Re: [PATCH 5.4 00/17] Backport oops_limit to 5.4

[Eric Biggers]

On Thu, Feb 02, 2023 at 12:47:07PM -0500, Sasha Levin wrote:
> On Thu, Feb 02, 2023 at 12:16:52PM -0500, Sasha Levin wrote:
> > On Wed, Feb 01, 2023 at 08:42:38PM -0800, Eric Biggers wrote:
> > > This series backports the patchset
> > > "exit: Put an upper limit on how often we can oops"
> > > (https://lore.kernel.org/linux-mm/20221117233838.give.484-kees@xxxxxxxxxx/T/#u)
> > > to 5.4, as recommended at
> > > https://googleprojectzero.blogspot.com/2023/01/exploiting-null-dereferences-in-linux.html
> > > This follows the backports to 5.10 and 5.15 which already released.
> > > 
> > > This required backporting various prerequisite patches.
> > > 
> > > I've tested that oops_limit and warn_limit work correctly on x86_64.
> > 
> > Queued up all 3 backports, thanks!
> 
> ... and proceeded to drop the 4.19 and 4.14 backports which fail to
> build:
> 
> mm/kasan/report.c: In function 'kasan_end_report':
> mm/kasan/report.c:175:16: error: 'KASAN_BIT_MULTI_SHOT' undeclared (first use in this function)
>   175 |  if (!test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))

Thanks, I'll fix that.  I had grepped for KASAN_BIT_MULTI_SHOT to make sure
those branches had it, but I didn't notice it was defined later in the file :-(

- Eric