From 5ef3961682e5310f2221bae99bcf9f5d0f4b0d51 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 20 Jun 2024 12:32:00 +0100 Subject: [PATCH] btrfs: qgroup: fix quota root leak after quota disable failure [ Upstream commit a7e4c6a3031c74078dba7fa36239d0f4fe476c53 ] If during the quota disable we fail when cleaning the quota tree or when deleting the root from the root tree, we jump to the 'out' label without ever dropping the reference on the quota root, resulting in a leak of the root since fs_info->quota_root is no longer pointing to the root (we have set it to NULL just before those steps). Fix this by always doing a btrfs_put_root() call under the 'out' label. This is a problem that exists since qgroups were first added in 2012 by commit bed92eae26cc ("Btrfs: qgroup implementation and prototypes"), but back then we missed a kfree on the quota root and free_extent_buffer() calls on its root and commit root nodes, since back then roots were not yet reference counted. Reviewed-by: Boris Burkov Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/qgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 80ca7b435b0d..e482889667ec 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1222,7 +1222,7 @@ out: int btrfs_quota_disable(struct btrfs_fs_info *fs_info) { - struct btrfs_root *quota_root; + struct btrfs_root *quota_root = NULL; struct btrfs_trans_handle *trans = NULL; int ret = 0; @@ -1317,9 +1317,9 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info) btrfs_free_tree_block(trans, btrfs_root_id(quota_root), quota_root->node, 0, 1); - btrfs_put_root(quota_root); out: + btrfs_put_root(quota_root); mutex_unlock(&fs_info->qgroup_ioctl_lock); if (ret && trans) btrfs_end_transaction(trans);