Messages in this thread | | | Date | Fri, 10 Jun 2022 15:28:04 +0200 | From | Greg KH <> | Subject | Re: [PATCH 1/2] char: lp: ensure that index has not exceeded LP_NO |
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On Fri, Jun 03, 2022 at 06:30:39PM +0530, Shreenidhi Shedi wrote: > From: Shreenidhi Shedi <sshedi@vmware.com> > > After finishing the loop, index value can be equal to LP_NO and lp_table > array is of size LP_NO, so this can end up in accessing an out of bound > address in lp_register function. > > Signed-off-by: Shreenidhi Shedi <sshedi@vmware.com> > --- > drivers/char/lp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/char/lp.c b/drivers/char/lp.c > index 0e22e3b0a..d474d02b6 100644 > --- a/drivers/char/lp.c > +++ b/drivers/char/lp.c > @@ -972,7 +972,7 @@ static void lp_attach(struct parport *port) > if (port_num[i] == -1) > break; > > - if (!lp_register(i, port)) > + if (i < LP_NO && !lp_register(i, port)) > lp_count++;
How can this ever be needed? Look at the check further up for the check of lp_count which prevents this from every going too large.
So how can an address be accessed out of bound here?
thanks,
greg k-h
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