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 03D0DC38A2B for ; Tue, 5 Apr 2022 10:17:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353994AbiDEKKV (ORCPT ); Tue, 5 Apr 2022 06:10:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346930AbiDEJYu (ORCPT ); Tue, 5 Apr 2022 05:24:50 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D731A147D; Tue, 5 Apr 2022 02:14:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 45459B81C19; Tue, 5 Apr 2022 09:14:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4E8CC385A9; Tue, 5 Apr 2022 09:14:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649150044; bh=UO2eg/kU3zQNVWeY1pHzVEaHjxnStJIMnFDNAI8p7yE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ex4VLcq+6y7rtXALu2BlzJUHrMNkhh7ZMxXGyJnvmUAow87ybx2YWPk+LyXaYvAdk NvyXevKj2M5U6xRQPAStimyNUVZzTCg9kWlkWqkqZNdc4yDl3suKD9qjdbXWklPCGO +Xk1Ba/dcYQXl2aDLL0EwmX58LFtJI6sOGJPCMuk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiaolong Huang , David Howells , Marc Dionne , linux-afs@lists.infradead.org, Paolo Abeni Subject: [PATCH 5.16 0935/1017] rxrpc: fix some null-ptr-deref bugs in server_key.c Date: Tue, 5 Apr 2022 09:30:48 +0200 Message-Id: <20220405070421.968045401@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiaolong Huang commit ff8376ade4f668130385839cef586a0990f8ef87 upstream. 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 Fixes: 12da59fcab5a ("rxrpc: Hand server key parsing off to the security class") Link: https://lore.kernel.org/r/164865013439.2941502.8966285221215590921.stgit@warthog.procyon.org.uk Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/rxrpc/server_key.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/net/rxrpc/server_key.c +++ b/net/rxrpc/server_key.c @@ -84,6 +84,9 @@ static int rxrpc_preparse_s(struct key_p 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 { 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 * { const struct rxrpc_security *sec = key->payload.data[1]; - if (sec) + if (sec && sec->destroy_server_key) sec->destroy_server_key(key); }