erofs: fix illegal unmapped accesses in z_erofs_fill_inode_lazy()

Note that we are still accessing 'h_idata_size' and 'h_fragmentoff'
after calling erofs_put_metabuf(), that is not correct. Fix it.

Fixes: ab92184ff8f1 ("erofs: add on-disk compressed tail-packing inline support")
Fixes: b15b2e307c3a ("erofs: support on-disk compressed fragments data")
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20221005013528.62977-1-zbestahu@163.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 44c27ef39c436d2362f530798d259de9c7ec499e..0bb66927e3d0678343da58bbd4aaa5249c1a4980 100644 (file)
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -57,8 +57,7 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 
        pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
                    vi->xattr_isize, 8);
-       kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos),
-                                  EROFS_KMAP_ATOMIC);
+       kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos), EROFS_KMAP);
        if (IS_ERR(kaddr)) {
                err = PTR_ERR(kaddr);
                goto out_unlock;
@@ -73,7 +72,7 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
                vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
                vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63);
                vi->z_tailextent_headlcn = 0;
-               goto unmap_done;
+               goto done;
        }
        vi->z_advise = le16_to_cpu(h->h_advise);
        vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
@@ -85,7 +84,7 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
                erofs_err(sb, "unknown HEAD%u format %u for nid %llu, please upgrade kernel",
                          headnr + 1, vi->z_algorithmtype[headnr], vi->nid);
                err = -EOPNOTSUPP;
-               goto unmap_done;
+               goto out_put_metabuf;
        }
 
        vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7);
@@ -95,7 +94,7 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
                erofs_err(sb, "per-inode big pcluster without sb feature for nid %llu",
                          vi->nid);
                err = -EFSCORRUPTED;
-               goto unmap_done;
+               goto out_put_metabuf;
        }
        if (vi->datalayout == EROFS_INODE_FLAT_COMPRESSION &&
            !(vi->z_advise & Z_EROFS_ADVISE_BIG_PCLUSTER_1) ^
@@ -103,12 +102,8 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
                erofs_err(sb, "big pcluster head1/2 of compact indexes should be consistent for nid %llu",
                          vi->nid);
                err = -EFSCORRUPTED;
-               goto unmap_done;
+               goto out_put_metabuf;
        }
-unmap_done:
-       erofs_put_metabuf(&buf);
-       if (err)
-               goto out_unlock;
 
        if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) {
                struct erofs_map_blocks map = {
@@ -127,7 +122,7 @@ unmap_done:
                        err = -EFSCORRUPTED;
                }
                if (err < 0)
-                       goto out_unlock;
+                       goto out_put_metabuf;
        }
 
        if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER &&
@@ -141,11 +136,14 @@ unmap_done:
                                            EROFS_GET_BLOCKS_FINDTAIL);
                erofs_put_metabuf(&map.buf);
                if (err < 0)
-                       goto out_unlock;
+                       goto out_put_metabuf;
        }
+done:
        /* paired with smp_mb() at the beginning of the function */
        smp_mb();
        set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
+out_put_metabuf:
+       erofs_put_metabuf(&buf);
 out_unlock:
        clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags);
        return err;