Fix oops in cifs_strfromUCS_le mounting to servers which do not specify their OS

commit 69765529d701c838df19ea1f5ad2f33a528261ae upstream.

Fixes kernel bug #10451 http://bugzilla.kernel.org/show_bug.cgi?id=10451

Certain NAS appliances do not set the operating system or network operating system
fields in the session setup response on the wire.  cifs was oopsing on the unexpected
zero length response fields (when trying to null terminate a zero length field).

This fixes the oops.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index 06e521a945c33494130c7f1ab637d5ecfbef234c..088e9ae5c58d4dc3865ed7a3b677d8e54ce747fa 100644 (file)
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -1,3 +1,5 @@
+Fix oops in cifs_dfs_ref.c when prefixpath is not reachable when using DFS.
+
 Version 1.54
 ------------
 Fix premature write failure on congested networks (we would give up

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 252fdc0567f1aa186f36f8c68d83f259d6db4ee0..89fac77d1be89a13295dcc3ef89f5e2653d1558a 100644 (file)
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -228,7 +228,7 @@ static int decode_unicode_ssetup(char **pbcc_area, int bleft,
 
        kfree(ses->serverOS);
        /* UTF-8 string will not grow more than four times as big as UCS-16 */
-       ses->serverOS = kzalloc(4 * len, GFP_KERNEL);
+       ses->serverOS = kzalloc((4 * len) + 2 /* trailing null */, GFP_KERNEL);
        if (ses->serverOS != NULL)
                cifs_strfromUCS_le(ses->serverOS, (__le16 *)data, len, nls_cp);
        data += 2 * (len + 1);
@@ -241,7 +241,7 @@ static int decode_unicode_ssetup(char **pbcc_area, int bleft,
                return rc;
 
        kfree(ses->serverNOS);
-       ses->serverNOS = kzalloc(4 * len, GFP_KERNEL); /* BB this is wrong length FIXME BB */
+       ses->serverNOS = kzalloc((4 * len) + 2 /* trailing null */, GFP_KERNEL);
        if (ses->serverNOS != NULL) {
                cifs_strfromUCS_le(ses->serverNOS, (__le16 *)data, len,
                                   nls_cp);