Re: [linux-next:master] [slub] 3a34e8ea62: BUG:KASAN:slab-use-after-free_in_kmem_cache_rcu_uaf

[Jann Horn <jannh@google.com>]

Hi!

On Sun, Aug 25, 2024 at 11:45 AM kernel test robot
<oliver.sang@intel.com> wrote:
> Hello,
>
> kernel test robot noticed "BUG:KASAN:slab-use-after-free_in_kmem_cache_rcu_uaf" on:
>
> commit: 3a34e8ea62cdeba64a66fa4489059c59ba4ec285 ("slub: Introduce CONFIG_SLUB_RCU_DEBUG")
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
>
> [test failed on linux-next/master c79c85875f1af04040fe4492ed94ce37ad729c4d]
>
> in testcase: kunit
> version:
> with following parameters:
>
>         group: group-00
>
>
>
> compiler: gcc-12
> test machine: 36 threads 1 sockets Intel(R) Core(TM) i9-10980XE CPU @ 3.00GHz (Cascade Lake) with 128G memory
>
> (please refer to attached dmesg/kmsg for entire log/backtrace)
>
>
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <oliver.sang@intel.com>
> | Closes: https://lore.kernel.org/oe-lkp/202408251741.4ce3b34e-oliver.sang@intel.com
>
>
> The kernel config and materials to reproduce are available at:
> https://download.01.org/0day-ci/archive/20240825/202408251741.4ce3b34e-oliver.sang@intel.com

Oh, this is a weird one...

Do you happen to have either the vmlinux ELF file that this issue
happened with, or a version of the bug report that's been run through
scripts/decode_stacktrace.sh, so that we can tell whether the reported
slab-use-after-free is on line 1029 (which would mean that either ASAN
is not tracking the state of the object correctly or the object is
freed earlier than it should) or line 1039 (which would mean the
KUNIT_EXPECT_KASAN_FAIL() is not working at it should)?