From patchwork Wed Mar 30 14:22:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 12795871 X-Patchwork-Delegate: kuba@kernel.org 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 90FB7C433EF for ; Wed, 30 Mar 2022 14:22:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346762AbiC3OYO (ORCPT ); Wed, 30 Mar 2022 10:24:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346758AbiC3OYM (ORCPT ); Wed, 30 Mar 2022 10:24:12 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E4C1920594A for ; Wed, 30 Mar 2022 07:22:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1648650144; 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: content-transfer-encoding:content-transfer-encoding; bh=V8lwe1nJ277ErLzO2JvOAl8qLHlH5LlGzwKHRcvdCBU=; b=aBP1RazWPdzzHAztzePZ1V1geEEmSJgZ3FIxoN16uR6LW5SVOYNBxvuIWxE8LR9pDY9asd U9ZY4jypCkCddOnGQwg1/ZcQMmGcjapTg+P7VtvKmFrTIWjXj9Bzq6/I/+zcGqvezay+PO iSF28+cr7Owh3MSqEuQMHJ5zDPxyu4E= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-100-5Y00R3zkPfq4RQIRR8_cwg-1; Wed, 30 Mar 2022 10:22:21 -0400 X-MC-Unique: 5Y00R3zkPfq4RQIRR8_cwg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 919DA381749F; Wed, 30 Mar 2022 14:22:20 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 77553C1D38B; Wed, 30 Mar 2022 14:22:17 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH net] rxrpc: fix some null-ptr-deref bugs in server_key.c From: David Howells To: netdev@vger.kernel.org Cc: Xiaolong Huang , Xiaolong Huang , Marc Dionne , linux-afs@lists.infradead.org, dhowells@redhat.com, linux-kernel@vger.kernel.org Date: Wed, 30 Mar 2022 15:22:14 +0100 Message-ID: <164865013439.2941502.8966285221215590921.stgit@warthog.procyon.org.uk> User-Agent: StGit/1.4 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Xiaolong Huang Some function calls are not implemented in rxrpc_no_security, there are preparse_server_key, free_preparse_server_key and destroy_server_key. When rxrpc security type is rxrpc_no_security, user can easily trigger a null-ptr-deref bug via ioctl. So judgment should be added to prevent it The crash log: user@syzkaller:~$ ./rxrpc_preparse_s [ 37.956878][T15626] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 37.957645][T15626] #PF: supervisor instruction fetch in kernel mode [ 37.958229][T15626] #PF: error_code(0x0010) - not-present page [ 37.958762][T15626] PGD 4aadf067 P4D 4aadf067 PUD 4aade067 PMD 0 [ 37.959321][T15626] Oops: 0010 [#1] PREEMPT SMP [ 37.959739][T15626] CPU: 0 PID: 15626 Comm: rxrpc_preparse_ Not tainted 5.17.0-01442-gb47d5a4f6b8d #43 [ 37.960588][T15626] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014 [ 37.961474][T15626] RIP: 0010:0x0 [ 37.961787][T15626] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [ 37.962480][T15626] RSP: 0018:ffffc9000d9abdc0 EFLAGS: 00010286 [ 37.963018][T15626] RAX: ffffffff84335200 RBX: ffff888012a1ce80 RCX: 0000000000000000 [ 37.963727][T15626] RDX: 0000000000000000 RSI: ffffffff84a736dc RDI: ffffc9000d9abe48 [ 37.964425][T15626] RBP: ffffc9000d9abe48 R08: 0000000000000000 R09: 0000000000000002 [ 37.965118][T15626] R10: 000000000000000a R11: f000000000000000 R12: ffff888013145680 [ 37.965836][T15626] R13: 0000000000000000 R14: ffffffffffffffec R15: ffff8880432aba80 [ 37.966441][T15626] FS: 00007f2177907700(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000 [ 37.966979][T15626] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 37.967384][T15626] CR2: ffffffffffffffd6 CR3: 000000004aaf1000 CR4: 00000000000006f0 [ 37.967864][T15626] Call Trace: [ 37.968062][T15626] [ 37.968240][T15626] rxrpc_preparse_s+0x59/0x90 [ 37.968541][T15626] key_create_or_update+0x174/0x510 [ 37.968863][T15626] __x64_sys_add_key+0x139/0x1d0 [ 37.969165][T15626] do_syscall_64+0x35/0xb0 [ 37.969451][T15626] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 37.969824][T15626] RIP: 0033:0x43a1f9 Signed-off-by: Xiaolong Huang Tested-by: Xiaolong Huang Signed-off-by: David Howells Acked-by: Marc Dionne cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2022-March/005069.html --- net/rxrpc/server_key.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/rxrpc/server_key.c b/net/rxrpc/server_key.c index ead3471307ee..ee269e0e6ee8 100644 --- a/net/rxrpc/server_key.c +++ b/net/rxrpc/server_key.c @@ -84,6 +84,9 @@ static int rxrpc_preparse_s(struct key_preparsed_payload *prep) prep->payload.data[1] = (struct rxrpc_security *)sec; + if (!sec->preparse_server_key) + return -EINVAL; + return sec->preparse_server_key(prep); } @@ -91,7 +94,7 @@ static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep) { const struct rxrpc_security *sec = prep->payload.data[1]; - if (sec) + if (sec && sec->free_preparse_server_key) sec->free_preparse_server_key(prep); } @@ -99,7 +102,7 @@ static void rxrpc_destroy_s(struct key *key) { const struct rxrpc_security *sec = key->payload.data[1]; - if (sec) + if (sec && sec->destroy_server_key) sec->destroy_server_key(key); }