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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 E678EC55ABD for ; Sun, 15 Nov 2020 11:45:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA2D2222C3 for ; Sun, 15 Nov 2020 11:45:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hZoP9Ve4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727031AbgKOLo6 (ORCPT ); Sun, 15 Nov 2020 06:44:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726537AbgKOLo5 (ORCPT ); Sun, 15 Nov 2020 06:44:57 -0500 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75E61C0613D1; Sun, 15 Nov 2020 03:44:57 -0800 (PST) Received: by mail-pj1-x1041.google.com with SMTP id gv24so2499567pjb.3; Sun, 15 Nov 2020 03:44:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=tmv8ZZeN6TdxknLtX/g558yOOygP5SGuU1C7JA+C4O0=; b=hZoP9Ve4d54Ov6C5lzXSlYc/1VBgNVdp0HM83TnmjMByRcWDPDdE/AiipZ+fMHPILu nv0KO1bOr+gZZ63oSB1PKd/0nkFSJvtDqpoJ7r/cKuhYnC9YUhFbzZPU0rJTA75P7aEz ybhTzNaIzW/3OKuUIDH7Kgq7JpcNtx1GRujzZw56OFK+PIRUDWwui0ZHBHALjd0zEjIl FEmhn76n9lCzfYEcsHnZVOY32F9+5SulLnq5RcVFd27I7xg19Zn+dpgh+Mne/ijqgm6l yyWqvSQ6eAsCidyw+QwwSRLdr4ZCDIBRLUn2775/ICR6XdtrJqgxLDhJ+4sIY7wnUmL8 vszQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=tmv8ZZeN6TdxknLtX/g558yOOygP5SGuU1C7JA+C4O0=; b=fFu6QC0JnpzwblZek/MhfL56ov29OfQzwS8dmQPk6R7ByuXZcyKD1aLBDA21y2xl4g in1zUwN+sf4vkRWgR+rrCGwpdk2f22/rk8kCTU5HKaGe+SFuJsV558i9y2iXXHPoVynl CFMqo/fyuyWqfi/udlRcFhHozRiCLEoXBqnhAz+lNZO3WOwEFry3oTOA7zF1gIaIJDnx cE36ctUtyUff/Wsza2THfUDwAEec0hb0+ivV1UTBfNW2sUBDMzYfzyoUHNrTlhxRtkPj lq9cAB5K/DpgrPLekAKpc8Yc2sRHbI+iLvioMEBgtSN/zkkfhycp2OnXaZo3Xkb+6Oqi /MWA== X-Gm-Message-State: AOAM532RT4rFmxASC9dp2lV79JluK8IP9dAnZhLOEY2zED+5UbxAMi62 eFAJAqZUCU/b4yHbfR5TwpM= X-Google-Smtp-Source: ABdhPJzhd5fE9raRSdPzbL7fsH6jo/q3xiNgphqVH6VKQMapA4fU7Ip8o4uMeQJwCzyNBUPR2pDWxw== X-Received: by 2002:a17:90b:1098:: with SMTP id gj24mr11401419pjb.140.1605440696679; Sun, 15 Nov 2020 03:44:56 -0800 (PST) Received: from Thinkpad ([45.118.167.196]) by smtp.gmail.com with ESMTPSA id 21sm15276376pfw.105.2020.11.15.03.44.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Nov 2020 03:44:55 -0800 (PST) Date: Sun, 15 Nov 2020 17:14:48 +0530 From: Anmol Karn To: Jakub Kicinski Cc: ralf@linux-mips.org, davem@davemloft.net, saeed@kernel.org, gregkh@linuxfoundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hams@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, syzkaller-bugs@googlegroups.com, syzbot+a1c743815982d9496393@syzkaller.appspotmail.com Subject: Re: [Linux-kernel-mentees] [PATCH v4 net] rose: Fix Null pointer dereference in rose_send_frame() Message-ID: <20201115114448.GA40574@Thinkpad> References: <20201110194518.GA97719@Thinkpad> <20201111165954.14743-1-anmol.karan123@gmail.com> <20201114111838.03b933af@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201114111838.03b933af@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 14, 2020 at 11:18:38AM -0800, Jakub Kicinski wrote: > On Wed, 11 Nov 2020 22:29:54 +0530 Anmol Karn wrote: > > rose_send_frame() dereferences `neigh->dev` when called from > > rose_transmit_clear_request(), and the first occurrence of the > > `neigh` is in rose_loopback_timer() as `rose_loopback_neigh`, > > and it is initialized in rose_add_loopback_neigh() as NULL. > > i.e when `rose_loopback_neigh` used in rose_loopback_timer() > > its `->dev` was still NULL and rose_loopback_timer() was calling > > rose_rx_call_request() without checking for NULL. > > > > - net/rose/rose_link.c > > This bug seems to get triggered in this line: > > > > rose_call = (ax25_address *)neigh->dev->dev_addr; > > > > Fix it by adding NULL checking for `rose_loopback_neigh->dev` > > in rose_loopback_timer(). > > > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > > Reported-by: syzbot+a1c743815982d9496393@syzkaller.appspotmail.com > > Tested-by: syzbot+a1c743815982d9496393@syzkaller.appspotmail.com > > Link: https://syzkaller.appspot.com/bug?id=9d2a7ca8c7f2e4b682c97578dfa3f236258300b3 > > Signed-off-by: Anmol Karn > > > diff --git a/net/rose/rose_loopback.c b/net/rose/rose_loopback.c > > index 7b094275ea8b..6a71b6947d92 100644 > > --- a/net/rose/rose_loopback.c > > +++ b/net/rose/rose_loopback.c > > @@ -96,10 +96,12 @@ static void rose_loopback_timer(struct timer_list *unused) > > } > > > > if (frametype == ROSE_CALL_REQUEST) { > > - if ((dev = rose_dev_get(dest)) != NULL) { > > + dev = rose_dev_get(dest); > > + if (rose_loopback_neigh->dev && dev) { > > if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) > > kfree_skb(skb); > > } else { > > + dev_put(dev); > > kfree_skb(skb); > > } > > } else { > > This is still not correct. With this code dev_put() could be called with > NULL, which would cause a crash. > > There is also a dev_put() missing if rose_rx_call_request() returns 0. > > I think that this is the correct code: > > diff --git a/net/rose/rose_loopback.c b/net/rose/rose_loopback.c > index 7b094275ea8b..ff252ef73592 100644 > --- a/net/rose/rose_loopback.c > +++ b/net/rose/rose_loopback.c > @@ -96,11 +96,22 @@ static void rose_loopback_timer(struct timer_list *unused) > } > > if (frametype == ROSE_CALL_REQUEST) { > - if ((dev = rose_dev_get(dest)) != NULL) { > - if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) > - kfree_skb(skb); > - } else { > + if (!rose_loopback_neigh->dev) { > kfree_skb(skb); > + continue; > + } > + > + dev = rose_dev_get(dest); > + if (!dev) { > + kfree_skb(skb); > + continue; > + } > + > + if (rose_rx_call_request(skb, dev, rose_loopback_neigh, > + lci_o) == 0) { > + dev_put(dev); > + kfree_skb(skb); > } > } else { > kfree_skb(skb); > > Please test this and resubmit it if it works. Sure sir, I will test it and resend, if it works. Thanks, Anmol 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=-9.3 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 65E5AC2D0E4 for ; Sun, 15 Nov 2020 11:45:01 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 DA1002225B for ; Sun, 15 Nov 2020 11:45:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hZoP9Ve4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DA1002225B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-kernel-mentees-bounces@lists.linuxfoundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 882B2869DA; Sun, 15 Nov 2020 11:45:00 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id HYHpYCYUrOWV; Sun, 15 Nov 2020 11:44:59 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 167A4869CD; Sun, 15 Nov 2020 11:44:59 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 04E07C0800; Sun, 15 Nov 2020 11:44:59 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 448EBC07FF for ; Sun, 15 Nov 2020 11:44:58 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 2104020397 for ; Sun, 15 Nov 2020 11:44:58 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pTBp-YIl7JBd for ; Sun, 15 Nov 2020 11:44:57 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-pj1-f65.google.com (mail-pj1-f65.google.com [209.85.216.65]) by silver.osuosl.org (Postfix) with ESMTPS id 5725520134 for ; Sun, 15 Nov 2020 11:44:57 +0000 (UTC) Received: by mail-pj1-f65.google.com with SMTP id w7so2500138pjy.1 for ; Sun, 15 Nov 2020 03:44:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=tmv8ZZeN6TdxknLtX/g558yOOygP5SGuU1C7JA+C4O0=; b=hZoP9Ve4d54Ov6C5lzXSlYc/1VBgNVdp0HM83TnmjMByRcWDPDdE/AiipZ+fMHPILu nv0KO1bOr+gZZ63oSB1PKd/0nkFSJvtDqpoJ7r/cKuhYnC9YUhFbzZPU0rJTA75P7aEz ybhTzNaIzW/3OKuUIDH7Kgq7JpcNtx1GRujzZw56OFK+PIRUDWwui0ZHBHALjd0zEjIl FEmhn76n9lCzfYEcsHnZVOY32F9+5SulLnq5RcVFd27I7xg19Zn+dpgh+Mne/ijqgm6l yyWqvSQ6eAsCidyw+QwwSRLdr4ZCDIBRLUn2775/ICR6XdtrJqgxLDhJ+4sIY7wnUmL8 vszQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=tmv8ZZeN6TdxknLtX/g558yOOygP5SGuU1C7JA+C4O0=; b=qamglVf4pzvn4WNA01Rf1G9YUUmRubO3n6wHmHvWFYmT3MFn/ROoy2kVIC7nN77wkK 919yduZUSPLDkm4TRmkY5PtpsYNv3VjTC/vLhDMOkQQnAk0+78HC7RUU1krF0GtGQoCS mjOf/gZaC4Rgd6oy3IjYg2NUiGELP7CBp+ugu/ZHYbgjtlW4m8SQ20EPmCHzok3GjtMB +NbSnLclZBys7O5vaKDDfMOKsIIb2G2U9g6XONHMMvqhxtKqFdAxmOQTuadwZ3bVNll7 s149wVXHsbrfy9hJADPVC0p9vWWyqPMdILxlf+r03KKMWU0VI2Vkfo04SFUicW4slG9z kAFQ== X-Gm-Message-State: AOAM531mPJHEKoPdR11dYvt2WwbP8T9IRjDWKJkvMvfwlDEpZWjtm/r0 k5kpICrBjoFpWViszlQ4ayA= X-Google-Smtp-Source: ABdhPJzhd5fE9raRSdPzbL7fsH6jo/q3xiNgphqVH6VKQMapA4fU7Ip8o4uMeQJwCzyNBUPR2pDWxw== X-Received: by 2002:a17:90b:1098:: with SMTP id gj24mr11401419pjb.140.1605440696679; Sun, 15 Nov 2020 03:44:56 -0800 (PST) Received: from Thinkpad ([45.118.167.196]) by smtp.gmail.com with ESMTPSA id 21sm15276376pfw.105.2020.11.15.03.44.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Nov 2020 03:44:55 -0800 (PST) Date: Sun, 15 Nov 2020 17:14:48 +0530 From: Anmol Karn To: Jakub Kicinski Message-ID: <20201115114448.GA40574@Thinkpad> References: <20201110194518.GA97719@Thinkpad> <20201111165954.14743-1-anmol.karan123@gmail.com> <20201114111838.03b933af@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201114111838.03b933af@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Cc: netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org, ralf@linux-mips.org, saeed@kernel.org, syzbot+a1c743815982d9496393@syzkaller.appspotmail.com, linux-hams@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, davem@davemloft.net Subject: Re: [Linux-kernel-mentees] [PATCH v4 net] rose: Fix Null pointer dereference in rose_send_frame() X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" On Sat, Nov 14, 2020 at 11:18:38AM -0800, Jakub Kicinski wrote: > On Wed, 11 Nov 2020 22:29:54 +0530 Anmol Karn wrote: > > rose_send_frame() dereferences `neigh->dev` when called from > > rose_transmit_clear_request(), and the first occurrence of the > > `neigh` is in rose_loopback_timer() as `rose_loopback_neigh`, > > and it is initialized in rose_add_loopback_neigh() as NULL. > > i.e when `rose_loopback_neigh` used in rose_loopback_timer() > > its `->dev` was still NULL and rose_loopback_timer() was calling > > rose_rx_call_request() without checking for NULL. > > > > - net/rose/rose_link.c > > This bug seems to get triggered in this line: > > > > rose_call = (ax25_address *)neigh->dev->dev_addr; > > > > Fix it by adding NULL checking for `rose_loopback_neigh->dev` > > in rose_loopback_timer(). > > > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > > Reported-by: syzbot+a1c743815982d9496393@syzkaller.appspotmail.com > > Tested-by: syzbot+a1c743815982d9496393@syzkaller.appspotmail.com > > Link: https://syzkaller.appspot.com/bug?id=9d2a7ca8c7f2e4b682c97578dfa3f236258300b3 > > Signed-off-by: Anmol Karn > > > diff --git a/net/rose/rose_loopback.c b/net/rose/rose_loopback.c > > index 7b094275ea8b..6a71b6947d92 100644 > > --- a/net/rose/rose_loopback.c > > +++ b/net/rose/rose_loopback.c > > @@ -96,10 +96,12 @@ static void rose_loopback_timer(struct timer_list *unused) > > } > > > > if (frametype == ROSE_CALL_REQUEST) { > > - if ((dev = rose_dev_get(dest)) != NULL) { > > + dev = rose_dev_get(dest); > > + if (rose_loopback_neigh->dev && dev) { > > if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) > > kfree_skb(skb); > > } else { > > + dev_put(dev); > > kfree_skb(skb); > > } > > } else { > > This is still not correct. With this code dev_put() could be called with > NULL, which would cause a crash. > > There is also a dev_put() missing if rose_rx_call_request() returns 0. > > I think that this is the correct code: > > diff --git a/net/rose/rose_loopback.c b/net/rose/rose_loopback.c > index 7b094275ea8b..ff252ef73592 100644 > --- a/net/rose/rose_loopback.c > +++ b/net/rose/rose_loopback.c > @@ -96,11 +96,22 @@ static void rose_loopback_timer(struct timer_list *unused) > } > > if (frametype == ROSE_CALL_REQUEST) { > - if ((dev = rose_dev_get(dest)) != NULL) { > - if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) > - kfree_skb(skb); > - } else { > + if (!rose_loopback_neigh->dev) { > kfree_skb(skb); > + continue; > + } > + > + dev = rose_dev_get(dest); > + if (!dev) { > + kfree_skb(skb); > + continue; > + } > + > + if (rose_rx_call_request(skb, dev, rose_loopback_neigh, > + lci_o) == 0) { > + dev_put(dev); > + kfree_skb(skb); > } > } else { > kfree_skb(skb); > > Please test this and resubmit it if it works. Sure sir, I will test it and resend, if it works. Thanks, Anmol _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees