From: Paolo Abeni <pabeni@redhat.com>
To: Erni Sri Satya Vennela <ernis@linux.microsoft.com>,
kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
decui@microsoft.com, longli@microsoft.com, andrew+netdev@lunn.ch,
davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
dipayanroy@linux.microsoft.com, horms@kernel.org,
kees@kernel.org, shacharr@microsoft.com,
stephen@networkplumber.org, linux-hyperv@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer
Date: Tue, 19 May 2026 13:00:04 +0200 [thread overview]
Message-ID: <8a33f35a-195a-4f1f-9282-85f68399b89f@redhat.com> (raw)
In-Reply-To: <20260514194156.466823-1-ernis@linux.microsoft.com>
On 5/14/26 9:41 PM, Erni Sri Satya Vennela wrote:
> In mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from
> DMA-coherent memory and bounds-checked, then mana_hwc_handle_resp()
> re-reads the same field from the same DMA buffer for test_bit() and
> pointer arithmetic.
>
> DMA-coherent memory is mapped uncacheable on x86 and is shared,
> unencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes
> directly to host-visible memory. A H/W can modify the value
> between the check and the use, bypassing the bounds validation.
Sashiko noted there are more related issues in the nearby code:
https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260514194156.466823-1-ernis%40linux.microsoft.com
you may consider a follow-up.
/P
next prev parent reply other threads:[~2026-05-19 11:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-14 19:41 [PATCH net] net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer Erni Sri Satya Vennela
2026-05-15 19:44 ` sashiko-bot
2026-05-18 11:38 ` Erni Sri Satya Vennela
2026-05-19 11:00 ` Paolo Abeni [this message]
2026-05-19 11:10 ` patchwork-bot+netdevbpf
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