svn commit: r231545 - stable/9/sys/fs/nfsclient

[Rick Macklem]

Author: rmacklem
Date: Sun Feb 12 06:01:49 2012
New Revision: 231545
URL: http://svn.freebsd.org/changeset/base/231545

Log:
  MFC: r231133
  r228827 fixed a problem where copying of NFSv4 open credentials into
  a credential structure would corrupt it. This happened when the
  p argument was != NULL. However, I now realize that the copying of
  open credentials should only happen for p == NULL, since that indicates
  that it is a read-ahead or write-behind. This patch fixes this.
  After this commit, r228827 could be reverted, but I think the code is
  clearer and safer with the patch, so I am going to leave it in.
  Without this patch, it was possible that a NFSv4 VOP_SETATTR() could have
  changed the credentials of the caller. This would have happened if
  the process doing the VOP_SETATTR() did not have the file open, but
  some other process running as a different uid had the file open for writing
  at the same time.

Modified:
  stable/9/sys/fs/nfsclient/nfs_clstate.c
Directory Properties:
  stable/9/sys/   (props changed)
  stable/9/sys/amd64/include/xen/   (props changed)
  stable/9/sys/boot/   (props changed)
  stable/9/sys/boot/i386/efi/   (props changed)
  stable/9/sys/boot/ia64/efi/   (props changed)
  stable/9/sys/boot/ia64/ski/   (props changed)
  stable/9/sys/boot/powerpc/boot1.chrp/   (props changed)
  stable/9/sys/boot/powerpc/ofw/   (props changed)
  stable/9/sys/cddl/contrib/opensolaris/   (props changed)
  stable/9/sys/conf/   (props changed)
  stable/9/sys/contrib/dev/acpica/   (props changed)
  stable/9/sys/contrib/octeon-sdk/   (props changed)
  stable/9/sys/contrib/pf/   (props changed)
  stable/9/sys/contrib/x86emu/   (props changed)

Modified: stable/9/sys/fs/nfsclient/nfs_clstate.c
==============================================================================
--- stable/9/sys/fs/nfsclient/nfs_clstate.c	Sun Feb 12 05:34:01 2012	(r231544)
+++ stable/9/sys/fs/nfsclient/nfs_clstate.c	Sun Feb 12 06:01:49 2012	(r231545)
@@ -559,8 +559,12 @@ nfscl_getstateid(vnode_t vp, u_int8_t *n
 			NFSUNLOCKCLSTATE();
 			return (ENOENT);
 		}
-		/* for read aheads or write behinds, use the open cred */
-		newnfs_copycred(&op->nfso_cred, cred);
+		/*
+		 * For read aheads or write behinds, use the open cred.
+		 * A read ahead or write behind is indicated by p == NULL.
+		 */
+		if (p == NULL)
+			newnfs_copycred(&op->nfso_cred, cred);
 	}
 
 	/*