From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753204AbbICHze (ORCPT ); Thu, 3 Sep 2015 03:55:34 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:43662 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752918AbbICHzb (ORCPT ); Thu, 3 Sep 2015 03:55:31 -0400 X-Helo: d23dlp02.au.ibm.com X-MailFrom: aneesh.kumar@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org From: "Aneesh Kumar K.V" To: akpm@linux-foundation.org, Andrey Ryabinin Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Aneesh Kumar K.V" Subject: [PATCH 3/4] kasan: Don't use kasan shadow pointer in generic functions Date: Thu, 3 Sep 2015 13:24:22 +0530 Message-Id: <1441266863-5435-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1441266863-5435-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1441266863-5435-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15090307-1618-0000-0000-000002B65CC4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We can't use generic functions like print_hex_dump to access kasan shadow region. This require us to setup another kasan shadow region for the address passed (kasan shadow address). Most architecture won't be able to do that. Hence make a copy of the shadow region row and pass that to generic functions. Signed-off-by: Aneesh Kumar K.V --- mm/kasan/report.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 01d2efec8ea4..440bda3a3ecd 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -164,14 +164,20 @@ static void print_shadow_for_address(const void *addr) for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) { const void *kaddr = kasan_shadow_to_mem(shadow_row); char buffer[4 + (BITS_PER_LONG/8)*2]; + char shadow_buf[SHADOW_BYTES_PER_ROW]; snprintf(buffer, sizeof(buffer), (i == 0) ? ">%p: " : " %p: ", kaddr); - + /* + * We should not pass a shadow pointer to generic + * function, because generic functions may try to + * access kasan mapping for the passed address. + */ kasan_disable_current(); + memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW); print_hex_dump(KERN_ERR, buffer, DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1, - shadow_row, SHADOW_BYTES_PER_ROW, 0); + shadow_buf, SHADOW_BYTES_PER_ROW, 0); kasan_enable_current(); if (row_is_guilty(shadow_row, shadow)) -- 2.5.0