From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Menzel , Guenter Roeck , Sasha Levin Subject: [PATCH 4.14 013/217] hwmon: (nct6775) Fix loop limit Date: Thu, 23 Aug 2018 09:52:06 +0200 Message-Id: <20180823075506.152846666@linuxfoundation.org> In-Reply-To: <20180823075505.090246914@linuxfoundation.org> References: <20180823075505.090246914@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guenter Roeck [ Upstream commit 91bb8f45f73f19a0150c233c0f11cdeb6d71d1e9 ] Commit cc66b3038254 ("hwmon: (nct6775) Rework temperature source and label handling") changed a loop limit from "data->temp_label_num - 1" to "32", as part of moving from a string array to a bit mask. This results in the following error, reported by UBSAN. UBSAN: Undefined behaviour in drivers/hwmon/nct6775.c:4179:27 shift exponent 32 is too large for 32-bit type 'long unsigned int' Similar to the original loop, the limit has to be one less than the number of bits. Fixes: cc66b3038254 ("hwmon: (nct6775) Rework temperature source and label handling") Reported-by: Paul Menzel Cc: Paul Menzel Tested-by: Paul Menzel Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/hwmon/nct6775.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/hwmon/nct6775.c +++ b/drivers/hwmon/nct6775.c @@ -4107,7 +4107,7 @@ static int nct6775_probe(struct platform * The temperature is already monitored if the respective bit in * is set. */ - for (i = 0; i < 32; i++) { + for (i = 0; i < 31; i++) { if (!(data->temp_mask & BIT(i + 1))) continue; if (!reg_temp_alternate[i])