[kernel] r18258 - in dists/trunk/linux-2.6/debian: . patches/bugfix/all patches/series

[Ben Hutchings]

Author: benh
Date: Sun Nov 13 16:51:57 2011
New Revision: 18258

Log:
hfs: fix hfs_find_init() sb->ext_tree NULL ptr oops (CVE-2011-2203)

Added:
   dists/trunk/linux-2.6/debian/patches/bugfix/all/hfs-fix-hfs_find_init-sb-ext_tree-NULL-ptr-oops.patch
Modified:
   dists/trunk/linux-2.6/debian/changelog
   dists/trunk/linux-2.6/debian/patches/series/base

Modified: dists/trunk/linux-2.6/debian/changelog
==============================================================================
--- dists/trunk/linux-2.6/debian/changelog	Sun Nov 13 16:36:30 2011	(r18257)
+++ dists/trunk/linux-2.6/debian/changelog	Sun Nov 13 16:51:57 2011	(r18258)
@@ -18,6 +18,7 @@
   * [alpha] Remove old, broken udeb configuration
   * DFSG: Remove drivers/staging/ft1000/ft1000-*/*.img, non-free
     firmware for drivers we don't build
+  * hfs: fix hfs_find_init() sb->ext_tree NULL ptr oops (CVE-2011-2203)
 
  -- Ben Hutchings <ben at decadent.org.uk>  Fri, 04 Nov 2011 15:05:47 +0000
 

Added: dists/trunk/linux-2.6/debian/patches/bugfix/all/hfs-fix-hfs_find_init-sb-ext_tree-NULL-ptr-oops.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ dists/trunk/linux-2.6/debian/patches/bugfix/all/hfs-fix-hfs_find_init-sb-ext_tree-NULL-ptr-oops.patch	Sun Nov 13 16:51:57 2011	(r18258)
@@ -0,0 +1,89 @@
+From: Phillip Lougher <plougher at redhat.com>
+Date: Wed, 2 Nov 2011 13:38:01 -0700
+Subject: [PATCH] hfs: fix hfs_find_init() sb->ext_tree NULL ptr oops
+
+commit 434a964daa14b9db083ce20404a4a2add54d037a upstream.
+
+Clement Lecigne reports a filesystem which causes a kernel oops in
+hfs_find_init() trying to dereference sb->ext_tree which is NULL.
+
+This proves to be because the filesystem has a corrupted MDB extent
+record, where the extents file does not fit into the first three extents
+in the file record (the first blocks).
+
+In hfs_get_block() when looking up the blocks for the extent file
+(HFS_EXT_CNID), it fails the first blocks special case, and falls
+through to the extent code (which ultimately calls hfs_find_init())
+which is in the process of being initialised.
+
+Hfs avoids this scenario by always having the extents b-tree fitting
+into the first blocks (the extents B-tree can't have overflow extents).
+
+The fix is to check at mount time that the B-tree fits into first
+blocks, i.e.  fail if HFS_I(inode)->alloc_blocks >=
+HFS_I(inode)->first_blocks
+
+Note, the existing commit 47f365eb57573 ("hfs: fix oops on mount with
+corrupted btree extent records") becomes subsumed into this as a special
+case, but only for the extents B-tree (HFS_EXT_CNID), it is perfectly
+acceptable for the catalog B-Tree file to grow beyond three extents,
+with the remaining extent descriptors in the extents overfow.
+
+This fixes CVE-2011-2203
+
+Reported-by: Clement LECIGNE <clement.lecigne at netasq.com>
+Signed-off-by: Phillip Lougher <plougher at redhat.com>
+Cc: Jeff Mahoney <jeffm at suse.com>
+Cc: Christoph Hellwig <hch at lst.de>
+Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
+---
+ fs/hfs/btree.c |   20 +++++++++++++++-----
+ 1 files changed, 15 insertions(+), 5 deletions(-)
+
+diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c
+index 3ebc437..1cbdeea 100644
+--- a/fs/hfs/btree.c
++++ b/fs/hfs/btree.c
+@@ -46,11 +46,26 @@ struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp ke
+ 	case HFS_EXT_CNID:
+ 		hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
+ 				    mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
++		if (HFS_I(tree->inode)->alloc_blocks >
++					HFS_I(tree->inode)->first_blocks) {
++			printk(KERN_ERR "hfs: invalid btree extent records\n");
++			unlock_new_inode(tree->inode);
++			goto free_inode;
++		}
++
+ 		tree->inode->i_mapping->a_ops = &hfs_btree_aops;
+ 		break;
+ 	case HFS_CAT_CNID:
+ 		hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
+ 				    mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
++
++		if (!HFS_I(tree->inode)->first_blocks) {
++			printk(KERN_ERR "hfs: invalid btree extent records "
++								"(0 size).\n");
++			unlock_new_inode(tree->inode);
++			goto free_inode;
++		}
++
+ 		tree->inode->i_mapping->a_ops = &hfs_btree_aops;
+ 		break;
+ 	default:
+@@ -59,11 +74,6 @@ 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))
+-- 
+1.7.7.2
+

Modified: dists/trunk/linux-2.6/debian/patches/series/base
==============================================================================
--- dists/trunk/linux-2.6/debian/patches/series/base	Sun Nov 13 16:36:30 2011	(r18257)
+++ dists/trunk/linux-2.6/debian/patches/series/base	Sun Nov 13 16:51:57 2011	(r18258)
@@ -55,3 +55,4 @@
 + bugfix/all/CIFS-Fixup-trivial-checkpatch-warning.patch
 + bugfix/all/Fix-build-break-when-freezer-not-configured.patch
 + bugfix/all/PM-Freezer-Reimplement-wait_event_freezekillable-usi.patch
++ bugfix/all/hfs-fix-hfs_find_init-sb-ext_tree-NULL-ptr-oops.patch