[05/70] cifs: check for private_data before trying to put it

[Greg KH]

2.6.38-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Jeff Layton <jlayton@xxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Steve French <sfrench@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 fs/cifs/file.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- 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;


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