Re: [PATCH v3 1/3] lib/test_kasan: Add bitops tests

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Thanks, I've sent v4.

On Thu, 13 Jun 2019 at 12:49, Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> wrote:
>
>
>
> On 5/31/19 6:08 PM, Marco Elver wrote:
> > This adds bitops tests to the test_kasan module. In a follow-up patch,
> > support for bitops instrumentation will be added.
> >
> > Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
> > ---
> > Changes in v3:
> > * Use kzalloc instead of kmalloc.
> > * Use sizeof(*bits).
> >
> > Changes in v2:
> > * Use BITS_PER_LONG.
> > * Use heap allocated memory for test, as newer compilers (correctly)
> >   warn on OOB stack access.
> > ---
> >  lib/test_kasan.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 72 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> > index 7de2702621dc..1ef9702327d2 100644
> > --- a/lib/test_kasan.c
> > +++ b/lib/test_kasan.c
> > @@ -11,16 +11,17 @@
> >
> >  #define pr_fmt(fmt) "kasan test: %s " fmt, __func__
> >
> > +#include <linux/bitops.h>
> >  #include <linux/delay.h>
> > +#include <linux/kasan.h>
> >  #include <linux/kernel.h>
> > -#include <linux/mman.h>
> >  #include <linux/mm.h>
> > +#include <linux/mman.h>
> > +#include <linux/module.h>
> >  #include <linux/printk.h>
> >  #include <linux/slab.h>
> >  #include <linux/string.h>
> >  #include <linux/uaccess.h>
> > -#include <linux/module.h>
> > -#include <linux/kasan.h>
> >
> >  /*
> >   * Note: test functions are marked noinline so that their names appear in
> > @@ -623,6 +624,73 @@ static noinline void __init kasan_strings(void)
> >       strnlen(ptr, 1);
> >  }
> >
> > +static noinline void __init kasan_bitops(void)
> > +{
> > +     long *bits = kzalloc(sizeof(*bits), GFP_KERNEL);
>
> It would be safer to do kzalloc(sizeof(*bits) + 1, GFP_KERNEL) and change tests accordingly to: set_bit(BITS_PER_LONG + 1, bits) ...
> kmalloc will internally round up allocation to 16-bytes, so we won't be actually corrupting someone elses memory.
>
>
> > +     if (!bits)
> > +             return;
> > +
> > +     pr_info("within-bounds in set_bit");
> > +     set_bit(0, bits);
> > +
> > +     pr_info("within-bounds in set_bit");
> > +     set_bit(BITS_PER_LONG - 1, bits);
>
>
> I'd remove these two. There are plenty of within bounds set_bit() in the kernel so they are well tested already.
>
> --
> You received this message because you are subscribed to the Google Groups "kasan-dev" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@xxxxxxxxxxxxxxxx.
> To post to this group, send email to kasan-dev@xxxxxxxxxxxxxxxx.
> To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/5c35bc08-749f-dbc4-09d0-fcf14b1da1b3%40virtuozzo.com.
> For more options, visit https://groups.google.com/d/optout.



[Index of Archives]     [Linux Kernel]     [Kernel Newbies]     [x86 Platform Driver]     [Netdev]     [Linux Wireless]     [Netfilter]     [Bugtraq]     [Linux Filesystems]     [Yosemite Discussion]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]

  Powered by Linux