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=-5.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 4E134C433DB for ; Tue, 16 Feb 2021 18:03:52 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1774A64DA1 for ; Tue, 16 Feb 2021 18:03:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1774A64DA1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=1ifb3mi5xiFpgPkBCjd5EFhgzQZ0bR2tkazc9BGjSvM=; b=KlF0Qv8UTCjX9xIghlf0I2fbw w/QWnVgxsU4dJLSNTFD5WTwFyFvT5Q6iMfkO3AnKnFBOLNF/5BkN+4c8FB/GAovM38/bZzXGEpW31 8QWkzqbC1nn6rcUqHV5p/MQEWIinnntuaMWmS9FR7Ckk+1WnkEhEYJzyrUsy7tjDWr50OeH0DN0X9 XhF7H7OdyP0WvrDHwL6ze5Zo/FqOXk2RPe53qmIq0BJ5UaUUlB3laxAlBX2pQ69K9xUQfjrlgtBSn gZPWpptwFoRNEgEoQ3PMpHptMZWaTIuhXTGS/hPz11EIR0YpwTHHw4h+CHLZCyCia24HeUEC+E2pA 3zYTIwh0A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lC4fY-0004CW-LE; Tue, 16 Feb 2021 18:01:52 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lC4fV-0004Bm-PI for linux-arm-kernel@lists.infradead.org; Tue, 16 Feb 2021 18:01:50 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id F0EF064DA1; Tue, 16 Feb 2021 18:01:46 +0000 (UTC) Date: Tue, 16 Feb 2021 18:01:44 +0000 From: Catalin Marinas To: "Jason A. Donenfeld" Subject: Re: KASAN: invalid-access Write in enqueue_timer Message-ID: <20210216180143.GB14978@arm.com> References: <0000000000000be4d705bb68dfa7@google.com> <20210216172817.GA14978@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210216_130149_886847_08D5319F X-CRM114-Status: GOOD ( 17.17 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Kees Cook , Netdev , syzkaller-bugs , LKML , Mark Brown , syzbot , mbenes@suse.cz, Will Deacon , Ard Biesheuvel , linux-arm-kernel Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Feb 16, 2021 at 06:50:20PM +0100, Jason A. Donenfeld wrote: > On Tue, Feb 16, 2021 at 6:46 PM Jason A. Donenfeld wrote: > > On Tue, Feb 16, 2021 at 6:28 PM Catalin Marinas wrote: > > > > hlist_add_head include/linux/list.h:883 [inline] > > > > enqueue_timer+0x18/0xc0 kernel/time/timer.c:581 > > > > mod_timer+0x14/0x20 kernel/time/timer.c:1106 > > > > mod_peer_timer drivers/net/wireguard/timers.c:37 [inline] > > > > wg_timers_any_authenticated_packet_traversal+0x68/0x90 drivers/net/wireguard/timers.c:215 > > > > The line of hlist_add_head that it's hitting is: > > > > static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) > > { > > struct hlist_node *first = h->first; > > WRITE_ONCE(n->next, first); > > if (first) > > > > So that means it's the dereferencing of h that's a problem. That comes from: > > > > static void enqueue_timer(struct timer_base *base, struct timer_list *timer, > > unsigned int idx, unsigned long bucket_expiry) > > { > > > > hlist_add_head(&timer->entry, base->vectors + idx); > > > > That means it concerns base->vectors + idx, not the timer_list object > > that wireguard manages. That's confusing. Could that imply that the > > bug is in freeing a previous timer without removing it from the timer > > lists, so that it winds up being in base->vectors? Good point, it's indeed likely that the timer list is messed up already, just an unlucky encounter in the wireguard code. > Digging around on syzkaller, it looks like there's a similar bug on > jbd2, concerning iptunnels's allocation: > > https://syzkaller.appspot.com/text?tag=CrashReport&x=13afb19cd00000 [...] > It might not actually be a wireguard bug? I wonder whether syzbot reported similar issues with CONFIG_KASAN_SW_TAGS. It shouldn't be that different from the HW_TAGS but at least we can rule out qemu bugs with the MTE emulation. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel