Commit e11247a9 authored by Filipe Manana's avatar Filipe Manana Committed by Wang Zhaolong
Browse files

btrfs: qgroup: fix quota root leak after quota disable failure 

stable inclusion
from stable-v5.10.223
commit 94818bdb00ef34a996a06aa63d11f591074cb757
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEN9
CVE: CVE-2024-41078

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=94818bdb00ef34a996a06aa63d11f591074cb757



--------------------------------

[ 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 bed92eae ("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: default avatarBoris Burkov <boris@bur.io>
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarWang Zhaolong <wangzhaolong1@huawei.com>
parent e81a12ab

fs/btrfs/qgroup.c

+2 −2
Original line number Diff line number Diff line
@@ -1197,7 +1197,7 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info) 


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;
@@ -1290,9 +1290,9 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info) 
	btrfs_tree_unlock(quota_root->node);

	btrfs_free_tree_block(trans, 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);