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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 083B2C433EF for ; Wed, 18 May 2022 12:48:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236566AbiERMsE (ORCPT ); Wed, 18 May 2022 08:48:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238273AbiERMrC (ORCPT ); Wed, 18 May 2022 08:47:02 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6B3BE1BB114 for ; Wed, 18 May 2022 05:45:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652877815; 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=UYuTXRT1KWoD9ySxSkLnG1NBBugOSznwSwCOE9KRgWE=; b=d8kQ0lHVpQdZoh6MRTCLppcZ2QMEkR4DYnt74arPtqNjUk7S6aLRp8FT/FqZJf/b2DERXX Mb6nk9TKuukNNLEVctkX8VyNUYaPoPSgKI1wsNL7zNOIBBbZwKHfDOtwpRtMhNRud6N4VK T9msAk7vrVD4oiH9C8ZulzeAE9vKOgc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-117-JXMIlMU3PFCxSYC2H94bjA-1; Wed, 18 May 2022 08:43:30 -0400 X-MC-Unique: JXMIlMU3PFCxSYC2H94bjA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 17301899EC4; Wed, 18 May 2022 12:43:30 +0000 (UTC) Received: from samus.usersys.redhat.com (unknown [10.43.17.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A6BA91410DD5; Wed, 18 May 2022 12:43:28 +0000 (UTC) Date: Wed, 18 May 2022 14:43:26 +0200 From: Artem Savkov To: Jakub Kicinski Cc: davem@davemloft.net, pabeni@redhat.com, netdev@vger.kernel.org, borisp@nvidia.com, john.fastabend@gmail.com, daniel@iogearbox.net, vfedorenko@novek.ru Subject: Re: [PATCH net-next 10/11] tls: rx: clear ctx->recv_pkt earlier Message-ID: References: <20220408183134.1054551-1-kuba@kernel.org> <20220408183134.1054551-11-kuba@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220408183134.1054551-11-kuba@kernel.org> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, On Fri, Apr 08, 2022 at 11:31:33AM -0700, Jakub Kicinski wrote: > Whatever we do in the loop the skb should not remain on as > ctx->recv_pkt afterwards. We can clear that pointer and > restart strparser earlier. > > This adds overhead of extra linking and unlinking to rx_list > but that's not large (upcoming change will switch to unlocked > skb list operations). > > Signed-off-by: Jakub Kicinski > --- > net/tls/tls_sw.c | 16 +++++++--------- > 1 file changed, 7 insertions(+), 9 deletions(-) > > diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c > index 3aa8fe1c6e77..71d8082647c8 100644 > --- a/net/tls/tls_sw.c > +++ b/net/tls/tls_sw.c > @@ -1826,6 +1826,10 @@ int tls_sw_recvmsg(struct sock *sk, > if (err <= 0) > goto recv_end; > > + ctx->recv_pkt = NULL; > + __strp_unpause(&ctx->strp); > + skb_queue_tail(&ctx->rx_list, skb); > + > if (async) { > /* TLS 1.2-only, to_decrypt must be text length */ > chunk = min_t(int, to_decrypt, len); > @@ -1840,10 +1844,9 @@ int tls_sw_recvmsg(struct sock *sk, > if (err != __SK_PASS) { > rxm->offset = rxm->offset + rxm->full_len; > rxm->full_len = 0; > + skb_unlink(skb, &ctx->rx_list); I have found this patch to be breaking __SK_REDIRECT case as queuing the skb onto psock_other->ingress_skb while already having it in rx_list breaks the latter (at least) ultimately resulting in a null pointer dereference in __skb_queue_purge() during tls_sw_release_resources_rx. This is easily reproducible with selftests/bpf/test_sockmap [ 4363.845728][ T370] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 4363.851749][ T370] #PF: supervisor write access in kernel mode [ 4363.856364][ T370] #PF: error_code(0x0002) - not-present page [ 4363.862678][ T370] PGD 0 P4D 0 [ 4363.866893][ T370] Oops: 0002 [#1] PREEMPT SMP PTI [ 4363.871576][ T370] CPU: 1 PID: 370 Comm: test_sockmap Not tainted 5.18.0-rc3.bpf-00792-g98a90feedc4e-dirty #649 22ffa66a3068b39367ed1f9d77b2a5bb8f7921a2 [ 4363.882164][ T370] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014 [ 4363.890561][ T370] RIP: 0010:tls_sw_release_resources_rx+0xac/0x120 [ 4363.895582][ T370] Code: 00 48 89 ef be 01 00 00 00 83 e8 01 89 83 e8 01 00 00 48 8b 55 00 48 8b 45 08 48 c7 45 00 00 00 00 00 48 c7 45 08 00 00 00 00 <48> 89 42 08 48 89 10 e8 48 ed d4 ff 48 8b ab d8 01 00 00 49 39 ec [ 4363.912545][ T370] RSP: 0018:ffffc90000cabb98 EFLAGS: 00010297 [ 4363.917672][ T370] RAX: 0000000000000000 RBX: ffff888113e10c00 RCX: 0000000000000000 [ 4363.922860][ T370] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888100810400 [ 4363.929092][ T370] RBP: ffff888100810400 R08: 0000000000000040 R09: ffff8881099bc740 [ 4363.935344][ T370] R10: 0000000000000001 R11: ffff8881099cebc8 R12: ffff888113e10dd8 [ 4363.940657][ T370] R13: ffff88810759c500 R14: ffff88810759c8a0 R15: 0000000000000001 [ 4363.944835][ T370] FS: 0000000000000000(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000 [ 4363.948247][ T370] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4363.949967][ T370] CR2: 0000000000000008 CR3: 0000000003e72005 CR4: 0000000000170ea0 [ 4363.952346][ T370] Call Trace: [ 4363.953458][ T370] [ 4363.954472][ T370] tls_sk_proto_close+0x29e/0x3b0 [ 4363.956060][ T370] ? __sock_release+0xf0/0xf0 [ 4363.957432][ T370] inet_release+0x63/0xb0 [ 4363.958857][ T370] __sock_release+0x56/0xf0 [ 4363.960319][ T370] sock_close+0x1d/0x30 [ 4363.961668][ T370] __fput+0xd3/0x360 [ 4363.962969][ T370] task_work_run+0x7b/0xc0 [ 4363.964415][ T370] do_exit+0x25f/0x610 [ 4363.965577][ T370] do_group_exit+0x44/0xe0 [ 4363.966802][ T370] get_signal+0xa48/0xa60 [ 4363.967993][ T370] arch_do_signal_or_restart+0x25/0x100 [ 4363.969706][ T370] ? lockdep_hardirqs_on+0xbf/0x130 [ 4363.971241][ T370] exit_to_user_mode_prepare+0x123/0x190 [ 4363.972904][ T370] syscall_exit_to_user_mode+0x19/0x50 [ 4363.974630][ T370] do_syscall_64+0x69/0x80 [ 4363.976075][ T370] ? do_syscall_64+0x69/0x80 [ 4363.977562][ T370] ? lockdep_hardirqs_on+0xbf/0x130 [ 4363.979998][ T370] ? do_syscall_64+0x69/0x80 [ 4363.981466][ T370] ? syscall_exit_to_user_mode+0x1e/0x50 [ 4363.983414][ T370] ? do_syscall_64+0x69/0x80 [ 4363.984805][ T370] ? lockdep_hardirqs_on+0xbf/0x130 [ 4363.986498][ T370] ? do_syscall_64+0x69/0x80 [ 4363.988110][ T370] ? exc_page_fault+0xbd/0x170 [ 4363.989749][ T370] ? asm_exc_page_fault+0x8/0x30 [ 4363.991203][ T370] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 4363.993175][ T370] RIP: 0033:0x7ffff7e45a26 [ 4363.994479][ T370] Code: Unable to access opcode bytes at RIP 0x7ffff7e459fc. [ 4363.996791][ T370] RSP: 002b:00007fffffffe0f8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d [ 4363.999448][ T370] RAX: fffffffffffffe00 RBX: 000000000045c720 RCX: 00007ffff7e45a26 [ 4364.001904][ T370] RDX: 0000000000000000 RSI: 00007fffffffe11c RDI: 0000000000000238 [ 4364.004265][ T370] RBP: 00007fffffffe180 R08: 0000000000000000 R09: 00007ffff7f0d0c0 [ 4364.006574][ T370] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000040a970 [ 4364.009478][ T370] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 4364.011687][ T370] [ 4364.012530][ T370] Modules linked in: [ 4364.013470][ T370] CR2: 0000000000000008 [ 4364.014658][ T370] ---[ end trace 0000000000000000 ]--- > if (err == __SK_DROP) > consume_skb(skb); > - ctx->recv_pkt = NULL; > - __strp_unpause(&ctx->strp); > continue; > } > } > @@ -1869,14 +1872,9 @@ int tls_sw_recvmsg(struct sock *sk, > len -= chunk; > > /* For async or peek case, queue the current skb */ > - if (async || is_peek || retain_skb) { > - skb_queue_tail(&ctx->rx_list, skb); > - ctx->recv_pkt = NULL; > - __strp_unpause(&ctx->strp); > - } else { > + if (!(async || is_peek || retain_skb)) { > + skb_unlink(skb, &ctx->rx_list); > consume_skb(skb); > - ctx->recv_pkt = NULL; > - __strp_unpause(&ctx->strp); > > /* Return full control message to > * userspace before trying to parse > -- > 2.34.1 > -- Artem