Re: [PATCH] potential NULL deref in serial/core.c

From: Ben Collins (bcollins@debian.org)
Date: Wed Oct 23 2002 - 14:10:57 EST

On Wed, Oct 23, 2002 at 03:02:11PM -0400, Ben Collins wrote:
> Not sure if it's supposed to be a BUG() for tty to be NULL, but it's
> surely a bug to dereference it before checking for that.
>

Ug. Find one more after I sent this email.

--- drivers/serial/core.c~ 2002-10-23 14:59:17.000000000 -0400
+++ drivers/serial/core.c 2002-10-23 15:07:55.000000000 -0400
@@ -472,10 +472,12 @@
 
 static void uart_put_char(struct tty_struct *tty, unsigned char ch)
 {
- struct uart_info *info = tty->driver_data;
+ struct uart_info *info;
 
- if (tty)
+ if (tty) {
+ info = tty->driver_data;
                 __uart_put_char(info->port, &info->xmit, ch);
+ }
 }
 
 static void uart_flush_chars(struct tty_struct *tty)
@@ -487,10 +489,15 @@
 uart_write(struct tty_struct *tty, int from_user, const unsigned char * buf,
            int count)
 {
- struct uart_info *info = tty->driver_data;
+ struct uart_info *info;
         int ret;
 
- if (!tty || !info->xmit.buf)
+ if (!tty)
+ return 0;
+
+ info = tty->driver_data;
+
+ if (!info->xmit.buf)
                 return 0;
 
         if (from_user) 

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This archive was generated by hypermail 2b29 : Wed Oct 23 2002 - 22:01:05 EST