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From:   Zixuan Fu <r33s3n6@gmail.com>
To:     clm@fb.com, josef@toxicpanda.com, dsterba@suse.com
Cc:     linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org,
        baijiaju1990@gmail.com, Zixuan Fu <r33s3n6@gmail.com>,
        TOTE Robot <oslab@tsinghua.edu.cn>
Subject: [PATCH] fs: btrfs: fix possible memory leaks in btrfs_get_dev_args_from_path()
Date:   Mon, 15 Aug 2022 23:16:06 +0800
Message-Id: <20220815151606.3479183-1-r33s3n6@gmail.com>
MIME-Version: 1.0
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In btrfs_get_dev_args_from_path(), btrfs_get_bdev_and_sb() can fail if the
path is invalid. In this case, btrfs_get_dev_args_from_path() returns
directly without freeing args->uuid and args->fsid allocated before, which
causes memory leaks.

To fix these possible leaks, when btrfs_get_bdev_and_sb() fails, 
btrfs_put_dev_args_from_path() is called to clean up the memory.

Fixes: faa775c41d655 ("btrfs: add a btrfs_get_dev_args_from_path helper")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Zixuan Fu <r33s3n6@gmail.com>
---
 fs/btrfs/volumes.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 272901514b0c..064ab2a79c80 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2345,8 +2345,11 @@ int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
 
 	ret = btrfs_get_bdev_and_sb(path, FMODE_READ, fs_info->bdev_holder, 0,
 				    &bdev, &disk_super);
-	if (ret)
+	if (ret) {
+		btrfs_put_dev_args_from_path(args);
 		return ret;
+	}
+
 	args->devid = btrfs_stack_device_id(&disk_super->dev_item);
 	memcpy(args->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE);
 	if (btrfs_fs_incompat(fs_info, METADATA_UUID))
-- 
2.25.1