svn commit: r275834 - stable/10/sys/fs/ext2fs

[Pedro F. Giffuni]

Author: pfg
Date: Tue Dec 16 18:45:31 2014
New Revision: 275834
URL: https://svnweb.freebsd.org/changeset/base/275834

Log:
  MFC	r275645;
  
  ext2fs: Fix old out-of-bounds access.
  
  Overrunning buffer pointed to by (caddr_t)&oip->i_db[0] of 48 bytes by
  passing it to a function which accesses it at byte offset 59 using
  argument 60UL.
  
  The issue was inherited from an older FFS implementation and
  fixed there with by merging UFS2 in r98542. We follow the
  FFS fix.
  
  CID:		1007665
  Discussed with:	bde

Modified:
  stable/10/sys/fs/ext2fs/ext2_inode.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/fs/ext2fs/ext2_inode.c
==============================================================================
--- stable/10/sys/fs/ext2fs/ext2_inode.c	Tue Dec 16 18:28:33 2014	(r275833)
+++ stable/10/sys/fs/ext2fs/ext2_inode.c	Tue Dec 16 18:45:31 2014	(r275834)
@@ -224,14 +224,18 @@ ext2_truncate(struct vnode *vp, off_t le
 	 * will be returned to the free list.  lastiblock values are also
 	 * normalized to -1 for calls to ext2_indirtrunc below.
 	 */
-	bcopy((caddr_t)&oip->i_db[0], (caddr_t)oldblks, sizeof(oldblks));
-	for (level = TRIPLE; level >= SINGLE; level--)
+	for (level = TRIPLE; level >= SINGLE; level--) {
+		oldblks[NDADDR + level] = oip->i_ib[level];
 		if (lastiblock[level] < 0) {
 			oip->i_ib[level] = 0;
 			lastiblock[level] = -1;
 		}
-	for (i = NDADDR - 1; i > lastblock; i--)
-		oip->i_db[i] = 0;
+	}
+	for (i = 0; i < NDADDR; i++) {
+		oldblks[i] = oip->i_db[i];
+		if (i > lastblock)
+			oip->i_db[i] = 0;
+	}
 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
 	allerror = ext2_update(ovp, !DOINGASYNC(ovp));
 
@@ -241,8 +245,14 @@ ext2_truncate(struct vnode *vp, off_t le
 	 * Note that we save the new block configuration so we can check it
 	 * when we are done.
 	 */
-	bcopy((caddr_t)&oip->i_db[0], (caddr_t)newblks, sizeof(newblks));
-	bcopy((caddr_t)oldblks, (caddr_t)&oip->i_db[0], sizeof(oldblks));
+	for (i = 0; i < NDADDR; i++) {
+		newblks[i] = oip->i_db[i];
+		oip->i_db[i] = oldblks[i];
+	}
+	for (i = 0; i < NIADDR; i++) {
+		newblks[NDADDR + i] = oip->i_ib[i];
+		oip->i_ib[i] = oldblks[NDADDR + i];
+	}
 	oip->i_size = osize;
 	error = vtruncbuf(ovp, cred, length, (int)fs->e2fs_bsize);
 	if (error && (allerror == 0))