Commit 47f365eb authored Oct 26, 2009 by Jeff Mahoney Committed by Linus Torvalds Oct 29, 2009

hfs: fix oops on mount with corrupted btree extent records



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
HFS_I(inode)->first_blocks for the extent tree.  If the extent records are
zereod out, it won't trigger the first_blocks special case.  Instead it
falls through to the extent code which we're still in the middle of
initializing.

This patch catches the 0 size extent records, reports the corruption, and
fails the mount.

Reported-by: Ramon de Carvalho Valle <rcvalle@linux.vnet.ibm.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent cf6e6932

fs/hfs/btree.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,11 @@ struct hfs_btree hfs_btree_open(struct super_block sb, u32 id, btree_keycmp ke
		}
		unlock_new_inode(tree->inode);

		if (!HFS_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))

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