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 7262F823CB; Sun, 28 Jul 2024 15:47:23 +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=1722181643; cv=none; b=mVUAMlCh6C065o1JflddoMTsw9J7esEvBaLeECFfS1y51ysY+WqB2GQNzRwTTGcmG8h0LV46xf7kUlkxgHtxsBxMDGRNhLEyEUmeGSUbbdVxVLRLiUDspXKBGEaYXj4t0F60K9LF1jFCAG0VFJ/Mgtk3r0auzjVbkkJNW+o2V48= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722181643; c=relaxed/simple; bh=fu9IFAHAFSVZXRrNmnKacWWm82vIqE+AmfedSfWIhuU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pMfeeL7oar2JPNg7FjOgLnoPdi/Tmto/ozdMv3E+yHhUa/6lnDYPYvRL9tjcU3HVItxWqQgPSwo61TtRtfAyAz2GDrPQDTTHgDfe8PIZZLak8IDccrkqwsOCVWskQsBZpS+AWXMici1h7zp5h6+IDXNsVi6VbRxsnfZBeLhvFx8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IjNYT85P; 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="IjNYT85P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B75BC116B1; Sun, 28 Jul 2024 15:47:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722181643; bh=fu9IFAHAFSVZXRrNmnKacWWm82vIqE+AmfedSfWIhuU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IjNYT85PEEaMERS9RJLWmsgyM6MX2HYG4t4Ip2VYkA7isxH1cCOggDHufMt9RhvZC hqpCU/MtB2kcv8YNwvUr+VQBnNF7M76Qr1iR4ju9D3YTYmiAFSryisCcyHEHNL95Vl 7Bg1unJ1P/3/eyV+NK0vLdqcBopD1b0pzFBlkC9Ew5kRmxGb08Gd4mLmTYlZcn5s5N wUnwUnbPbWUMhCY0M3fCuobar0HTIZKS4PcVx/4SNSQ5c1L04/1QnBWLggmx8X4w7g dG1flmyOHKsuOh4ZY3aqsPwPkduERKlRiOvHaVmAjgCvSDO+1T8h0UYUUVFjq9G+ph R5ZhIgfWwyDvA== 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 6.6 19/20] s390/sclp: Prevent release of buffer in I/O Date: Sun, 28 Jul 2024 11:45:17 -0400 Message-ID: <20240728154605.2048490-19-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240728154605.2048490-1-sashal@kernel.org> References: <20240728154605.2048490-1-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 6.6.43 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 f9e164be7568f..944e75beb160c 100644 --- a/drivers/s390/char/sclp_sd.c +++ b/drivers/s390/char/sclp_sd.c @@ -320,8 +320,14 @@ 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