From: sashiko-bot@kernel.org
To: "Fang Xieyan" <fangxy@xiaopeng.com>
Cc: kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
virtualization@lists.linux.dev,
"Eugenio Perez" <eperezma@redhat.com>
Subject: Re: [PATCH] vringh: reject empty / undersized indirect descriptor tables
Date: Thu, 24 Sep 2026 03:13:53 +0000 [thread overview]
Message-ID: <20260924031354.1C8721F0089A@smtp.kernel.org> (raw)
In-Reply-To: <20260924030627.13287-1-fangxy@xiaopeng.com>
> move_to_indirect() rejects an indirect descriptor table only when its
> length is not an exact multiple of sizeof(struct vring_desc). A guest
> descriptor with VRING_DESC_F_INDIRECT and len == 0 passes that check, so
> *desc_max becomes 0, yet __vringh_iov() keeps walking the (empty) table
> and aborts with -ELOOP only after reading one full descriptor past its
> end -- leaking 16 bytes of memory adjacent to the table into a kernel
> stack variable.
>
> Reject any len smaller than one descriptor, before the existing stride
> check, so no descriptor is ever fetched from an empty table.
>
> Fixes: f87d0fbb5798 ("vringh: host-side implementation of virtio rings.")
> Cc: stable@vger.kernel.org
> Assisted-by: Hawkeye:GLM-5.3-flash
> Assisted-by: Qoder:Qwen3.8-Max
> Signed-off-by: Fang Xieyan <fangxy@xiaopeng.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260924030627.13287-1-fangxy@xiaopeng.com?part=1
next prev parent reply other threads:[~2026-09-24 3:13 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-24 3:06 [PATCH] vringh: reject empty / undersized indirect descriptor tables Fang Xieyan
2026-09-24 3:13 ` sashiko-bot [this message]
2026-09-24 15:56 ` Michael S. Tsirkin
2026-09-26 16:07 ` [PATCH v2] " Fang Xieyan
2026-09-26 16:16 ` sashiko-bot
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