Commit 1a5223c1 authored by Chao Yu's avatar Chao Yu Committed by Gao Xiang
Browse files

erofs: do sanity check on m->type in z_erofs_load_compact_lcluster() 



All below functions will do sanity check on m->type, let's move sanity
check to z_erofs_load_compact_lcluster() for cleanup.
- z_erofs_map_blocks_fo
- z_erofs_get_extent_compressedlen
- z_erofs_get_extent_decompressedlen
- z_erofs_extent_lookback

Reviewed-by: default avatarHongbo Li <lihongbo22@huawei.com>
Signed-off-by: default avatarChao Yu <chao@kernel.org>
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250708110928.3110375-1-chao@kernel.org


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 96debe8c

fs/erofs/zmap.c

+41 −62
Original line number Diff line number Diff line
@@ -240,6 +240,13 @@ static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m, 
static int z_erofs_load_lcluster_from_disk(struct z_erofs_maprecorder *m,

					   unsigned int lcn, bool lookahead)

{

	if (m->type >= Z_EROFS_LCLUSTER_TYPE_MAX) {

		erofs_err(m->inode->i_sb, "unknown type %u @ lcn %u of nid %llu",

				m->type, lcn, EROFS_I(m->inode)->nid);

		DBG_BUGON(1);

		return -EOPNOTSUPP;

	}



	switch (EROFS_I(m->inode)->datalayout) {

	case EROFS_INODE_COMPRESSED_FULL:

		return z_erofs_load_full_lcluster(m, lcn);
@@ -265,12 +272,7 @@ static int z_erofs_extent_lookback(struct z_erofs_maprecorder *m, 
		if (err)

			return err;



		if (m->type >= Z_EROFS_LCLUSTER_TYPE_MAX) {

			erofs_err(sb, "unknown type %u @ lcn %lu of nid %llu",

				  m->type, lcn, vi->nid);

			DBG_BUGON(1);

			return -EOPNOTSUPP;

		} else if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {

		if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {

			lookback_distance = m->delta[0];

			if (!lookback_distance)

				break;
@@ -325,25 +327,18 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m, 
	DBG_BUGON(lcn == initial_lcn &&

		  m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD);



	if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {

		if (m->delta[0] != 1) {

	if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD && m->delta[0] != 1) {

		erofs_err(sb, "bogus CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid);

		DBG_BUGON(1);

		return -EFSCORRUPTED;

	}

		if (m->compressedblks)

			goto out;

	} else if (m->type < Z_EROFS_LCLUSTER_TYPE_MAX) {



	/*

		 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type

		 * rather than CBLKCNT, it's a 1 block-sized pcluster.

	 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type rather

	 * than CBLKCNT, it's a 1 block-sized pcluster.

	 */

	if (m->type != Z_EROFS_LCLUSTER_TYPE_NONHEAD || !m->compressedblks)

		m->compressedblks = 1;

		goto out;

	}

	erofs_err(sb, "cannot found CBLKCNT @ lcn %lu of nid %llu", lcn, vi->nid);

	DBG_BUGON(1);

	return -EFSCORRUPTED;

out:

	m->map->m_plen = erofs_pos(sb, m->compressedblks);

	return 0;
@@ -379,11 +374,6 @@ static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m) 
			if (lcn != headlcn)

				break;	/* ends at the next HEAD lcluster */

			m->delta[1] = 1;

		} else {

			erofs_err(inode->i_sb, "unknown type %u @ lcn %llu of nid %llu",

				  m->type, lcn, vi->nid);

			DBG_BUGON(1);

			return -EOPNOTSUPP;

		}

		lcn += m->delta[1];

	}
@@ -428,11 +418,7 @@ static int z_erofs_map_blocks_fo(struct inode *inode, 
	map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED;

	end = (m.lcn + 1ULL) << lclusterbits;



	switch (m.type) {

	case Z_EROFS_LCLUSTER_TYPE_PLAIN:

	case Z_EROFS_LCLUSTER_TYPE_HEAD1:

	case Z_EROFS_LCLUSTER_TYPE_HEAD2:

		if (endoff >= m.clusterofs) {

	if (m.type != Z_EROFS_LCLUSTER_TYPE_NONHEAD && endoff >= m.clusterofs) {

		m.headtype = m.type;

		map->m_la = (m.lcn << lclusterbits) | m.clusterofs;

		/*
@@ -442,8 +428,8 @@ static int z_erofs_map_blocks_fo(struct inode *inode, 
		 */

		if (ztailpacking && end > inode->i_size)

			end = inode->i_size;

			break;

		}

	} else {

		if (m.type != Z_EROFS_LCLUSTER_TYPE_NONHEAD) {

			/* m.lcn should be >= 1 if endoff < m.clusterofs */

			if (!m.lcn) {

				erofs_err(sb, "invalid logical cluster 0 at nid %llu",
@@ -454,18 +440,11 @@ static int z_erofs_map_blocks_fo(struct inode *inode, 
			end = (m.lcn << lclusterbits) | m.clusterofs;

			map->m_flags |= EROFS_MAP_FULL_MAPPED;

			m.delta[0] = 1;

		fallthrough;

	case Z_EROFS_LCLUSTER_TYPE_NONHEAD:

		}

		/* get the corresponding first chunk */

		err = z_erofs_extent_lookback(&m, m.delta[0]);

		if (err)

			goto unmap_out;

		break;

	default:

		erofs_err(sb, "unknown type %u @ offset %llu of nid %llu",

			  m.type, ofs, vi->nid);

		err = -EOPNOTSUPP;

		goto unmap_out;

	}

	if (m.partialref)

		map->m_flags |= EROFS_MAP_PARTIAL_REF;