Re: Linux6.14-rc5 BUG: spinlock bad magic in z3fold_zpool_free

[Matthew Wilcox <willy@infradead.org>]

On Wed, Mar 26, 2025 at 03:43:28PM -0400, Nhat Pham wrote:
> On Wed, Mar 26, 2025 at 10:32 AM Nhat Pham <nphamcs@gmail.com> wrote:
> > On Wed, Mar 26, 2025 at 10:11 AM ffhgfv <xnxc22xnxc22@qq.com> wrote:
> > >
> > > Hello, I found a bug titled " BUG: spinlock bad magic in z3fold_zpool_free   " with modified syzkaller in the Linux6.14-rc5.
> > > If you fix this issue, please add the following tag to the commit:  Reported-by: Jianzhou Zhao <xnxc22xnxc22@qq.com>,    xingwei lee <xrivendell7@gmail.com>, Zhizhuo Tang <strforexctzzchange@foxmail.com>
> >
> > Please stop using z3fold :) We already removed it upstream.
> 
> To clarify a little bit - we've found that z3fold is buggy (for a very
> long time), and does not outperform zsmalloc in many of the workloads
> we test on (both microbenchmark and real production workloads). We've
> deprecated it since 6.12:
> 
> https://github.com/torvalds/linux/commit/7a2369b74abf76cd3e54c45b30f6addb497f831b
> 
> and will remove it altogether:
> 
> https://lore.kernel.org/all/20250129180633.3501650-1-yosry.ahmed@linux.dev/
> 
> Perhaps Vitaly can fix the issue for stability's sake (or in case
> there is a reason why you MUST use z3fold)? But I strongly recommend
> you experiment with zsmalloc :)

This group are syzkaller kiddies.  They have no understanding of what
they're testing; they're just running their fuzzer and sending emails.
They don't care what's useful, so there's a lot of noise from unmaintained
filesystems and so on.