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 23C0524EF8C; Mon, 23 Jun 2025 13:27:29 +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=1750685250; cv=none; b=r7rb/jIwrdSjPCwVYkCTWne/HX1asS/HpU+M6lDqCgIBfErpJ+2rzrTfa5lnkbf9YCyy7SoCQhRNyzZBlf6SFKBXYVYd2JnhNPmTdR1CGHQ/45uwWKObPa5a8zy7HmOQ/xUvOdcLJaOMaF+MHspUBSCZlA+m3cQxj4S5pmcZhjA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750685250; c=relaxed/simple; bh=OYUwpms9Dsap5deIkXdK+wsDPV8Asv2Coyhu0UZVUEA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tcZQggbDMy5ygMuZSvCgFRvvvcj4oBVtKyHafPTGc64kxvoYzBPlhG/YslfMhNbl2dy2CoKFGUoQlD/dPuH5FUdaffEr5bj3Nt/0hTh6c0Vf3ex5rphPsbi7LWRt5nnBNdQD3UTHZCjF4GHzS12+sDF3aWWy3XBsQy9KY0n9x0w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=W0hl76ww; 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="W0hl76ww" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5962CC4CEEA; Mon, 23 Jun 2025 13:27:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750685249; bh=OYUwpms9Dsap5deIkXdK+wsDPV8Asv2Coyhu0UZVUEA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W0hl76wwVnFGS7EP+yTQhOjeA/6s1WRd+VY3hgm7Z+sZ7GJ8itEeHxv6+uPH9T823 OaPek5ojvIZ00jz/OWSEhoZvnd5GL6QWELk8iKKZXlTZfoaOqtN15gLmY9GxSZzNeK Wmrsp3Cu6VVyoGBSQB74igmVf7vVMws4xO0jtiwU= 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 5.15 006/411] rtc: Fix offset calculation for .start_secs < 0 Date: Mon, 23 Jun 2025 15:02:30 +0200 Message-ID: <20250623130633.184293373@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250623130632.993849527@linuxfoundation.org> References: <20250623130632.993849527@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 5.15-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 @@ -322,7 +322,7 @@ 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)