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 5FEA151FCCE; Wed, 30 Sep 2026 18:27:43 +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=1790792864; cv=none; b=GPPwk+CGcyY3EpJBLNXmRzEP78A1ugQx9lm7GiHowproysaRZwSxCMqRZTXu5SdaHUxLWUd/LPcMC1JMxjZTr564fGYLrNjjjHlURa4MedzarhEj0SzySzLcq2KowQX791RL0478O6dd1lzVOh6HJsTCEgdIWHvxf9oImz54JKo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792864; c=relaxed/simple; bh=bA2sGCtxrJvAPqfh2mNSjQcT/xbQMCFtxaO9vAmPDkY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WWJ3+6wmpl8Gc/Dh6UQlpPfGWZx/NmawjAJb419Dsvw/YiLYQZf78ohyBtmH4RvkBDkBGGUCzEDtYBeOWXkIEKPayQ8b+vBCmkCfGvRkfmUj/AKpbvcpirj4ujEaQILXUW9rMsAPy1B5DvtOA7QfEE16AsCzmZ2TMZGhyZ21zHI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=scSPcAp5; 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="scSPcAp5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA5D91F000FF; Wed, 30 Sep 2026 18:27:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790792863; bh=72oU6ZW98SaO0apCXxmzmkl/Z+bP4ZLsRwNdFenndYs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=scSPcAp549RSB8GWdgKqu7mCTjY6QXF5sNIzT7YanLWVtI68rvqV+YbMSYmHDfPzi 08uXrukbx1wU/e5JApeyNmdQZMsEe26lUOk+bEbq+GpxEdnl0Td4JNYhumyrYozYmm GQLzynVAaQXpPBJcf0mSCuZ9j+jaUMrVRfAp/IOY= 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 6.18 052/395] s390/cio: Fix cio_update_schib() to not cache invalid schib Date: Wed, 30 Sep 2026 17:25:14 +0200 Message-ID: <20260930152341.765128205@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152340.591469096@linuxfoundation.org> References: <20260930152340.591469096@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vineeth Vijayan [ Upstream commit 29d9e5835d89223aa913dcf7b942cc1c148bdd25 ] When pmcw.dnv is 0, the contents of all SCHIB fields are unpredictable. Zero sch->schib in that case to prevent subsequent code from making decisions based on unpredictable data. 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/cio.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c index 21508e4606d59..20ebe0d883c64 100644 --- a/drivers/s390/cio/cio.c +++ b/drivers/s390/cio/cio.c @@ -454,7 +454,8 @@ EXPORT_SYMBOL_GPL(cio_commit_config); /** * cio_update_schib - Perform stsch and update schib if subchannel is valid. * @sch: subchannel on which to perform stsch - * Return zero on success, -ENODEV otherwise. + * Return zero on success, -ENODEV if the subchannel is not operational, + * -EACCES if the subchannel has no valid device. */ int cio_update_schib(struct subchannel *sch) { @@ -463,10 +464,12 @@ int cio_update_schib(struct subchannel *sch) if (stsch(sch->schid, &schib)) return -ENODEV; - memcpy(&sch->schib, &schib, sizeof(schib)); - - if (!css_sch_is_valid(&schib)) + if (!css_sch_is_valid(&schib)) { + memset(&sch->schib, 0, sizeof(sch->schib)); return -EACCES; + } + + memcpy(&sch->schib, &schib, sizeof(schib)); return 0; } -- 2.53.0