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From: Eric Biggers <ebiggers@kernel.org>
To: Nick Terrell <terrelln@fb.com>
Cc: syzbot <syzbot+1f2eb3e8cd123ffce499@syzkaller.appspotmail.com>,
	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com,
	linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
	terrelln@fb.com, linux-hardening@vger.kernel.org
Subject: Re: [syzbot] [zstd] UBSAN: array-index-out-of-bounds in FSE_decompress_wksp_body_bmi2
Date: Sat, 7 Oct 2023 14:05:56 -0700	[thread overview]
Message-ID: <20231007210556.GA174883@sol.localdomain> (raw)
In-Reply-To: <00000000000049964e06041f2cbf@google.com>

Hi Nick,

On Wed, Aug 30, 2023 at 12:49:53AM -0700, syzbot wrote:
> UBSAN: array-index-out-of-bounds in lib/zstd/common/fse_decompress.c:345:30
> index 33 is out of range for type 'FSE_DTable[1]' (aka 'unsigned int[1]')

Zstandard needs to be converted to use C99 flex-arrays instead of length-1
arrays.  https://github.com/facebook/zstd/pull/3785 would fix this in upstream
Zstandard, though it doesn't work well with the fact that upstream Zstandard
supports C90.  Not sure how you want to handle this.

- Eric

  reply	other threads:[~2023-10-07 21:06 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-30  7:49 [syzbot] [btrfs?] UBSAN: array-index-out-of-bounds in FSE_decompress_wksp_body_bmi2 syzbot
2023-10-07 21:05 ` Eric Biggers [this message]
2023-10-09 17:29   ` [syzbot] [zstd] " Kees Cook
2023-10-12 19:55     ` Nick Terrell
2023-10-12 20:13       ` Kees Cook
2023-10-12 20:23         ` Nick Terrell

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