Commit 9bf3d203 authored by Zhang Yi's avatar Zhang Yi Committed by Jan Kara
Browse files

quota: check block number when reading the block in quota file 

The block number in the quota tree on disk should be smaller than the
v2_disk_dqinfo.dqi_blocks. If the quota file was corrupted, we may be
allocating an 'allocated' block and that would lead to a loop in a tree,
which will probably trigger oops later. This patch adds a check for the
block number in the quota tree to prevent such potential issue.

Link: https://lore.kernel.org/r/20211008093821.1001186-2-yi.zhang@huawei.com


Signed-off-by: default avatarZhang Yi <yi.zhang@huawei.com>
Cc: stable@kernel.org
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 64570fbc

fs/quota/quota_tree.c

+14 −0
Original line number Diff line number Diff line
@@ -479,6 +479,13 @@ static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot, 
		goto out_buf;

	}

	newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);

	if (newblk < QT_TREEOFF || newblk >= info->dqi_blocks) {

		quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)",

			    newblk, info->dqi_blocks);

		ret = -EUCLEAN;

		goto out_buf;

	}



	if (depth == info->dqi_qtree_depth - 1) {

		ret = free_dqentry(info, dquot, newblk);

		newblk = 0;
@@ -578,6 +585,13 @@ static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info, 
	blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);

	if (!blk)	/* No reference? */

		goto out_buf;

	if (blk < QT_TREEOFF || blk >= info->dqi_blocks) {

		quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)",

			    blk, info->dqi_blocks);

		ret = -EUCLEAN;

		goto out_buf;

	}



	if (depth < info->dqi_qtree_depth - 1)

		ret = find_tree_dqentry(info, dquot, blk, depth+1);

	else