkp->early_zone_info.zone_blocks = zone_blocks; -- 2.50.1 (Apple Git-155) [https://www.polyu.edu.hk/emaildisclaimer/PolyU_Email_Signature-v2.jpg] Disclaimer: This message (including any attachments) contains confidential information intended for a specific individual and purpose. If you are not the intended recipient, you should delete this message and notify the sender and The Hong Kong Polytechnic University (the University) immediately. Any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited and may be unlawful. The University specifically denies any responsibility for the accuracy or quality of information obtained through University E-mail Facilities. Any views and opinions expressed are only those of the author(s) and do not necessarily represent those of the University and the University accepts no liability whatsoever for any losses or damages incurred or caused to any party as a result of the use of such information.