Re: [PATCH] USB: serial/ftdi_sio.c Fix kernel oops

[Ben Hutchings]

On Fri, 2013-06-07 at 15:14 +0200, Lotfi Manseur wrote:
> Handle null termios in ftdi_set_termios(), introduced in
> commit 552f6bf1bb0eda0011c0525dd587aa9e7ba5b846
> This has been corrected in the mainline by
> commits c515598e0f5769916c31c00392cc2bfe6af74e55 and
> a816e3113b63753c330ca4751ea1d208e93e3015.
> 
> This is to be fixed in longterm 2.6.32.60 and 3.4.47.
> This bug has been found with coccinelle.
> 
> Signed-off-by: Lotfi Manseur <lotfi.manseur@xxxxxxx>
> Signed-off-by: Nicolas Palix <nicolas.palix@xxxxxxx>

I've queued up those changes for 3.2.  This backported version seems
nicer, but we generally prefer to use patches that are as close as
possible to those in mainline.

Ben.

> ---
>  drivers/usb/serial/ftdi_sio.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
> index c374beb..615bd9e 100644
> --- a/drivers/usb/serial/ftdi_sio.c
> +++ b/drivers/usb/serial/ftdi_sio.c
> @@ -2364,7 +2364,8 @@ static void ftdi_set_termios(struct tty_struct *tty,
>  
>  	cflag = termios->c_cflag;
>  
> -	if (old_termios->c_cflag == termios->c_cflag
> +	if (old_termios
> +	    && old_termios->c_cflag == termios->c_cflag
>  	    && old_termios->c_ispeed == termios->c_ispeed
>  	    && old_termios->c_ospeed == termios->c_ospeed)
>  		goto no_c_cflag_changes;
> @@ -2373,7 +2374,8 @@ static void ftdi_set_termios(struct tty_struct *tty,
>  	   ftdi_sio_read_bulk_callback  - need to examine what this means -
>  	   don't see any problems yet */
>  
> -	if ((old_termios->c_cflag & (CSIZE|PARODD|PARENB|CMSPAR|CSTOPB)) ==
> +	if (old_termios &&
> +	    (old_termios->c_cflag & (CSIZE|PARODD|PARENB|CMSPAR|CSTOPB)) ==
>  	    (termios->c_cflag & (CSIZE|PARODD|PARENB|CMSPAR|CSTOPB)))
>  		goto no_data_parity_stop_changes;
>  

-- 
Ben Hutchings
friends: People who know you well, but like you anyway.

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