linux-kernel - [PATCH] hfs: fix oops on mount with corrupted btree extent records

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 12 Oct 2009 20:41:37 -0400
From:	Jeff Mahoney <jeffm@...e.com>
To:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Roman Zippel andr <zippel@...ux-m68k.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH] 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@...ux.vnet.ibm.com>
Signed-off-by: Jeff Mahoney <jeffm@...e.com>
---
 fs/hfs/btree.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/fs/hfs/btree.c
+++ b/fs/hfs/btree.c
@@ -58,6 +58,11 @@ struct hfs_btree *hfs_btree_open(struct
 	}
 	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))
-- 
Jeff Mahoney
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/