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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C04E1C47404 for ; Fri, 4 Oct 2019 14:48:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F35B20659 for ; Fri, 4 Oct 2019 14:48:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389444AbfJDOsp (ORCPT ); Fri, 4 Oct 2019 10:48:45 -0400 Received: from foss.arm.com ([217.140.110.172]:47296 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388870AbfJDOsp (ORCPT ); Fri, 4 Oct 2019 10:48:45 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EDE8F1597; Fri, 4 Oct 2019 07:48:44 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 779DC3F68E; Fri, 4 Oct 2019 07:48:43 -0700 (PDT) Date: Fri, 4 Oct 2019 15:48:41 +0100 From: Catalin Marinas To: Eric Biggers Cc: Andrew Morton , linux-mm@kvack.org, linux-sctp@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Kent Overstreet , Vlad Yasevich , Xin Long , Neil Horman , Marcelo Ricardo Leitner Subject: Re: [PATCH] lib/generic-radix-tree.c: add kmemleak annotations Message-ID: <20191004144841.GI638@arrakis.emea.arm.com> References: <20191004065039.727564-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191004065039.727564-1-ebiggers@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 03, 2019 at 11:50:39PM -0700, Eric Biggers wrote: > From: Eric Biggers > > Kmemleak is falsely reporting a leak of the slab allocation in > sctp_stream_init_ext(): > > BUG: memory leak > unreferenced object 0xffff8881114f5d80 (size 96): > comm "syz-executor934", pid 7160, jiffies 4294993058 (age 31.950s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<00000000ce7a1326>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] > [<00000000ce7a1326>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<00000000ce7a1326>] slab_alloc mm/slab.c:3326 [inline] > [<00000000ce7a1326>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<000000007abb7ac9>] kmalloc include/linux/slab.h:547 [inline] > [<000000007abb7ac9>] kzalloc include/linux/slab.h:742 [inline] > [<000000007abb7ac9>] sctp_stream_init_ext+0x2b/0xa0 net/sctp/stream.c:157 > [<0000000048ecb9c1>] sctp_sendmsg_to_asoc+0x946/0xa00 net/sctp/socket.c:1882 > [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102 > [...] > > But it's freed later. Kmemleak misses the allocation because its > pointer is stored in the generic radix tree sctp_stream::out, and the > generic radix tree uses raw pages which aren't tracked by kmemleak. > > Fix this by adding the kmemleak hooks to the generic radix tree code. > > Reported-by: syzbot+7f3b6b106be8dcdcdeec@syzkaller.appspotmail.com > Signed-off-by: Eric Biggers Reviewed-by: Catalin Marinas