Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
erofs: error out obviously illegal extents in advance
Detect some corrupted extent cases during metadata parsing rather
than letting them result in harmless decompression failures later:
- For full-reference compressed extents, the compressed size must
not exceed the decompressed size, which is a strict on-disk
layout constraint;
- For plain (shifted/interlaced) extents, the decoded size must
not exceed the encoded size, even accounting for partial decoding.
Both ways work but it should be better to report illegal extents as
metadata layout violations rather than deferring as decompression
failure.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
+15
-10
-1
fs/erofs/decompressor.c
-1
fs/erofs/decompressor.c
···
145
145
oend = rq->pageofs_out + rq->outputsize;
146
146
omargin = PAGE_ALIGN(oend) - oend;
147
147
if (!rq->partial_decoding && may_inplace &&
148
-
rq->outpages >= rq->inpages &&
149
148
omargin >= LZ4_DECOMPRESS_INPLACE_MARGIN(rq->inputsize)) {
150
149
for (i = 0; i < rq->inpages; ++i)
151
150
if (rq->out[rq->outpages - rq->inpages + i] !=
+15
-9
fs/erofs/zmap.c
+15
-9
fs/erofs/zmap.c
···
473
473
}
474
474
475
475
if (m.headtype == Z_EROFS_LCLUSTER_TYPE_PLAIN) {
476
-
if (map->m_llen > map->m_plen) {
477
-
DBG_BUGON(1);
478
-
err = -EFSCORRUPTED;
479
-
goto unmap_out;
480
-
}
481
476
if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER)
482
477
map->m_algorithmformat = Z_EROFS_COMPRESSION_INTERLACED;
483
478
else
···
715
720
map->m_algorithmformat, map->m_la, EROFS_I(inode)->nid);
716
721
return -EOPNOTSUPP;
717
722
}
718
-
if (unlikely(map->m_algorithmformat < Z_EROFS_COMPRESSION_MAX &&
719
-
!(sbi->available_compr_algs & (1 << map->m_algorithmformat)))) {
720
-
erofs_err(inode->i_sb, "inconsistent algorithmtype %u for nid %llu",
721
-
map->m_algorithmformat, EROFS_I(inode)->nid);
723
+
724
+
if (map->m_algorithmformat < Z_EROFS_COMPRESSION_MAX) {
725
+
if (sbi->available_compr_algs ^ BIT(map->m_algorithmformat)) {
726
+
erofs_err(inode->i_sb, "inconsistent algorithmtype %u for nid %llu",
727
+
map->m_algorithmformat, EROFS_I(inode)->nid);
728
+
return -EFSCORRUPTED;
729
+
}
730
+
if (EROFS_MAP_FULL(map->m_flags) && map->m_llen < map->m_plen) {
731
+
erofs_err(inode->i_sb, "too much compressed data @ la %llu of nid %llu",
732
+
map->m_la, EROFS_I(inode)->nid);
733
+
return -EFSCORRUPTED;
734
+
}
735
+
} else if (map->m_llen > map->m_plen) {
736
+
erofs_err(inode->i_sb, "not enough plain data on disk @ la %llu of nid %llu",
737
+
map->m_la, EROFS_I(inode)->nid);
722
738
return -EFSCORRUPTED;
723
739
}
724
740
if (unlikely(map->m_plen > Z_EROFS_PCLUSTER_MAX_SIZE ||