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 BCDF424728E; Mon, 23 Jun 2025 13:41:26 +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=1750686086; cv=none; b=TirFTxsFfKXzhYFZ0KT/32AOty2v7c7sHNPj2NYKHoo4iZGfluhR+4zXI5UWK9kJQlTAYceMImGp/YjgyJQphXjYwXa0FVCvQoQ8rQoNDyV9z2gPc1ZCSK6C5ZWaRn7WELpaZR6bM8TKJOc8sEKgPFaiP0nBJRUm5s3g6rFCOtQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750686086; c=relaxed/simple; bh=BMk99MlMjTrvBkk/Yv9RxOYHvhadQOQHD3htWtCr6oA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=duxs1ZsXTWkHVTWp9GmqDyFIqi0Uh0wuk1rUHNHMeNpzEf/WfXz4edqiJpaR347kPK65BsSu27jw6YXjNVn4YfuDxrQni9/BaxRNJHEmH271CPh5RoMoSdvFBn5ugTU0Zk3DVHGXSyqgr1y6ayp5PU8Po77PDZfkXedJkI2o0JI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0AxKxfYc; 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="0AxKxfYc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 512FAC4CEEA; Mon, 23 Jun 2025 13:41:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750686086; bh=BMk99MlMjTrvBkk/Yv9RxOYHvhadQOQHD3htWtCr6oA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0AxKxfYcxpKLvme5bA+v9j1dVrmjD/GwX3W7Y6egKfawTD8u2XS+tC9BZIKZdmJFj nSIXNnlIMLA/76mGxKcddUuaSUxjM0KtBbt6rH6RJ1CW7gUaAFAXxSV76dX3x3pIC1 R2FR/JeTqlgOS2C45IY1zimutg4wET2Nc7nsDzjo= 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 , Sasha Levin Subject: [PATCH 5.10 089/355] rtc: Fix offset calculation for .start_secs < 0 Date: Mon, 23 Jun 2025 15:04:50 +0200 Message-ID: <20250623130629.478467508@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250623130626.716971725@linuxfoundation.org> References: <20250623130626.716971725@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Mergnat [ Upstream commit fe9f5f96cfe8b82d0f24cbfa93718925560f4f8d ] 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: Sasha Levin --- drivers/rtc/class.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 625effe6cb65f..b1ce3bd724b2c 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -314,7 +314,7 @@ static void rtc_device_get_offset(struct rtc_device *rtc) * * 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) -- 2.39.5