4.9-stable patches

added patches:
	nfsd4-readdirplus-shouldn-t-return-parent-of-export.patch

diff --git a/queue-4.9/nfsd4-readdirplus-shouldn-t-return-parent-of-export.patch b/queue-4.9/nfsd4-readdirplus-shouldn-t-return-parent-of-export.patch
new file mode 100644 (file)
index 0000000..1bf745f
--- /dev/null
+++ b/queue-4.9/nfsd4-readdirplus-shouldn-t-return-parent-of-export.patch
@@ -0,0 +1,52 @@
+From 51b2ee7d006a736a9126e8111d1f24e4fd0afaa6 Mon Sep 17 00:00:00 2001
+From: "J. Bruce Fields" <bfields@redhat.com>
+Date: Mon, 11 Jan 2021 16:01:29 -0500
+Subject: nfsd4: readdirplus shouldn't return parent of export
+
+From: J. Bruce Fields <bfields@redhat.com>
+
+commit 51b2ee7d006a736a9126e8111d1f24e4fd0afaa6 upstream.
+
+If you export a subdirectory of a filesystem, a READDIRPLUS on the root
+of that export will return the filehandle of the parent with the ".."
+entry.
+
+The filehandle is optional, so let's just not return the filehandle for
+".." if we're at the root of an export.
+
+Note that once the client learns one filehandle outside of the export,
+they can trivially access the rest of the export using further lookups.
+
+However, it is also not very difficult to guess filehandles outside of
+the export.  So exporting a subdirectory of a filesystem should
+considered equivalent to providing access to the entire filesystem.  To
+avoid confusion, we recommend only exporting entire filesystems.
+
+Reported-by: Youjipeng <wangzhibei1999@gmail.com>
+Signed-off-by: J. Bruce Fields <bfields@redhat.com>
+Cc: stable@vger.kernel.org
+Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/nfsd/nfs3xdr.c |    7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+--- a/fs/nfsd/nfs3xdr.c
++++ b/fs/nfsd/nfs3xdr.c
+@@ -822,9 +822,14 @@ compose_entry_fh(struct nfsd3_readdirres
+       if (isdotent(name, namlen)) {
+               if (namlen == 2) {
+                       dchild = dget_parent(dparent);
+-                      /* filesystem root - cannot return filehandle for ".." */
++                      /*
++                       * Don't return filehandle for ".." if we're at
++                       * the filesystem or export root:
++                       */
+                       if (dchild == dparent)
+                               goto out;
++                      if (dparent == exp->ex_path.dentry)
++                              goto out;
+               } else
+                       dchild = dget(dparent);
+       } else

diff --git a/queue-4.9/series b/queue-4.9/series
index f215617632c68419731755b79f4f82c38075fdd7..10cb85d5d361dedd6de8d1852f5131e47c40ce9f 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -22,3 +22,4 @@ net-sunrpc-interpret-the-return-value-of-kstrtou32-correctly.patch
 netfilter-conntrack-fix-reading-nf_conntrack_buckets.patch
 usb-ohci-make-distrust_firmware-param-default-to-false.patch
 compiler.h-raise-minimum-version-of-gcc-to-5.1-for-arm64.patch
+nfsd4-readdirplus-shouldn-t-return-parent-of-export.patch