From: Zhang Yi <yi.zhang@xxxxxxxxxx> commit 9bf3d20331295b1ecb81f4ed9ef358c51699a050 upstream. 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@xxxxxxxxxx Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/quota/quota_tree.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/fs/quota/quota_tree.c +++ b/fs/quota/quota_tree.c @@ -487,6 +487,13 @@ static int remove_tree(struct qtree_mem_ 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; @@ -586,6 +593,13 @@ static loff_t find_tree_dqentry(struct q 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
