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=-3.8 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 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 688A9C433E0 for ; Tue, 16 Feb 2021 17:52:48 +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 0E0EA64E04 for ; Tue, 16 Feb 2021 17:52:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E0EA64E04 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=zx2c4.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:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+Ndcz5k7PigBzmxpdXV67zzteiFEvrGOQYA5PcmpYXo=; b=cUuENkLnMp9QCwsJqzFgYZLVZ RTZ+Ohj/smf8vppgZAZ2dMpXP2M4vpxPXWldBCCXZLJNXF/qlPQJ/TQbOZvuKFqQAVFebY7ui9CkG zb5oFk/Ep+Vd+jgzZ9HZmtJl48gHkUXL36jDxIF+I5vtuGGW9J2jPyqOIrD0m1oi2PvRMVumKSKuJ oFvPUhaXtLOlCBkA5DzOWcBUQWTXXV2RZjMSn6O0o1SmoIAyzs/g/WBNkWUVwzC+dS9V3Ntwy1dCJ hFGn3P8rsAJBn0WXeX2sg42I6O3hgXgXfm1pRV5cLFLFnfV4q4wnySFyn2XG8kbqObOpIAK5Wp5lX 806baZRZQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lC4Uf-000312-DQ; Tue, 16 Feb 2021 17:50:37 +0000 Received: from mail.zx2c4.com ([104.131.123.232]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lC4Uc-00030b-Eu for linux-arm-kernel@lists.infradead.org; Tue, 16 Feb 2021 17:50:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1613497832; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=x6vLcN+xqMivEhRJClR/OiRKsu8E4NuYns8fLQSOv1Q=; b=XSd24Z36dyguJIhuYmlHtrumRpIqSyube+ePKhS94bbrycLZSLS/oO1xt/ajCZ6TDSlMnU idpOeGvX7pZQQNyb+NgpYjwfzvtYlIljIb+Noy2b8AU6WxPfQLa7JSmbgt+K8k2gcDpSAw Q5n96xcd5w6uVbC4svIBFEyy+H4dSZo= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 5b2c6c23 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO) for ; Tue, 16 Feb 2021 17:50:32 +0000 (UTC) Received: by mail-yb1-f173.google.com with SMTP id m188so11195100yba.13 for ; Tue, 16 Feb 2021 09:50:32 -0800 (PST) X-Gm-Message-State: AOAM533lgZIiu0ky987dkaWuu0uuzTq/qacsqyJ8tMjyYpplY+I7yS6E mUL/o/QYLtbAi9xdffNe7xhYjOIy1P4WGE6WA+0= X-Google-Smtp-Source: ABdhPJwHt58xFP7YNMEve7qalwe99uM3eNJOjQyTF4f4AMRjItfs/mCB7J7f54GmIkOIxJqYe9dl3LeVEr9k0RC2Z58= X-Received: by 2002:a25:b74c:: with SMTP id e12mr34153553ybm.20.1613497831569; Tue, 16 Feb 2021 09:50:31 -0800 (PST) MIME-Version: 1.0 References: <0000000000000be4d705bb68dfa7@google.com> <20210216172817.GA14978@arm.com> In-Reply-To: From: "Jason A. Donenfeld" Date: Tue, 16 Feb 2021 18:50:20 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: KASAN: invalid-access Write in enqueue_timer To: Netdev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210216_125034_554333_6CFA12E9 X-CRM114-Status: GOOD ( 20.88 ) 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 , Catalin Marinas , 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 6:46 PM Jason A. Donenfeld wrote: > > Hi Catalin, > > On Tue, Feb 16, 2021 at 6:28 PM Catalin Marinas wrote: > > Adding Jason and Ard. It may be a use-after-free in the wireguard > > driver. > > Thanks for sending this my way. Note: to my knowledge, Ard doesn't > work on wireguard. > > > > 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? > > The allocation and deallocation backtrace is confusing > > > > alloc_netdev_mqs+0x5c/0x3bc net/core/dev.c:10546 > > > rtnl_create_link+0xc8/0x2b0 net/core/rtnetlink.c:3171 > > > __rtnl_newlink+0x5bc/0x800 net/core/rtnetlink.c:3433 > > This suggests it's part of the `ip link add wg0 type wireguard` nelink > call, during it's allocation of the netdevice's private area. For > this, the wg_device struct is used. It has no timer_list structures in > it! > > Similarly, > > > > netdev_freemem+0x18/0x2c net/core/dev.c:10500 > > > netdev_release+0x30/0x44 net/core/net-sysfs.c:1828 > > > device_release+0x34/0x90 drivers/base/core.c:1980 > > That smells like `ip link del wg0 type wireguard`. But again, > wg_device doesn't have any timer_lists in it. > > So what's happening here exactly? I'm not really sure yet... > > It'd be nice to have a reproducer. > > > Jason 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 And one from ext4: https://syzkaller.appspot.com/text?tag=CrashReport&x=17685330d00000 And from from ext4 with fddup: https://syzkaller.appspot.com/text?tag=CrashReport&x=17685330d00000 https://syzkaller.appspot.com/text?tag=CrashReport&x=12d326e8d00000 It might not actually be a wireguard bug? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel