From: Jeff Mahoney <jeffm@xxxxxxxx>
A particular fsfuzzer run caused an hfs file system to crash on mount. This
is due to a corrupted MDB extent record causing a miscalculation of
HFSPLUS_I(inode)->first_blocks for the extent tree. If the extent records
are zereod out, then it won't trigger the first_blocks special case and
instead falls through to the extent code, which we're in the middle
of initializing.
This patch catches the 0 size extent records, reports the corruption,
and fails the mount.
[hch: ported of commit 47f365eb575735c6b2edf5d08e0d16d26a9c23bd from hfs]
Reported-by: Ramon de Carvalho Valle <rcvalle@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxxxxxx>
Index: linux-2.6/fs/hfsplus/btree.c
===================================================================
--- linux-2.6.orig/fs/hfsplus/btree.c 2010-10-01 16:52:32.362010219 +0200
+++ linux-2.6/fs/hfsplus/btree.c 2010-10-01 16:53:49.328291422 +0200
@@ -39,10 +39,16 @@ struct hfs_btree *hfs_btree_open(struct
goto free_tree;
tree->inode = inode;
+ if (!HFSPLUS_I(tree->inode)->first_blocks) {
+ printk(KERN_ERR
+ "hfs: invalid btree extent records (0 size).\n");
+ goto free_inode;
+ }
+
mapping = tree->inode->i_mapping;
page = read_mapping_page(mapping, 0, NULL);
if (IS_ERR(page))
- goto free_tree;
+ goto free_inode;
/* Load the header */
head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
@@ -89,8 +95,9 @@ struct hfs_btree *hfs_btree_open(struct
fail_page:
tree->inode->i_mapping->a_ops = &hfsplus_aops;
page_cache_release(page);
- free_tree:
+ free_inode:
iput(tree->inode);
+ free_tree:
kfree(tree);
return NULL;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
