Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus

* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  Squashfs: update email address
  Squashfs: add extra sanity checks at mount time
  Squashfs: add sanity checks to fragment reading at mount time
  Squashfs: add sanity checks to lookup table reading at mount time
  Squashfs: add sanity checks to id reading at mount time
  Squashfs: add sanity checks to xattr reading at mount time
  Squashfs: reverse order of filesystem table reading
  Squashfs: move table allocation into squashfs_read_table()

1 files changed, 65 insertions, 47 deletions

diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 5c8184c..6f26abe 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -2,7 +2,7 @@
  * Squashfs - a compressed read only filesystem for Linux
  *
  * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
- * Phillip Lougher <phillip@lougher.demon.co.uk>
+ * Phillip Lougher <phillip@squashfs.org.uk>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -83,7 +83,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 	long long root_inode;
 	unsigned short flags;
 	unsigned int fragments;
-	u64 lookup_table_start, xattr_id_table_start;
+	u64 lookup_table_start, xattr_id_table_start, next_table;
 	int err;
 
 	TRACE("Entered squashfs_fill_superblock\n");
@@ -95,12 +95,6 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 	}
 	msblk = sb->s_fs_info;
 
-	sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
-	if (sblk == NULL) {
-		ERROR("Failed to allocate squashfs_super_block\n");
-		goto failure;
-	}
-
 	msblk->devblksize = sb_min_blocksize(sb, BLOCK_SIZE);
 	msblk->devblksize_log2 = ffz(~msblk->devblksize);
 
@@ -114,10 +108,12 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 	 * of bytes_used) we need to set it to an initial sensible dummy value
 	 */
 	msblk->bytes_used = sizeof(*sblk);
-	err = squashfs_read_table(sb, sblk, SQUASHFS_START, sizeof(*sblk));
+	sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk));
 
-	if (err < 0) {
+	if (IS_ERR(sblk)) {
 		ERROR("unable to read squashfs_super_block\n");
+		err = PTR_ERR(sblk);
+		sblk = NULL;
 		goto failed_mount;
 	}
 
@@ -218,18 +214,61 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 		goto failed_mount;
 	}
 
+	/* Handle xattrs */
+	sb->s_xattr = squashfs_xattr_handlers;
+	xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
+	if (xattr_id_table_start == SQUASHFS_INVALID_BLK) {
+		next_table = msblk->bytes_used;
+		goto allocate_id_index_table;
+	}
+
+	/* Allocate and read xattr id lookup table */
+	msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
+		xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
+	if (IS_ERR(msblk->xattr_id_table)) {
+		ERROR("unable to read xattr id index table\n");
+		err = PTR_ERR(msblk->xattr_id_table);
+		msblk->xattr_id_table = NULL;
+		if (err != -ENOTSUPP)
+			goto failed_mount;
+	}
+	next_table = msblk->xattr_table;
+
+allocate_id_index_table:
 	/* Allocate and read id index table */
 	msblk->id_table = squashfs_read_id_index_table(sb,
-		le64_to_cpu(sblk->id_table_start), le16_to_cpu(sblk->no_ids));
+		le64_to_cpu(sblk->id_table_start), next_table,
+		le16_to_cpu(sblk->no_ids));
 	if (IS_ERR(msblk->id_table)) {
+		ERROR("unable to read id index table\n");
 		err = PTR_ERR(msblk->id_table);
 		msblk->id_table = NULL;
 		goto failed_mount;
 	}
+	next_table = msblk->id_table[0];
+
+	/* Handle inode lookup table */
+	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
+	if (lookup_table_start == SQUASHFS_INVALID_BLK)
+		goto handle_fragments;
+
+	/* Allocate and read inode lookup table */
+	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
+		lookup_table_start, next_table, msblk->inodes);
+	if (IS_ERR(msblk->inode_lookup_table)) {
+		ERROR("unable to read inode lookup table\n");
+		err = PTR_ERR(msblk->inode_lookup_table);
+		msblk->inode_lookup_table = NULL;
+		goto failed_mount;
+	}
+	next_table = msblk->inode_lookup_table[0];
 
+	sb->s_export_op = &squashfs_export_ops;
+
+handle_fragments:
 	fragments = le32_to_cpu(sblk->fragments);
 	if (fragments == 0)
-		goto allocate_lookup_table;
+		goto check_directory_table;
 
 	msblk->fragment_cache = squashfs_cache_init("fragment",
 		SQUASHFS_CACHED_FRAGMENTS, msblk->block_size);
@@ -240,45 +279,29 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	/* Allocate and read fragment index table */
 	msblk->fragment_index = squashfs_read_fragment_index_table(sb,
-		le64_to_cpu(sblk->fragment_table_start), fragments);
+		le64_to_cpu(sblk->fragment_table_start), next_table, fragments);
 	if (IS_ERR(msblk->fragment_index)) {
+		ERROR("unable to read fragment index table\n");
 		err = PTR_ERR(msblk->fragment_index);
 		msblk->fragment_index = NULL;
 		goto failed_mount;
 	}
+	next_table = msblk->fragment_index[0];
 
-allocate_lookup_table:
-	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
-	if (lookup_table_start == SQUASHFS_INVALID_BLK)
-		goto allocate_xattr_table;
-
-	/* Allocate and read inode lookup table */
-	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
-		lookup_table_start, msblk->inodes);
-	if (IS_ERR(msblk->inode_lookup_table)) {
-		err = PTR_ERR(msblk->inode_lookup_table);
-		msblk->inode_lookup_table = NULL;
+check_directory_table:
+	/* Sanity check directory_table */
+	if (msblk->directory_table >= next_table) {
+		err = -EINVAL;
 		goto failed_mount;
 	}
 
-	sb->s_export_op = &squashfs_export_ops;
-
-allocate_xattr_table:
-	sb->s_xattr = squashfs_xattr_handlers;
-	xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
-	if (xattr_id_table_start == SQUASHFS_INVALID_BLK)
-		goto allocate_root;
-
-	/* Allocate and read xattr id lookup table */
-	msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
-		xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
-	if (IS_ERR(msblk->xattr_id_table)) {
-		err = PTR_ERR(msblk->xattr_id_table);
-		msblk->xattr_id_table = NULL;
-		if (err != -ENOTSUPP)
-			goto failed_mount;
+	/* Sanity check inode_table */
+	if (msblk->inode_table >= msblk->directory_table) {
+		err = -EINVAL;
+		goto failed_mount;
 	}
-allocate_root:
+
+	/* allocate root */
 	root = new_inode(sb);
 	if (!root) {
 		err = -ENOMEM;
@@ -318,11 +341,6 @@ failed_mount:
 	sb->s_fs_info = NULL;
 	kfree(sblk);
 	return err;
-
-failure:
-	kfree(sb->s_fs_info);
-	sb->s_fs_info = NULL;
-	return -ENOMEM;
 }
 
 
@@ -475,5 +493,5 @@ static const struct super_operations squashfs_super_ops = {
 module_init(init_squashfs_fs);
 module_exit(exit_squashfs_fs);
 MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem");
-MODULE_AUTHOR("Phillip Lougher <phillip@lougher.demon.co.uk>");
+MODULE_AUTHOR("Phillip Lougher <phillip@squashfs.org.uk>");
 MODULE_LICENSE("GPL");