From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E0471F4CB8; Sat, 7 Jun 2025 10:10:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749291037; cv=none; b=JYEFnJOnhD15qv7Ha88dUc2vdulRUbV9ITKwjoTcjW/0ZmIr+nBck+cTyTwlOKtjDynnxqAQ6hBIU27ilLLPuQfJyoUgtWbVDFj1NXilFJpmuD1nMoHkBRe6nDeiF3mqpFNqc4ov6qsqUyQx8ehzGNA8Y39R8R2SSro5DdHKqXM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749291037; c=relaxed/simple; bh=9ErGhhli9UzoIUoyBKf42/n+eEx1hOtK5K8gqSd0ZZU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CFfnPOku48RsJsTJz7t+VfNsHgJygO6WkfIpWaTzLbxyC1BnRJBZz/MWB9WGUNCPtsTCfkt3fV6yqmZdEYgzJ+7OFiiT016x3JehQ0J9VQX72+X+Ut6K6jlh3vFpOvTONVE3t6jCN/4eDV++Wduqw896rRYouIaE/JADC6aH+Vw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hYb/0m+e; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hYb/0m+e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2448C4CEE4; Sat, 7 Jun 2025 10:10:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1749291037; bh=9ErGhhli9UzoIUoyBKf42/n+eEx1hOtK5K8gqSd0ZZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hYb/0m+e73VMmgeHbRuxxNMIyO+dBR8GKHZoe0zFFXu12kgp1DC/wU7lyXLTTV9Zz A2eKrhSASBRiPEe/mO9fM1txrEI2N20oSscpuAm1v596hN+g6y0IfNAKJIEJPRtSzh E6liE5xkVe1fyN8eHhYIfTG9TKK5cjOtZQGIKkhs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexandre Mergnat , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Alexandre Belloni Subject: [PATCH 6.15 13/34] rtc: Fix offset calculation for .start_secs < 0 Date: Sat, 7 Jun 2025 12:07:54 +0200 Message-ID: <20250607100720.240415759@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250607100719.711372213@linuxfoundation.org> References: <20250607100719.711372213@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Mergnat commit fe9f5f96cfe8b82d0f24cbfa93718925560f4f8d upstream. The comparison rtc->start_secs > rtc->range_max has a signed left-hand side and an unsigned right-hand side. So the comparison might become true for negative start_secs which is interpreted as a (possibly very large) positive value. As a negative value can never be bigger than an unsigned value the correct representation of the (mathematical) comparison rtc->start_secs > rtc->range_max in C is: rtc->start_secs >= 0 && rtc->start_secs > rtc->range_max Use that to fix the offset calculation currently used in the rtc-mt6397 driver. Fixes: 989515647e783 ("rtc: Add one offset seconds to expand RTC range") Signed-off-by: Alexandre Mergnat Reviewed-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20250428-enable-rtc-v4-2-2b2f7e3f9349@baylibre.com Signed-off-by: Alexandre Belloni Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/class.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -326,7 +326,7 @@ static void rtc_device_get_offset(struct * * Otherwise the offset seconds should be 0. */ - if (rtc->start_secs > rtc->range_max || + if ((rtc->start_secs >= 0 && rtc->start_secs > rtc->range_max) || rtc->start_secs + range_secs - 1 < rtc->range_min) rtc->offset_secs = rtc->start_secs - rtc->range_min; else if (rtc->start_secs > rtc->range_min)