From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 93FBC3E022B; Wed, 30 Sep 2026 19:30:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796642; cv=none; b=ufKmsN8Ejfv+feDzp4/llgHdtFjn9p6QGKJ6uYpGKdvzfXF6fRVxQLnmWXbjR3JHIGNyNPTvpzL/KtHc27ULr9FaO+PkWuo++tCHQWrRp6FUvJzkXfbSDjI/a3DKmXnw21tMHALWH0M3P+LJd8RVyI5Qk8cXdseIXvvFevmct3w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796642; c=relaxed/simple; bh=eAcSoQuaDRGeU5uzvTGP7pEfs+UqRE5EkGGHt1giFG4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DgZMQr/gZwat6+JR4O7+zXn94gQSdrRTMOucEFSG+jKJxmDAj3BLm1B9XgO9NCGjr8gFRTUwpeTA15AV6yt5BvWIGj6LvbRZnflKSOxuepeNUsHm+V/meUkx+rQXkAu5yEWkWuMNcDIa0YuLPHvH7nQWBmMCKPhqP9XXSJ3RQRc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WLSnFDCM; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="WLSnFDCM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E29B41F000FF; Wed, 30 Sep 2026 19:30:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790796641; bh=Um+YAH4GgSclFWRath0UB1Aa89XiOckPA6tkHuZE9W4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WLSnFDCMPFxhasyN5qe3Vcvn7nlnToTkbW4iJgAxxaNE0Acw8suYJksnP9ZR2CZfi Ytpkr8ih3bF/8SDMRNx+b0osOUouanFY5jyU6tS9MKu2lVFLJ26yVI7KAPgouxS3CZ 0UHCOyNjTtK4TncCqF7G0pWqNRSv+B9/TePlDfbY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, William Bezenah , Vineeth Vijayan , Peter Oberparleiter , Heiko Carstens , Sasha Levin Subject: [PATCH 6.6 0984/1193] s390/cio: Check pmcw.dnv before pmcw.ena in I/O entry points Date: Wed, 30 Sep 2026 17:27:48 +0200 Message-ID: <20260930152456.107423762@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@linuxfoundation.org> User-Agent: quilt/0.69 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-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vineeth Vijayan [ Upstream commit f6f2985eabdb2bfdc82ce90a1ea3ec53ba795f34 ] The device number valid (dnv) bit in the PMCW must be checked before acting on any other PMCW fields for IO-type subchannels. A subchannel with dnv=0 has no valid device number associated, making it meaningless to evaluate the enabled (ena) state or issue any I/O instruction against it. Reported-by: William Bezenah Signed-off-by: Vineeth Vijayan Reviewed-by: Peter Oberparleiter Fixes: 8c58a229688c ("s390/cio: Do not unregister the subchannel based on DNV") Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- drivers/s390/cio/device_ops.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c index a5dba3829769c..a18919a50909a 100644 --- a/drivers/s390/cio/device_ops.c +++ b/drivers/s390/cio/device_ops.c @@ -142,6 +142,8 @@ int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm) if (!cdev || !cdev->dev.parent) return -ENODEV; sch = to_subchannel(cdev->dev.parent); + if (!sch->schib.pmcw.dnv) + return -ENODEV; if (!sch->schib.pmcw.ena) return -EINVAL; if (cdev->private->state == DEV_STATE_NOT_OPER) @@ -198,6 +200,8 @@ int ccw_device_start_timeout_key(struct ccw_device *cdev, struct ccw1 *cpa, if (!cdev || !cdev->dev.parent) return -ENODEV; sch = to_subchannel(cdev->dev.parent); + if (!sch->schib.pmcw.dnv) + return -ENODEV; if (!sch->schib.pmcw.ena) return -EINVAL; if (cdev->private->state == DEV_STATE_NOT_OPER) @@ -375,6 +379,8 @@ int ccw_device_halt(struct ccw_device *cdev, unsigned long intparm) if (!cdev || !cdev->dev.parent) return -ENODEV; sch = to_subchannel(cdev->dev.parent); + if (!sch->schib.pmcw.dnv) + return -ENODEV; if (!sch->schib.pmcw.ena) return -EINVAL; if (cdev->private->state == DEV_STATE_NOT_OPER) @@ -409,6 +415,8 @@ int ccw_device_resume(struct ccw_device *cdev) if (!cdev || !cdev->dev.parent) return -ENODEV; sch = to_subchannel(cdev->dev.parent); + if (!sch->schib.pmcw.dnv) + return -ENODEV; if (!sch->schib.pmcw.ena) return -EINVAL; if (cdev->private->state == DEV_STATE_NOT_OPER) @@ -544,6 +552,8 @@ int ccw_device_tm_start_timeout_key(struct ccw_device *cdev, struct tcw *tcw, int rc; sch = to_subchannel(cdev->dev.parent); + if (!sch->schib.pmcw.dnv) + return -ENODEV; if (!sch->schib.pmcw.ena) return -EINVAL; if (cdev->private->state == DEV_STATE_VERIFY) { @@ -686,6 +696,8 @@ int ccw_device_tm_intrg(struct ccw_device *cdev) { struct subchannel *sch = to_subchannel(cdev->dev.parent); + if (!sch->schib.pmcw.dnv) + return -ENODEV; if (!sch->schib.pmcw.ena) return -EINVAL; if (cdev->private->state != DEV_STATE_ONLINE) -- 2.53.0