From patchwork Fri Oct 1 02:41:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Matthew Wilcox (Oracle)" X-Patchwork-Id: 12529663 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF557C433EF for ; Fri, 1 Oct 2021 02:42:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 26C2F61164 for ; Fri, 1 Oct 2021 02:42:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 26C2F61164 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 9CCD79400F0; Thu, 30 Sep 2021 22:42:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 954059400E4; Thu, 30 Sep 2021 22:42:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7F77B9400F0; Thu, 30 Sep 2021 22:42:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id 66B259400E4 for ; Thu, 30 Sep 2021 22:42:45 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 17EBB1839C017 for ; Fri, 1 Oct 2021 02:42:45 +0000 (UTC) X-FDA: 78646320690.22.54744DD Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf20.hostedemail.com (Postfix) with ESMTP id 8724BD00047A for ; Fri, 1 Oct 2021 02:42:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=9b7Y2D8y+bwLRWgPDl2sed9F2MPffsUsdfPD7nrHpcA=; b=L8hPFr3Z7+3SrGqtbww3txa5GZ u98C5rrfId8pWL+7SmgDI09ZodTyAVpx6TMAYILDJh1EHnsAcjLkMODKSzbqxHktWvEf29HQdtdqQ A/+7uexrV8VjYIo40pIZZymyEPiqx0vLCZCBvNJ0f+1Qwowno2VeD65ofDRzDc2dAFXmu3RFRJHe+ gYrHtAA4lo/LPeNu9qLMqZG6mE6ZaB27LpfwqzLI14oR7QzB/AdHTR3k4OUpnOLzqIGRSQ9C5bZHN wLHAWE1y98zP1ZtFVieZ8QagKjQU9rINydtVJH1DcHEWEClYxlD+q1xtml70cw45RFCjKr4pj/GCO 6ZAtNLbg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mW8U8-00DV2b-6j; Fri, 01 Oct 2021 02:41:37 +0000 From: "Matthew Wilcox (Oracle)" To: Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Andrew Morton , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" Subject: [PATCH] kasan: Fix tag for large allocations when using CONFIG_SLAB Date: Fri, 1 Oct 2021 03:41:05 +0100 Message-Id: <20211001024105.3217339-1-willy@infradead.org> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 8724BD00047A X-Stat-Signature: z8e7wzfwfi77pewce55o4pdeadzso37u Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=L8hPFr3Z; spf=none (imf20.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-HE-Tag: 1633056164-180523 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: If an object is allocated on a tail page of a multi-page slab, kasan will get the wrong tag because page->s_mem is NULL for tail pages. I'm not quite sure what the user-visible effect of this might be. Fixes: 7f94ffbc4c6a ("kasan: add hooks implementation for tag-based mode") Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Marco Elver Reviewed-by: Andrey Konovalov --- mm/kasan/common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 2baf121fb8c5..41779ad109cd 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -298,7 +298,7 @@ static inline u8 assign_tag(struct kmem_cache *cache, /* For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU: */ #ifdef CONFIG_SLAB /* For SLAB assign tags based on the object index in the freelist. */ - return (u8)obj_to_index(cache, virt_to_page(object), (void *)object); + return (u8)obj_to_index(cache, virt_to_head_page(object), (void *)object); #else /* * For SLUB assign a random tag during slab creation, otherwise reuse