From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2921FC433C1 for ; Mon, 29 Mar 2021 17:14:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B222561968 for ; Mon, 29 Mar 2021 17:14:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B222561968 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1341B6B007B; Mon, 29 Mar 2021 13:14:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0E45E6B007E; Mon, 29 Mar 2021 13:14:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EEFD66B0080; Mon, 29 Mar 2021 13:14:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0129.hostedemail.com [216.40.44.129]) by kanga.kvack.org (Postfix) with ESMTP id D40956B007B for ; Mon, 29 Mar 2021 13:14:56 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 9A5CE173087A for ; Mon, 29 Mar 2021 17:14:56 +0000 (UTC) X-FDA: 77973561792.29.7EE85C8 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf12.hostedemail.com (Postfix) with ESMTP id 37BD2F9 for ; Mon, 29 Mar 2021 17:14:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=qFjG2sAenIACloeegredFO6bNxng6P7GkaqFjdUrTIE=; b=H1S47WOi3yw9L3md+Wm5LfUZH7 N1hnN7TFFXJorN8+d5wU/uROq47wNZKSkNknrpPBf3MO5HPUU05AbNhEL3StMmAHFCYmDYDNK8PHg PPp3aVFpbtDaEvTiG50hvl1jIYqWgrycuhD4mo/5Zj2NxRozi/PSaBpWSGKqssyy1TE2Iy6rRv1fU Kt1qUPVVo2I7ZSBtpBGm23QQwu1W8fVmNzIbGzw9oSaLl8pIBQoTfRgEQjUqA3g4LLDTO0tIEuqkw I2HSSsjAxgKDHcHeGoHQcP6coJW/TIAHcwSzB5ipRkvK3VDFEj4iTTzhAZ5rP9VXzxnkGn2MAdtMZ uZHlgyCw==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lQvTG-001sAs-Jl; Mon, 29 Mar 2021 17:14:39 +0000 Date: Mon, 29 Mar 2021 18:14:34 +0100 From: Matthew Wilcox To: Colin King Cc: Andrew Morton , Stephen Rothwell , Nicholas Piggin , linux-mm@kvack.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH][next] mm/vmalloc: Fix read of pointer area after it has been free'd Message-ID: <20210329171434.GH351017@casper.infradead.org> References: <20210329170730.121943-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210329170730.121943-1-colin.king@canonical.com> X-Rspamd-Queue-Id: 37BD2F9 X-Stat-Signature: njwqj3gbxpnwjfn3s7a4zo5gtcipy8d1 X-Rspamd-Server: rspam02 Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf12; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617038086-419101 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: On Mon, Mar 29, 2021 at 06:07:30PM +0100, Colin King wrote: > From: Colin Ian King > > Currently the memory pointed to by area is being freed by the > free_vm_area call and then area->nr_pages is referencing the > free'd object. Fix this swapping the order of the warn_alloc > message and the free. > > Addresses-Coverity: ("Read from pointer after free") > Fixes: 014ccf9b888d ("mm/vmalloc: improve allocation failure error messages") i don't have this git sha. if this is -next, the sha ids aren't stable and shouldn't be referenced in commit logs, because these fixes should just be squashed into the not-yet-upstream commits. > Signed-off-by: Colin Ian King > --- > mm/vmalloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index b73e4e715e0d..7936405749e4 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2790,11 +2790,11 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > } > > if (!pages) { > - free_vm_area(area); > warn_alloc(gfp_mask, NULL, > "vmalloc size %lu allocation failure: " > "page array size %lu allocation failed", > area->nr_pages * PAGE_SIZE, array_size); > + free_vm_area(area); > return NULL; this fix looks right to me.