From: Jeff Layton <jlayton@redhat.com>
Date: Tue, 5 Apr 2011 23:23:47 +0000 (-0700)
Subject: cifs: check for private_data before trying to put it
X-Git-Tag: v2.6.38.4~68
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7cb41edf395b70a6e48162382c5577967ce92bbf;p=thirdparty%2Fkernel%2Fstable.git

cifs: check for private_data before trying to put it

commit 7797069305d13252fd66cf722aa8f2cbeb3c95cd upstream.

cifs_close doesn't check that the filp->private_data is non-NULL before
trying to put it. That can cause an oops in certain error conditions
that can occur on open or lookup before the private_data is set.

Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-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/file.c b/fs/cifs/file.c
index e964b1cd5dd09..7b2e8ec2709b3 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -575,8 +575,10 @@ reopen_error_exit:
 
 int cifs_close(struct inode *inode, struct file *file)
 {
-	cifsFileInfo_put(file->private_data);
-	file->private_data = NULL;
+	if (file->private_data != NULL) {
+		cifsFileInfo_put(file->private_data);
+		file->private_data = NULL;
+	}
 
 	/* return code from the ->release op is always ignored */
 	return 0;