svn commit: r332749 - in stable/11/sys: fs/ext2fs ufs/ufs

[Pedro F. Giffuni]

Author: pfg
Date: Thu Apr 19 02:47:21 2018
New Revision: 332749
URL: https://svnweb.freebsd.org/changeset/base/332749

Log:
  MFC r328957:
  {ext2|ufs}_readdir: Avoid setting negative ncookies.
  
  ncookies cannot be negative or the allocator will fail. This should only
  happen if a caller is very broken but we can still try to survive the
  event.
  
  We should probably also verify for uio_resid > MAXPHYS but in that case
  it is not clear that just clipping the ncookies value is an adequate
  response.

Modified:
  stable/11/sys/fs/ext2fs/ext2_lookup.c
  stable/11/sys/ufs/ufs/ufs_vnops.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/fs/ext2fs/ext2_lookup.c
==============================================================================
--- stable/11/sys/fs/ext2fs/ext2_lookup.c	Thu Apr 19 01:15:19 2018	(r332748)
+++ stable/11/sys/fs/ext2fs/ext2_lookup.c	Thu Apr 19 02:47:21 2018	(r332749)
@@ -150,7 +150,10 @@ ext2_readdir(struct vop_readdir_args *ap)
 		return (EINVAL);
 	ip = VTOI(vp);
 	if (ap->a_ncookies != NULL) {
-		ncookies = uio->uio_resid;
+		if (uio->uio_resid < 0)
+			ncookies = 0;
+		else
+			ncookies = uio->uio_resid;
 		if (uio->uio_offset >= ip->i_size)
 			ncookies = 0;
 		else if (ip->i_size - uio->uio_offset < ncookies)

Modified: stable/11/sys/ufs/ufs/ufs_vnops.c
==============================================================================
--- stable/11/sys/ufs/ufs/ufs_vnops.c	Thu Apr 19 01:15:19 2018	(r332748)
+++ stable/11/sys/ufs/ufs/ufs_vnops.c	Thu Apr 19 02:47:21 2018	(r332749)
@@ -2177,7 +2177,10 @@ ufs_readdir(ap)
 	if (ip->i_effnlink == 0)
 		return (0);
 	if (ap->a_ncookies != NULL) {
-		ncookies = uio->uio_resid;
+		if (uio->uio_resid < 0)
+			ncookies = 0;
+		else
+			ncookies = uio->uio_resid;
 		if (uio->uio_offset >= ip->i_size)
 			ncookies = 0;
 		else if (ip->i_size - uio->uio_offset < ncookies)