Re: [PATCH] proc: Fix uninitialized byte read in get_mm_cmdline()

From: Alexey Dobriyan
Date: Fri Jul 12 2019 - 13:46:38 EST


On Fri, Jul 12, 2019 at 06:36:26PM +0200, Oleg Nesterov wrote:
> On 07/12, Alexey Izbyshev wrote:
> >
> > --- a/fs/proc/base.c
> > +++ b/fs/proc/base.c
> > @@ -275,6 +275,8 @@ static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
> > if (got <= offset)
> > break;
> > got -= offset;
> > + if (got < size)
> > + size = got;
>
> Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>

The proper fix to all /proc/*/cmdline problems is to revert

f5b65348fd77839b50e79bc0a5e536832ea52d8d
proc: fix missing final NUL in get_mm_cmdline() rewrite

5ab8271899658042fabc5ae7e6a99066a210bc0e
fs/proc: simplify and clarify get_mm_cmdline() function