From mboxrd@z Thu Jan 1 00:00:00 1970 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 C9B07EEB57B for ; Sat, 9 Sep 2023 01:23:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235187AbjIIBXb (ORCPT ); Fri, 8 Sep 2023 21:23:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240888AbjIIAoN (ORCPT ); Fri, 8 Sep 2023 20:44:13 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 288F030D7; Fri, 8 Sep 2023 17:41:38 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8044C116AC; Sat, 9 Sep 2023 00:41:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694220078; bh=+P//p41L4AtomOnxSnRhn0lU105Wn2sA2lUZ9XmQegQ=; h=From:To:Cc:Subject:Date:From; b=Tz0D4p3oAkXoQz0KwbMHV6vvLVgqQr3c9UsNdrHS7/EsJw8nQeFY4QeUHvTxK8+iy KRWcz7uRkJvlkgEuFw4mzTVVd4qItMFG/OFQ/mLvKz0FJ9W/KdgCcStJON8yQp4HuT fWSUP+5DXxOssmJ1mSZX15iDxnzNXEeEhJriieu6yHqT5zQZP9kAbVn8Rm2iByQEQT FA90c0AiOOioRB4TuUPz/Y5iQvN7up1BX7tfGyHk8EZf1ORKHfd6ELfUb2CqGyi2RB 6aBeDU08cWF+x0i6hcxrvjHJ8x4HHXAzBbYB/QznCUeY6gs63LD3SXEYZQy9oVQkaT fQRZbmBTbLU1w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhang Shurong , Hans Verkuil , Sasha Levin , crope@iki.fi, mchehab@kernel.org, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 01/12] media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer Date: Fri, 8 Sep 2023 20:41:04 -0400 Message-Id: <20230909004115.3581195-1-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.14.325 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhang Shurong [ Upstream commit 7bf744f2de0a848fb1d717f5831b03db96feae89 ] In af9035_i2c_master_xfer, msg is controlled by user. When msg[i].buf is null and msg[i].len is zero, former checks on msg[i].buf would be passed. Malicious data finally reach af9035_i2c_master_xfer. If accessing msg[i].buf[0] without sanity check, null ptr deref would happen. We add check on msg[i].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()") Signed-off-by: Zhang Shurong Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb-v2/af9035.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/media/usb/dvb-usb-v2/af9035.c b/drivers/media/usb/dvb-usb-v2/af9035.c index 1f6c1eefe3892..55c7e7348869b 100644 --- a/drivers/media/usb/dvb-usb-v2/af9035.c +++ b/drivers/media/usb/dvb-usb-v2/af9035.c @@ -336,6 +336,8 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, ret = -EOPNOTSUPP; } else if ((msg[0].addr == state->af9033_i2c_addr[0]) || (msg[0].addr == state->af9033_i2c_addr[1])) { + if (msg[0].len < 3 || msg[1].len < 1) + return -EOPNOTSUPP; /* demod access via firmware interface */ u32 reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | msg[0].buf[2]; @@ -395,6 +397,8 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, ret = -EOPNOTSUPP; } else if ((msg[0].addr == state->af9033_i2c_addr[0]) || (msg[0].addr == state->af9033_i2c_addr[1])) { + if (msg[0].len < 3) + return -EOPNOTSUPP; /* demod access via firmware interface */ u32 reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | msg[0].buf[2]; @@ -402,10 +406,7 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, if (msg[0].addr == state->af9033_i2c_addr[1]) reg |= 0x100000; - ret = (msg[0].len >= 3) ? af9035_wr_regs(d, reg, - &msg[0].buf[3], - msg[0].len - 3) - : -EOPNOTSUPP; + ret = af9035_wr_regs(d, reg, &msg[0].buf[3], msg[0].len - 3); } else { /* I2C write */ u8 buf[MAX_XFER_SIZE]; -- 2.40.1