md/raid1: fix memory leak in raid1_run() if no active rdev

JIRA: https://issues.redhat.com/browse/RHEL-83988

commit 5fbcf76
Author: Zheng Qixing <zhengqixing@huawei.com>
Date:   Sat Feb 15 10:01:37 2025 +0800

    md/raid1: fix memory leak in raid1_run() if no active rdev

    When `raid1_set_limits()` fails or when the array has no active
    `rdev`, the allocated memory for `conf` is not properly freed.

    Add raid1_free() call to properly free the conf in error path.

    Fixes: 799af94 ("md/raid1: don't free conf on raid0_run failure")
    Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
    Link: https://lore.kernel.org/linux-raid/20250215020137.3703757-1-zhengqixing@huaweicloud.com
    Singed-off-by: Yu Kuai <yukuai3@huawei.com>

Signed-off-by: Nigel Croxon <ncroxon@redhat.com>

Author: ncroxon

drivers/md/raid1.c

@@ -46,6 +46,7 @@
 
 static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
 static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
+static void raid1_free(struct mddev *mddev, void *priv);
 
 #define RAID_1_10_NAME "raid1"
 #include "raid1-10.c"
@@ -3252,8 +3253,11 @@ static int raid1_run(struct mddev *mddev)
 
 	if (!mddev_is_dm(mddev)) {
 		ret = raid1_set_limits(mddev);
-		if (ret)
+		if (ret) {
+			if (!mddev->private)
+				raid1_free(mddev, conf);
 			return ret;
+		}
 	}
 
 	mddev->degraded = 0;
@@ -3267,6 +3271,8 @@ static int raid1_run(struct mddev *mddev)
 	 */
 	if (conf->raid_disks - mddev->degraded < 1) {
 		md_unregister_thread(mddev, &conf->thread);
+		if (!mddev->private)
+			raid1_free(mddev, conf);
 		return -EINVAL;
 	}