From nobody Thu Apr 2 04:22:54 2026 Received: from mail-vk1-f173.google.com (mail-vk1-f173.google.com [209.85.221.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D89335DA60 for ; Mon, 30 Mar 2026 13:29:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.173 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774877369; cv=none; b=KH3+ebLK9NZ/EVJpFx7Lp1+Cl1+qcV1E18FZOL1DXkBgVNw5fn1F4w5Aaqqkm2oaGxmD2VS2jlo3xj7NstVivzPUG1i8en5WYQMhaKHaHCetsLuPQSJYWgI82VWWcEMotJ8nT+VGuT2sxlX51DGBbPcHxO8oR9mT1XTCKw1kC64= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774877369; c=relaxed/simple; bh=HMPY83hDOtEh2uH8sesLzoJ/Zhf64/JSuRtvJ9f2po4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=AQMGk5e/5RI2lbWRFSdEQ4y3M06UkyJCZ8MOMzL0X13WPOldWSinTh19V24iUb8hhWbYgX1XRyxbjh50ZEEQ1DY4PZBOdFoa8bAUdifxofxCGGtzkvYm6VeIcE+7eCSiF4EEdZkH2pESU77+HxHxvaVL3eZ5PO5pg88dO5Bo9gw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=pwxvW0uV; arc=none smtp.client-ip=209.85.221.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pwxvW0uV" Received: by mail-vk1-f173.google.com with SMTP id 71dfb90a1353d-56ba039eecbso1550065e0c.0 for ; Mon, 30 Mar 2026 06:29:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1774877367; x=1775482167; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=26QADu2V5kInSwvDprX/X5k3HI6g/YNPM7XdH9A3Fig=; b=pwxvW0uVskulGYZtE7CZVzUfPj3e1yDwTiMO4bFq7V0qVX3jOkLUQYljhY6K4zwCh2 /ZuNPDjHVfnQMCldyDPhWKtFxM+Z/mrmQ/OoyBpGTo3SqL0k/d5AHdWQRS1rk7BltB8p /RLdGilAA+f99F+QXJavlaYM5+kkUQS4FAvnkBfO+hj025/4e+n3FkZGaoNASiDNzSeA nD/4g84s2oGyzTDAEt2cFdhzu59dg2t/ltggYeqlgQ/WKijNjypFnQUWxNKEpAPRtvKP PCUk6khYeZ77o0RrDx4fU8jKRXFrgRFC724o+gHjuNvFJOgmcKuHh6vnJpzZ0lv1A45i gMcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774877367; x=1775482167; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=26QADu2V5kInSwvDprX/X5k3HI6g/YNPM7XdH9A3Fig=; b=MJTAtKOwDFPldSOBI3N0VD8OJbS7KhaQJgh6/u1hU/oWjvP1Mm9TAiDUMyQgf67diX 5UWEYVrXTXk2CQ0qPMz5/CVtMhg4AKYp7NaGJ1zlDmVqJCjmZo33c6x4iSGDBI8Q/oC3 j1skaXfAQUpxszuVOXo3S5odR6a29HKzGDQSGq2TCKP23XGjia98RWrwP9YamsyqkAkz 6K/Aa667vjgT7yN8HEjNEd/qiD1zltjx2auq7hf551Bci9rhlraG5MbiwnBwUc96k2wW aUXSdylz64o8wayYL8Cuf501V/IUDy27Y55rVmMliyM1diZJV7EXN5vasCkhaz5pkUA3 FWdg== X-Forwarded-Encrypted: i=1; AJvYcCUih9bac4RCxNrIrzTDITUJT3TN3yZyMDSL6F1ReTzNH8D4M5TBmElVuLgyt/hyrtw/auHgaAITuus3Cfk=@vger.kernel.org X-Gm-Message-State: AOJu0YzsU/Drrt/WeU7qFCa7LKWrB+xTHxHLmr+XmOa8jUJkkCijVRrn I3KwkguQomsln0TU32GqotYvi5JmGBgxbU5jhpTUbi2SNedPUWUMoV/H X-Gm-Gg: ATEYQzwClHuhLi1J6k0AjjyyXfvRlUNu37m0SeBaVulgvbFI2EU8N9+bIApfX6ingS2 KHl6tHv7CFLbBU2Hvi8DiFJbSUTGQXf9GUqViVUgmQzRiLVAYgpEM4kMFlFcV4+uNpoikC33fjj IwgpKyiykdbE1iz9S/y7HQkCiJHYqwRZIaAITHdjv2ehg1nTQ81+lN+HWuIP2mWdPRJWh1Krtk3 XF4wygtR3vVVej1E26KrUvY7VLsDa/ubZAp7zRgx09m9PUOhGmtFEyqTiEW2TpLJco+zbaTc8Di QpxxJ/ROr9shBpIo9dDzOPH1eSCy7h6uK+0Ro8bWPzipR9GxRb34AQiay4BGuCZ0f+xFgXYuYiw lkEtkORbfRc2m5JsIqrOjNT9uLhIuHxr89IgvginHlkWvfYdZdmL7Bi7O8WDDqMFCvcdYzPgtmN uEWDOczsq/5hV93SgdBbyxoa4= X-Received: by 2002:a05:6122:1801:b0:56a:9841:9f81 with SMTP id 71dfb90a1353d-56d4a51961cmr4233767e0c.6.1774877366946; Mon, 30 Mar 2026 06:29:26 -0700 (PDT) Received: from localhost.localdomain ([2a09:bac6:d6d9:aa::11:1d6]) by smtp.gmail.com with ESMTPSA id 71dfb90a1353d-56d588c4016sm8333474e0c.8.2026.03.30.06.29.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Mar 2026 06:29:26 -0700 (PDT) From: Sebastian Josue Alba Vives To: jikos@kernel.org, bentiss@kernel.org Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sebastian Josue Alba Vives Subject: [PATCH v2] HID: mcp2221: validate report size in raw_event handler Date: Mon, 30 Mar 2026 07:29:22 -0600 Message-ID: <20260330132922.827503-1-sebasjosue84@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" mcp2221_raw_event() accesses the data buffer at offsets up to 55 without validating the size parameter. Since __hid_input_report() invokes the driver's raw_event callback before hid_report_raw_event() performs its own report-size validation, a device sending a truncated HID report can cause out-of-bounds heap reads in the kernel. The most critical access is the memcpy from data[50] into mcp->adc_values (6 bytes) when CONFIG_IIO is reachable. Other unchecked accesses include data[20] and a memcpy at data[22]. Additionally, a memcpy with device-controlled length (data[3], up to 60 bytes) from data[4] does not verify that size is large enough to cover the copy. MCP2221 devices use 64-byte HID reports. Add a check at the top of the handler to reject any report shorter than expected, and log a warning to aid debugging. Cc: stable@vger.kernel.org Signed-off-by: Sebastian Josue Alba Vives --- drivers/hid/hid-mcp2221.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c index ef3b5c77c..770c305d8 100644 --- a/drivers/hid/hid-mcp2221.c +++ b/drivers/hid/hid-mcp2221.c @@ -850,6 +850,11 @@ static int mcp2221_raw_event(struct hid_device *hdev, { u8 *buf; struct mcp2221 *mcp =3D hid_get_drvdata(hdev); + /* MCP2221 always sends 64-byte reports */ + if (size < 64) { + hid_warn(hdev, "report too short: %d < 64\n", size); + return 0; + } =20 switch (data[0]) { =20 --=20 2.43.0