From patchwork Tue Dec 19 18:09:07 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Engelhardt X-Patchwork-Id: 10123867 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1105A6019C for ; Tue, 19 Dec 2017 18:09:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ED40B294C3 for ; Tue, 19 Dec 2017 18:09:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E1FB1294E3; Tue, 19 Dec 2017 18:09:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 28FF6294C3 for ; Tue, 19 Dec 2017 18:09:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751892AbdLSSJK (ORCPT ); Tue, 19 Dec 2017 13:09:10 -0500 Received: from a3.inai.de ([88.198.180.161]:39830 "EHLO a3.inai.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751875AbdLSSJJ (ORCPT ); Tue, 19 Dec 2017 13:09:09 -0500 Received: by a3.inai.de (Postfix, from userid 25121) id 0BFD41925AA66; Tue, 19 Dec 2017 19:09:07 +0100 (CET) From: Jan Engelhardt To: davem@davemloft.net Cc: sparclinux@vger.kernel.org, jengelh@inai.de, linux-crypto@vger.kernel.org, rmk+kernel@arm.linux.org.uk Subject: [PATCH] crypto: n2 - cure use after free Date: Tue, 19 Dec 2017 19:09:07 +0100 Message-Id: <20171219180907.12895-1-jengelh@inai.de> X-Mailer: git-send-email 2.12.3 In-Reply-To: <20171219.113820.1629794046915223777.davem@davemloft.net> References: <20171219.113820.1629794046915223777.davem@davemloft.net> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP queue_cache_init is first called for the Control Word Queue (n2_crypto_probe). At that time, queue_cache[0] is NULL and a new kmem_cache will be allocated. If the subsequent n2_register_algs call fails, the kmem_cache will be released in queue_cache_destroy, but queue_cache_init[0] is not set back to NULL. So when the Module Arithmetic Unit gets probed next (n2_mau_probe), queue_cache_init will not allocate a kmem_cache again, but leave it as its bogus value, causing a BUG() to trigger when queue_cache[0] is eventually passed to kmem_cache_zalloc: n2_crypto: Found N2CP at /virtual-devices@100/n2cp@7 n2_crypto: Registered NCS HVAPI version 2.0 called queue_cache_init n2_crypto: md5 alg registration failed n2cp f028687c: /virtual-devices@100/n2cp@7: Unable to register algorithms. called queue_cache_destroy n2cp: probe of f028687c failed with error -22 n2_crypto: Found NCP at /virtual-devices@100/ncp@6 n2_crypto: Registered NCS HVAPI version 2.0 called queue_cache_init kernel BUG at mm/slab.c:2993! Call Trace: [0000000000604488] kmem_cache_alloc+0x1a8/0x1e0 (inlined) kmem_cache_zalloc (inlined) new_queue (inlined) spu_queue_setup (inlined) handle_exec_unit [0000000010c61eb4] spu_mdesc_scan+0x1f4/0x460 [n2_crypto] [0000000010c62b80] n2_mau_probe+0x100/0x220 [n2_crypto] [000000000084b174] platform_drv_probe+0x34/0xc0 Signed-off-by: Jan Engelhardt Acked-by: David S. Miller --- drivers/crypto/n2_core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/crypto/n2_core.c b/drivers/crypto/n2_core.c index 48de52cf2ecc..662e709812cc 100644 --- a/drivers/crypto/n2_core.c +++ b/drivers/crypto/n2_core.c @@ -1625,6 +1625,7 @@ static int queue_cache_init(void) CWQ_ENTRY_SIZE, 0, NULL); if (!queue_cache[HV_NCS_QTYPE_CWQ - 1]) { kmem_cache_destroy(queue_cache[HV_NCS_QTYPE_MAU - 1]); + queue_cache[HV_NCS_QTYPE_MAU - 1] = NULL; return -ENOMEM; } return 0; @@ -1634,6 +1635,8 @@ static void queue_cache_destroy(void) { kmem_cache_destroy(queue_cache[HV_NCS_QTYPE_MAU - 1]); kmem_cache_destroy(queue_cache[HV_NCS_QTYPE_CWQ - 1]); + queue_cache[HV_NCS_QTYPE_MAU - 1] = NULL; + queue_cache[HV_NCS_QTYPE_CWQ - 1] = NULL; } static long spu_queue_register_workfn(void *arg)