From patchwork Fri May 17 15:58:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikita Zhandarovich X-Patchwork-Id: 13667159 Received: from exchange.fintech.ru (exchange.fintech.ru [195.54.195.159]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C9A112FB12; Fri, 17 May 2024 15:58:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.54.195.159 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715961497; cv=none; b=OkV1BBq+OPNx0SNrD8g+elt7C0skt4ocslgBa+JWL1HkUWqT9OzF9TbHoUoNnAxTpS7knWN8+Ak3+b6Or2cMIyrYKSxlAOCxLuofAzYqFqBpsGKZcXXERfhi1mVYRf5f9DGZ1VrJCqOz8DykfZ7GIZ0FRQ896Zu/Q7S4mAzOMVU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715961497; c=relaxed/simple; bh=jPs7IHbfPkYSUHCi80uToaFuP+PivAQ4suilrpSf6d0=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=Lew5scVLwuXsblXIFM+xjT3Z+czN2I+ILoxbgWrypHWv0WXQh9v++AJDal3AqnVN+fvUrEw7Qz0U1WoN/JEIYbR0/IzU7hCooFg28p4MYyUZ3oA0jS9Sc8C7Zd2x43TdgfLPuX8Vl1O7WEDCAtHM9dMDo5E4k4l7bIY2LnS4fyo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fintech.ru; spf=pass smtp.mailfrom=fintech.ru; arc=none smtp.client-ip=195.54.195.159 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fintech.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fintech.ru Received: from Ex16-01.fintech.ru (10.0.10.18) by exchange.fintech.ru (195.54.195.169) with Microsoft SMTP Server (TLS) id 14.3.498.0; Fri, 17 May 2024 18:58:10 +0300 Received: from localhost (10.0.253.138) by Ex16-01.fintech.ru (10.0.10.18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Fri, 17 May 2024 18:58:10 +0300 From: Nikita Zhandarovich To: Mauro Carvalho Chehab , Hans Verkuil CC: Nikita Zhandarovich , Luis Chamberlain , Greg Kroah-Hartman , "Patrick Boettcher" , , , Subject: [PATCH] media: dvb-frontends: dib3000mb: fix uninit-value in dib3000_write_reg Date: Fri, 17 May 2024 08:58:00 -0700 Message-ID: <20240517155800.9881-1-n.zhandarovich@fintech.ru> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: Ex16-02.fintech.ru (10.0.10.19) To Ex16-01.fintech.ru (10.0.10.18) Syzbot reports [1] an uninitialized value issue found by KMSAN in dib3000_read_reg(). Local u8 rb[2] is used in i2c_transfer() as a read buffer; in case that call fails, the buffer may end up with some undefined values. Since no elaborate error handling is expected in dib3000_write_reg(), simply zero out rb buffer to mitigate the problem. [1] Syzkaller report dvb-usb: bulk message failed: -22 (6/0) ===================================================== BUG: KMSAN: uninit-value in dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758 dib3000mb_attach+0x2d8/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758 dibusb_dib3000mb_frontend_attach+0x155/0x2f0 drivers/media/usb/dvb-usb/dibusb-mb.c:31 dvb_usb_adapter_frontend_init+0xed/0x9a0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:290 dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:90 [inline] dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:186 [inline] dvb_usb_device_init+0x25a8/0x3760 drivers/media/usb/dvb-usb/dvb-usb-init.c:310 dibusb_probe+0x46/0x250 drivers/media/usb/dvb-usb/dibusb-mb.c:110 ... Local variable rb created at: dib3000_read_reg+0x86/0x4e0 drivers/media/dvb-frontends/dib3000mb.c:54 dib3000mb_attach+0x123/0x3c0 drivers/media/dvb-frontends/dib3000mb.c:758 ... Fixes: 74340b0a8bc6 ("V4L/DVB (4457): Remove dib3000-common-module") Reported-by: syzbot+c88fc0ebe0d5935c70da@syzkaller.appspotmail.com Signed-off-by: Nikita Zhandarovich --- drivers/media/dvb-frontends/dib3000mb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/dvb-frontends/dib3000mb.c b/drivers/media/dvb-frontends/dib3000mb.c index c598b2a63325..7c452ddd9e40 100644 --- a/drivers/media/dvb-frontends/dib3000mb.c +++ b/drivers/media/dvb-frontends/dib3000mb.c @@ -51,7 +51,7 @@ MODULE_PARM_DESC(debug, "set debugging level (1=info,2=xfer,4=setfe,8=getfe (|-a static int dib3000_read_reg(struct dib3000_state *state, u16 reg) { u8 wb[] = { ((reg >> 8) | 0x80) & 0xff, reg & 0xff }; - u8 rb[2]; + u8 rb[2] = {}; struct i2c_msg msg[] = { { .addr = state->config.demod_address, .flags = 0, .buf = wb, .len = 2 }, { .addr = state->config.demod_address, .flags = I2C_M_RD, .buf = rb, .len = 2 },