Commit c346c629 authored by Fedor Pchelkin's avatar Fedor Pchelkin Committed by David Sterba
Browse files

btrfs: qgroup: don't use extent changeset when not needed 



The local extent changeset is passed to clear_record_extent_bits() where
it may have some additional memory dynamically allocated for ulist. When
qgroup is disabled, the memory is leaked because in this case the
changeset is not released upon __btrfs_qgroup_release_data() return.

Since the recorded contents of the changeset are not used thereafter, just
don't pass it.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Reported-by: default avatar <syzbot+81670362c283f3dd889c@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/lkml/000000000000aa8c0c060ade165e@google.com


Fixes: af0e2aab ("btrfs: qgroup: flush reservations during quota disable")
CC: stable@vger.kernel.org # 6.10+
Reviewed-by: default avatarBoris Burkov <boris@bur.io>
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarFedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent ecb54277

fs/btrfs/qgroup.c

+1 −2
Original line number Diff line number Diff line
@@ -4346,10 +4346,9 @@ static int __btrfs_qgroup_release_data(struct btrfs_inode *inode, 
	int ret;



	if (btrfs_qgroup_mode(inode->root->fs_info) == BTRFS_QGROUP_MODE_DISABLED) {

		extent_changeset_init(&changeset);

		return clear_record_extent_bits(&inode->io_tree, start,

						start + len - 1,

						EXTENT_QGROUP_RESERVED, &changeset);

						EXTENT_QGROUP_RESERVED, NULL);

	}



	/* In release case, we shouldn't have @reserved */