lkml.org 
[lkml]   [2022]   [Mar]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v6 31/39] kasan, vmalloc: only tag normal vmalloc allocations
On Tue, Mar 8, 2022 at 4:17 PM Vasily Gorbik <gor@linux.ibm.com> wrote:
>
> On Mon, Jan 24, 2022 at 07:05:05PM +0100, andrey.konovalov@linux.dev wrote:
> > From: Andrey Konovalov <andreyknvl@google.com>
> >
> > The kernel can use to allocate executable memory. The only supported way
> > to do that is via __vmalloc_node_range() with the executable bit set in
> > the prot argument. (vmap() resets the bit via pgprot_nx()).
> >
> > Once tag-based KASAN modes start tagging vmalloc allocations, executing
> > code from such allocations will lead to the PC register getting a tag,
> > which is not tolerated by the kernel.
> >
> > Only tag the allocations for normal kernel pages.
> >
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
>
> This breaks s390 and produce huge amount of false positives.
> I haven't been testing linux-next with KASAN for while, now tried it with
> next-20220308 and bisected false positives to this commit.
>
> Any idea what is going wrong here?

Hi Vasily,

Could you try the attached fix?

Thanks!
[unhandled content-type:application/octet-stream]
\
 
 \ /
  Last update: 2022-03-08 16:32    [W:0.078 / U:0.988 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site