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 65F3F4ED196; Wed, 30 Sep 2026 16:50:01 +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=1790787002; cv=none; b=JI6CwdNDd9BJu2RHW47CmMk4Lty5el3gAj4HdWohxK3GahFfF+QBT5R6QAG3qCj6beCMjrWjJoIiZcy8aMT+t1lJM0t5DIoDxsXV96vru6L7IB3gERnOEaH7TbPcixPzSvEu4LdzdGoPlTe5MIFSXk0QmjHOgTeIYdiv4pI4kNQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790787002; c=relaxed/simple; bh=06khQTLxPhgwd5w1p9dZ7S10RIesHt4V7DkHadfnZng=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FNIiOCt96DbEfJaNb0GbzkhDpUFFNnaWqVJRdoNdeV7w/8kDrJp+cg+MD9XRArty2LZBLzkgY9fnPS5CiP0FWc6q9HG9HJl6Fpnz9xhvWuSVeucaEz0/gBU9vgnx4y/+3/w9BanHKZpEKL8DO75AXurJ3h82NPqAzbBcXxjcJjc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QRVZBKxl; 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="QRVZBKxl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFDB11F000FF; Wed, 30 Sep 2026 16:50:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790787001; bh=HrUlEQUVTn5PtjyHmDwR9k3TQJOOejGckNKGz8dA0TQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QRVZBKxlKcZM9jb3cF8aFoYSt8szGWogOw/i3zpv1qXYFYW5KaeU92cDy3lSPwKBC 9FGBzz9Lk5E+zqrQZeCxhXcM4/Lv7gEWmuFzsmzTHyBHLGO2ASmMnX4V6LVKRwTk6V kZCaAyzBJ/lQgeoIVr1U3GOsi4PWSX4o8yg+Fw+I= 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 7.2 060/457] s390/cio: Fix cio_update_schib() to not cache invalid schib Date: Wed, 30 Sep 2026 17:22:45 +0200 Message-ID: <20260930152347.334110233@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152346.024115587@linuxfoundation.org> References: <20260930152346.024115587@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 7.2-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 70dc8cc765948..e1c62eb60cca7 100644 --- a/drivers/s390/cio/cio.c +++ b/drivers/s390/cio/cio.c @@ -453,7 +453,8 @@ 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) { @@ -462,10 +463,12 @@ 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