From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58524 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728937AbeIXSh1 (ORCPT ); Mon, 24 Sep 2018 14:37:27 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Xiao, Jin" , Mikulas Patocka , Mike Snitzer Subject: [PATCH 4.18 120/235] dm verity: fix crash on bufio buffer that was allocated with vmalloc Date: Mon, 24 Sep 2018 13:51:46 +0200 Message-Id: <20180924113118.142173320@linuxfoundation.org> In-Reply-To: <20180924113103.999624566@linuxfoundation.org> References: <20180924113103.999624566@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit e4b069e0945fa14c71cf8b5b89f8b1b2aa68dbc2 upstream. Since commit d1ac3ff008fb ("dm verity: switch to using asynchronous hash crypto API") dm-verity uses asynchronous crypto calls for verification, so that it can use hardware with asynchronous processing of crypto operations. These asynchronous calls don't support vmalloc memory, but the buffer data can be allocated with vmalloc if dm-bufio is short of memory and uses a reserved buffer that was preallocated in dm_bufio_client_create(). Fix verity_hash_update() so that it deals with vmalloc'd memory correctly. Reported-by: "Xiao, Jin" Signed-off-by: Mikulas Patocka Fixes: d1ac3ff008fb ("dm verity: switch to using asynchronous hash crypto API") Cc: stable@vger.kernel.org # 4.12+ Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-verity-target.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -99,10 +99,26 @@ static int verity_hash_update(struct dm_ { struct scatterlist sg; - sg_init_one(&sg, data, len); - ahash_request_set_crypt(req, &sg, NULL, len); - - return crypto_wait_req(crypto_ahash_update(req), wait); + if (likely(!is_vmalloc_addr(data))) { + sg_init_one(&sg, data, len); + ahash_request_set_crypt(req, &sg, NULL, len); + return crypto_wait_req(crypto_ahash_update(req), wait); + } else { + do { + int r; + size_t this_step = min_t(size_t, len, PAGE_SIZE - offset_in_page(data)); + flush_kernel_vmap_range((void *)data, this_step); + sg_init_table(&sg, 1); + sg_set_page(&sg, vmalloc_to_page(data), this_step, offset_in_page(data)); + ahash_request_set_crypt(req, &sg, NULL, this_step); + r = crypto_wait_req(crypto_ahash_update(req), wait); + if (unlikely(r)) + return r; + data += this_step; + len -= this_step; + } while (len); + return 0; + } } /*