[PATCH 1/2] block: fix zones_cond memory leak in blk_revalidate_disk_zones()

[Jackie Liu <liu.yun@linux.dev>]

From: Jackie Liu <liuyun01@kylinos.cn>

Fix memory leaks of args.zones_cond allocated in
disk_revalidate_zone_resources() on multiple error paths:

1) When disk_revalidate_zone_resources() itself fails (e.g.
   disk_alloc_zone_resources() returns an error), blk_revalidate_disk_zones()
   returns directly without freeing args.zones_cond.

2) When report_zones() fails or the capacity check fails,
   disk_free_zone_resources() only frees the old disk->zones_cond, not
   the newly allocated args.zones_cond.

3) When the nr_conv_zones validation fails in disk_update_zone_resources(),
   the code jumps to unfreeze before disk_set_zones_cond_array() transfers
   ownership of args->zones_cond to disk->zones_cond.

Fix cases 1 and 2 by adding a free_zones_cond label at the end of
blk_revalidate_disk_zones() to centralize the cleanup. Fix case 3 by
moving disk_set_zones_cond_array() before the nr_conv_zones check in
disk_update_zone_resources() so that ownership is transferred early and
disk_free_zone_resources() at the unfreeze label properly frees it.

Fixes: 6e945ffb6555 ("block: use zone condition to determine conventional zones")
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
---
 block/blk-zoned.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 9d1dd6ccfad7..2ea790e4f320 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -1956,6 +1956,8 @@ static int disk_update_zone_resources(struct gendisk *disk,
 	memflags = blk_mq_freeze_queue(q);
 
 	disk->nr_zones = args->nr_zones;
+	disk_set_zones_cond_array(disk, args->zones_cond);
+
 	if (args->nr_conv_zones >= disk->nr_zones) {
 		queue_limits_cancel_update(q);
 		pr_warn("%s: Invalid number of conventional zones %u / %u\n",
@@ -1966,7 +1968,6 @@ static int disk_update_zone_resources(struct gendisk *disk,
 
 	disk->zone_capacity = args->zone_capacity;
 	disk->last_zone_capacity = args->last_zone_capacity;
-	disk_set_zones_cond_array(disk, args->zones_cond);
 
 	/*
 	 * Some devices can advertise zone resource limits that are larger than
@@ -2239,7 +2240,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 	ret = disk_revalidate_zone_resources(disk, &args);
 	if (ret) {
 		memalloc_noio_restore(noio_flag);
-		return ret;
+		goto free_zones_cond;
 	}
 
 	ret = disk->fops->report_zones(disk, 0, UINT_MAX, &rep_args);
@@ -2268,6 +2269,8 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 	disk_free_zone_resources(disk);
 	blk_mq_unfreeze_queue(q, memflags);
 
+free_zones_cond:
+	kfree(args.zones_cond);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);
-- 
2.51.1