From nobody Wed Apr 15 00:04:42 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7C3BC00144 for ; Fri, 29 Jul 2022 09:35:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235244AbiG2JfE (ORCPT ); Fri, 29 Jul 2022 05:35:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231578AbiG2JfC (ORCPT ); Fri, 29 Jul 2022 05:35:02 -0400 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2614140B1 for ; Fri, 29 Jul 2022 02:35:01 -0700 (PDT) Received: by mail-pg1-x534.google.com with SMTP id bf13so3584572pgb.11 for ; Fri, 29 Jul 2022 02:35:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=OVF3y7QB8gY+KNNuUfkiCKf/IXKM8mP2Ri70A+tABKc=; b=Mg0AXzsUX+08glZ5ua8BKGJOWS9ZgPWopKBkPg3u3Mjahu2Ptdc689CwTbvUNQklCV 3b/sSwvG1BWHv+B+m+LE0qcph9ulUlqq47lpMbBrE9h8R4cCBmzq+Df1Xnmc/SyX23R4 YigcAS+ezWhEIjDa6jiQ5Fc0qXTDK5pKa+HE0h6J9eeUz0oSo0UEI+83GkdhpwKhx9h7 WvNqbZ6Emgk+OOGWdHxFIazxxMAhyayqJDqNNk2J4WUZRN9EvKxKTvYRlYqhf/NMA6uf 3/RAt6ejM/j5S1aatHw+cMLOLZD6Lqs9tGjChUywbhnwpe51gICrHs3+/4sf0Wm6NN+0 Qu9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=OVF3y7QB8gY+KNNuUfkiCKf/IXKM8mP2Ri70A+tABKc=; b=oMTfZqUNWS81tCNWKNO8znB6gguTTvKSAu+46d6VpsAo75IKXRGXXzmfnIgztv9Pty aK6/T0eTDQq4WcRpKEE9zAJP68fRB5dUJKNqRJEq9FnkfOxDg3p9ND9LcxxgpjxvtWOJ 40lcHOHAv2ASw//3KL7oXvFxvjXzcUNjMfCz5fnUaMdP9gdtsUQVBSlgiYQlaGJvKauf oFWu+OUjKWCXpUiegoaTgmdzpevmFWGIM5BGmNy3cwZ3TbTtuW+xMjUZaC9isPtQQbao gx5m/r14Ar1597EsSkw7P2yZL5DOIRn6JI6uppunv869l4y6rY5TGedtV+Nrcac/MVVS 82yQ== X-Gm-Message-State: AJIora8/1GGPWFLUMZZErKLDQBUaZw8y6ujB8WfLvfUiOr/jsKIfgRGV 2OFIVdeuSRZ1NzNbkst10A== X-Google-Smtp-Source: AGRyM1s1OBR0CdZueQ6wLASKBU/Xr85jaWW4z4VigRVFw0nPop5Rf+vD8b7gwmtamzJECFF6bsTYdA== X-Received: by 2002:a65:6e82:0:b0:41a:9b73:f0e6 with SMTP id bm2-20020a656e82000000b0041a9b73f0e6mr2297713pgb.371.1659087301099; Fri, 29 Jul 2022 02:35:01 -0700 (PDT) Received: from localhost.localdomain ([144.202.91.207]) by smtp.gmail.com with ESMTPSA id d8-20020a17090a7bc800b001f2ef3c7956sm5407398pjl.25.2022.07.29.02.34.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Jul 2022 02:35:00 -0700 (PDT) From: Zheyu Ma Cc: Zheyu Ma , linux-kernel@vger.kernel.org Subject: [PATCH] i2c: ismt: Fix an out-of-bounds bug in ismt_access() Date: Fri, 29 Jul 2022 17:34:51 +0800 Message-Id: <20220729093451.551672-1-zheyuma97@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When the driver does not check the data from the user, the variable 'data->block[0]' may be very large to cause an out-of-bounds bug. The following log can reveal it: [ 33.995542] i2c i2c-1: ioctl, cmd=3D0x720, arg=3D0x7ffcb3dc3a20 [ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE [ 33.996475] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b [ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 b= y task ismt_poc/485 [ 33.999450] Call Trace: [ 34.001849] memcpy+0x20/0x60 [ 34.002077] ismt_access.cold+0x374/0x214b [ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0 [ 34.004007] i2c_smbus_xfer+0x10a/0x390 [ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710 [ 34.005196] i2cdev_ioctl+0x5ec/0x74c Fix this bug by checking the size of 'data->block[0]' first. Fixes: 13f35ac14cd0 ("i2c: Adding support for Intel iSMT SMBus 2.0 host con= troller") Signed-off-by: Zheyu Ma --- drivers/i2c/busses/i2c-ismt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c index 6078fa0c0d48..63120c41354c 100644 --- a/drivers/i2c/busses/i2c-ismt.c +++ b/drivers/i2c/busses/i2c-ismt.c @@ -509,6 +509,9 @@ static int ismt_access(struct i2c_adapter *adap, u16 ad= dr, if (read_write =3D=3D I2C_SMBUS_WRITE) { /* Block Write */ dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n"); + if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX) + return -EINVAL; + dma_size =3D data->block[0] + 1; dma_direction =3D DMA_TO_DEVICE; desc->wr_len_cmd =3D dma_size; --=20 2.25.1