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 7FC0B768FC; Sun, 28 Jul 2024 15:51:14 +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=1722181874; cv=none; b=I/Hy4ZUe+BcRde9Z5xVM7DDwgKYcBJjOXrKDBD82luqfriLtxKb/sUeWLJ63aYYv9nnRT2jF0KXuXHzd+maSGp7o9qmAUoVtS5lGUMfcfG7DKaU5dqtDxCbrnEsgXv4HzxZQZGdXngU2QcyVqN6zsRP7vVg1h4JwN9QvuL58i5k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722181874; c=relaxed/simple; bh=MCl2thOrMpSD7UbCXdQ7fzx+9mC48PAXCPYzgWxy9SI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ABeWkbJ/wXzDnsoUc6WhmBQdGu8wPujkdAbWA/nsyQgG/NtEGl9HhRpUtqdSMnLeu4CUKU6iVFx4Ajpd63vMAUbC/dgqDsLNbK8pE4ZNeyWW8R2hdrGm+339k1/ZneMOXgCzTIw07UqEYUUoxSEyosZSKp+88u7J0BdpljG8mxY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QWEm41Qh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QWEm41Qh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E4BFC4AF0A; Sun, 28 Jul 2024 15:51:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722181874; bh=MCl2thOrMpSD7UbCXdQ7fzx+9mC48PAXCPYzgWxy9SI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QWEm41QhEIH8VU44X3dDMvmGaHXgJQ9yNJ9nseqSB8pEayoWKq101qdSh0I5jd60o RbYDMAgAmMTSYHMSpOFV18lJejyTKGLua0OXoG0KknG+zyaXd74lkhwWZd0PEPIK4e 7/od9bvz+sa4plpe3/npsjKGc0AeaIL4U2PCCrEpsJXG1/GT6FS0coQg9pnFEl73Qe hO9ErXpNNK1HpDECdAV3rHVGtLa3pr3CUv6upDzLkrIZ6sjT+N2ZJUs38n1p234qxH VYfdByRh0AioABvzEnolLWqsw940OnjiKtAIcUjkiFja3qZmxwSxJ/M5Ir3nQDXq3q cGe3oUixftVAw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Oberparleiter , Heiko Carstens , Alexander Gordeev , Sasha Levin , gor@linux.ibm.com, linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 4/5] s390/sclp: Prevent release of buffer in I/O Date: Sun, 28 Jul 2024 11:50:59 -0400 Message-ID: <20240728155103.2050728-4-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240728155103.2050728-1-sashal@kernel.org> References: <20240728155103.2050728-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.319 Content-Transfer-Encoding: 8bit From: Peter Oberparleiter [ Upstream commit bf365071ea92b9579d5a272679b74052a5643e35 ] When a task waiting for completion of a Store Data operation is interrupted, an attempt is made to halt this operation. If this attempt fails due to a hardware or firmware problem, there is a chance that the SCLP facility might store data into buffers referenced by the original operation at a later time. Handle this situation by not releasing the referenced data buffers if the halt attempt fails. For current use cases, this might result in a leak of few pages of memory in case of a rare hardware/firmware malfunction. Reviewed-by: Heiko Carstens Signed-off-by: Peter Oberparleiter Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin --- drivers/s390/char/sclp_sd.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/s390/char/sclp_sd.c b/drivers/s390/char/sclp_sd.c index 1e244f78f1929..64581433c3349 100644 --- a/drivers/s390/char/sclp_sd.c +++ b/drivers/s390/char/sclp_sd.c @@ -319,8 +319,14 @@ static int sclp_sd_store_data(struct sclp_sd_data *result, u8 di) &esize); if (rc) { /* Cancel running request if interrupted */ - if (rc == -ERESTARTSYS) - sclp_sd_sync(page, SD_EQ_HALT, di, 0, 0, NULL, NULL); + if (rc == -ERESTARTSYS) { + if (sclp_sd_sync(page, SD_EQ_HALT, di, 0, 0, NULL, NULL)) { + pr_warn("Could not stop Store Data request - leaking at least %zu bytes\n", + (size_t)dsize * PAGE_SIZE); + data = NULL; + asce = 0; + } + } vfree(data); goto out; } -- 2.43.0