Re: [PATCH] staging: gpib: avoid buffer overflow

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Oct 17, 2024 at 08:23:25PM +0200, Greg KH wrote:
> On Tue, Oct 15, 2024 at 08:38:13PM +0200, Kees Bakker wrote:
> > The remaining buffer size for snprintf also depends on `pos`.
> > 
> > Signed-off-by: Kees Bakker <kees@ijzerbout.nl>
> > ---
> >  drivers/staging/gpib/ni_usb/ni_usb_gpib.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
> > index 1da263676f2a..4df1ceaa138f 100644
> > --- a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
> > +++ b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
> > @@ -364,7 +364,7 @@ static void ni_usb_dump_raw_block(const u8 *raw_data, int length)
> >  			pr_info("%s\n", print_buf);
> >  			pos = 0;
> >  		}
> > -		pos += snprintf(&print_buf[pos], RAW_BUF_SIZE, " %02x", raw_data[i]);
> > +		pos += snprintf(&print_buf[pos], RAW_BUF_SIZE - pos, " %02x", raw_data[i]);
> >  	}
> >  	if (pos)
> >  		pr_info("%s\n", print_buf);
> 
> The better thing to do would be to delete this whole function and just
> use the in-kernel hex_dump_to_buffer() function instead, which handles
> all of this logic properly.
> 
> Can you do that instead?

Oops, I mean print_hex_dump().

thanks,

greg k-h