tty: wipe buffer.

After we are done with the tty buffer, zero it out.

Reported-by: aszlig <aszlig@nix.build>
Tested-by: Milan Broz <gmazyland@gmail.com>
Tested-by: Daniel Zatovic <daniel.zatovic@gmail.com>
Tested-by: aszlig <aszlig@nix.build>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 76151c002858..77070c2d1240 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -473,11 +473,15 @@ receive_buf(struct tty_port *port, struct tty_buffer *head, int count)
 {
         unsigned char *p = char_buf_ptr(head, head->read);
         char          *f = NULL;
+        int n;
 
         if (~head->flags & TTYB_NORMAL)
                 f = flag_buf_ptr(head, head->read);
 
-        return port->client_ops->receive_buf(port, p, f, count);
+        n = port->client_ops->receive_buf(port, p, f, count);
+        if (n > 0)
+                memset(p, 0, n);
+        return n;
 }
 
 /**