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From: Nhat Pham <nphamcs@gmail.com>
Date: Tue, 26 Dec 2023 16:23:53 -0800
Message-ID: <CAKEwX=NHdr9=hUBiZhnLZyRPsp=JwN3Vkwud2XEn3=pNurYGpQ@mail.gmail.com>
Subject: Re: [syzbot] [crypto?] general protection fault in
 scatterwalk_copychunks (5)
To: Chris Li <chrisl@kernel.org>
Cc: syzbot <syzbot+3eff5e51bf1db122a16e@syzkaller.appspotmail.com>, 
	akpm@linux-foundation.org, davem@davemloft.net, herbert@gondor.apana.org.au, 
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, 
	syzkaller-bugs@googlegroups.com, yosryahmed@google.com, 
	zhouchengming@bytedance.com
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On Tue, Dec 26, 2023 at 3:30=E2=80=AFPM Chris Li <chrisl@kernel.org> wrote:
>
> Again, sorry I was looking at the decompression side rather than the
> compression side. The compression side does not even offer a safe
> version of the compression function.
> That seems to be dangerous. It seems for now we should make the zswap
> roll back to 2 page buffer until we have a safe way to do compression
> without overwriting the output buffers.

Unfortunately, I think this is the way - at least until we rework the
crypto/compression API (if that's even possible?).
I still think the 2 page buffer is dumb, but it is what it is :(