[kernel] r9597 - in dists/etch-security/linux-2.6/debian: . patches/bugfix patches/series

Tue Oct 2 16:19:10 UTC 2007

Author: dannf
Date: Tue Oct  2 16:19:10 2007
New Revision: 9597

Log:
* bugfix/hugetlb-prio_tree-unit-fix.patch
  [SECURITY] Fix misconversion of hugetlb_vmtruncate_list to prio_tree
  which could be used to trigger a BUG_ON() call in exit_mmap.
  See CVE-2007-4133

Added:
   dists/etch-security/linux-2.6/debian/patches/bugfix/hugetlb-prio_tree-unit-fix.patch
   dists/etch-security/linux-2.6/debian/patches/series/13etch4
Modified:
   dists/etch-security/linux-2.6/debian/changelog

Modified: dists/etch-security/linux-2.6/debian/changelog
==============================================================================

--- dists/etch-security/linux-2.6/debian/changelog	(original)
+++ dists/etch-security/linux-2.6/debian/changelog	Tue Oct  2 16:19:10 2007
@@ -1,5 +1,6 @@
-linux-2.6 (2.6.18.dfsg.1-13etch4) UNRELEASED; urgency=low
+linux-2.6 (2.6.18.dfsg.1-13etch4) UNRELEASED-stable-security; urgency=high
 
+  [ Bastian Blank ]
   * bugfix/amd64-zero-extend-32bit-ptrace-xen.patch
     [SECURITY] Zero extend all registers after ptrace in 32-bit entry path
     (Xen).
@@ -8,7 +9,13 @@
     [SECURITY] Don't leak NT bit into next task (Xen).
     See CVE-2006-5755
 
- -- Bastian Blank <waldi at debian.org>  Tue, 02 Oct 2007 11:09:12 +0200
+  [ dann frazier ]
+  * bugfix/hugetlb-prio_tree-unit-fix.patch
+    [SECURITY] Fix misconversion of hugetlb_vmtruncate_list to prio_tree
+    which could be used to trigger a BUG_ON() call in exit_mmap.
+    See CVE-2007-4133
+
+ -- dann frazier <dannf at debian.org>  Tue, 02 Oct 2007 10:01:43 -0600
 
 linux-2.6 (2.6.18.dfsg.1-13etch3) stable-security; urgency=high
 

Added: dists/etch-security/linux-2.6/debian/patches/bugfix/hugetlb-prio_tree-unit-fix.patch
==============================================================================
--- (empty file)
+++ dists/etch-security/linux-2.6/debian/patches/bugfix/hugetlb-prio_tree-unit-fix.patch	Tue Oct  2 16:19:10 2007
@@ -0,0 +1,85 @@
+From: Hugh Dickins <hugh at veritas.com>
+Date: Sat, 28 Oct 2006 17:38:43 +0000 (-0700)
+Subject: [PATCH] hugetlb: fix prio_tree unit
+X-Git-Tag: v2.6.19-rc4~50
+X-Git-Url: http://git.kernel.org/gitweb.cgi?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=856fc29505556cf263f3dcda2533cf3766c14ab6
+
+[PATCH] hugetlb: fix prio_tree unit
+
+hugetlb_vmtruncate_list was misconverted to prio_tree: its prio_tree is in
+units of PAGE_SIZE (PAGE_CACHE_SIZE) like any other, not HPAGE_SIZE (whereas
+its radix_tree is kept in units of HPAGE_SIZE, otherwise slots would be
+absurdly sparse).
+
+At first I thought the error benign, just calling __unmap_hugepage_range on
+more vmas than necessary; but on 32-bit machines, when the prio_tree is
+searched correctly, it happens to ensure the v_offset calculation won't
+overflow.  As it stood, when truncating at or beyond 4GB, it was liable to
+discard pages COWed from lower offsets; or even to clear pmd entries of
+preceding vmas, triggering exit_mmap's BUG_ON(nr_ptes).
+
+Signed-off-by: Hugh Dickins <hugh at veritas.com>
+Cc: Adam Litke <agl at us.ibm.com>
+Cc: David Gibson <david at gibson.dropbear.id.au>
+Cc: "Chen, Kenneth W" <kenneth.w.chen at intel.com>
+Signed-off-by: Andrew Morton <akpm at osdl.org>
+Signed-off-by: Linus Torvalds <torvalds at osdl.org>
+---
+
+diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
+index 0b23b96..0bea6a6 100644
+--- a/fs/hugetlbfs/inode.c
++++ b/fs/hugetlbfs/inode.c
+@@ -271,26 +271,24 @@ static void hugetlbfs_drop_inode(struct inode *inode)
+ 		hugetlbfs_forget_inode(inode);
+ }
+ 
+-/*
+- * h_pgoff is in HPAGE_SIZE units.
+- * vma->vm_pgoff is in PAGE_SIZE units.
+- */
+ static inline void
+-hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff)
++hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)
+ {
+ 	struct vm_area_struct *vma;
+ 	struct prio_tree_iter iter;
+ 
+-	vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) {
+-		unsigned long h_vm_pgoff;
++	vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {
+ 		unsigned long v_offset;
+ 
+-		h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT);
+-		v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT;
+ 		/*
+-		 * Is this VMA fully outside the truncation point?
++		 * Can the expression below overflow on 32-bit arches?
++		 * No, because the prio_tree returns us only those vmas
++		 * which overlap the truncated area starting at pgoff,
++		 * and no vma on a 32-bit arch can span beyond the 4GB.
+ 		 */
+-		if (h_vm_pgoff >= h_pgoff)
++		if (vma->vm_pgoff < pgoff)
++			v_offset = (pgoff - vma->vm_pgoff) << PAGE_SHIFT;
++		else
+ 			v_offset = 0;
+ 
+ 		__unmap_hugepage_range(vma,
+@@ -303,14 +301,14 @@ hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff)
+  */
+ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
+ {
+-	unsigned long pgoff;
++	pgoff_t pgoff;
+ 	struct address_space *mapping = inode->i_mapping;
+ 
+ 	if (offset > inode->i_size)
+ 		return -EINVAL;
+ 
+ 	BUG_ON(offset & ~HPAGE_MASK);
+-	pgoff = offset >> HPAGE_SHIFT;
++	pgoff = offset >> PAGE_SHIFT;
+ 
+ 	inode->i_size = offset;
+ 	spin_lock(&mapping->i_mmap_lock);

Added: dists/etch-security/linux-2.6/debian/patches/series/13etch4
==============================================================================
--- (empty file)
+++ dists/etch-security/linux-2.6/debian/patches/series/13etch4	Tue Oct  2 16:19:10 2007
@@ -0,0 +1 @@
++ bugfix/hugetlb-prio_tree-unit-fix.patch

