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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 169D1C43613 for ; Fri, 21 Jun 2019 14:22:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DFB3121537 for ; Fri, 21 Jun 2019 14:22:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561126955; bh=4IkqAOqT0zuSMeh/3c4/6vzmwnG02ofkxfCVizW9ijs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=gMHGW4IpblfldBWl7A2CI8r8mTK2YuV0ivOkjT4A/N4jyCI5ZReeEJCrVWYZcb8Qx vHRvR+5Hw/G8dBiKkpbvTqG2v06ITiiT/Jc+I13Sm7u1cm4bpx2rCyVuxiUyW7w84r ybFc39A7c4vIH7yjO19v+GhR1PCJuV3T3b+9Ns64= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726308AbfFUOWe (ORCPT ); Fri, 21 Jun 2019 10:22:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:51946 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725985AbfFUOWe (ORCPT ); Fri, 21 Jun 2019 10:22:34 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E1707206B7; Fri, 21 Jun 2019 14:22:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561126953; bh=4IkqAOqT0zuSMeh/3c4/6vzmwnG02ofkxfCVizW9ijs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BPTDbC7ngN+CpwQfUzE0r+b1tBpCeUldP1Pzj2Ch4HvUf+25FLweg32H7H5So/7Pj FcoGxR7pSjRLqNpdzYZhsIcXwI0vG0Y08AiKkpOEHj98rT9yVbOHUZ17EiORHjhkDF NR+XzLgBjtX1Ounqn3T6hfIwY6K0l6wQtpip49t8= Date: Fri, 21 Jun 2019 23:22:29 +0900 From: Masami Hiramatsu To: Eiichi Tsukata Cc: rostedt@goodmis.org, mingo@redhat.com, srikar@linux.vnet.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create() Message-Id: <20190621232229.9c488ee5ea260ea9bcc85a53@kernel.org> In-Reply-To: <20190614074026.8045-1-devel@etsukata.com> References: <20190614074026.8045-1-devel@etsukata.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 14 Jun 2019 16:40:25 +0900 Eiichi Tsukata wrote: > Just like the case of commit 8b05a3a7503c ("tracing/kprobes: Fix NULL > pointer dereference in trace_kprobe_create()"), writing an incorrectly > formatted string to uprobe_events can trigger NULL pointer dereference. > > Reporeducer: > > # echo r > /sys/kernel/debug/tracing/uprobe_events > > dmesg: > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 8000000079d12067 P4D 8000000079d12067 PUD 7b7ab067 PMD 0 > Oops: 0000 [#1] PREEMPT SMP PTI > CPU: 0 PID: 1903 Comm: bash Not tainted 5.2.0-rc3+ #15 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014 > RIP: 0010:strchr+0x0/0x30 > Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 84 00 00 00 00 00 <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c > RSP: 0018:ffffb55fc0403d10 EFLAGS: 00010293 > > RAX: ffff993ffb793400 RBX: 0000000000000000 RCX: ffffffffa4852625 > RDX: 0000000000000000 RSI: 000000000000002f RDI: 0000000000000000 > RBP: ffffb55fc0403dd0 R08: ffff993ffb793400 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: ffff993ff9cc1668 R14: 0000000000000001 R15: 0000000000000000 > FS: 00007f30c5147700(0000) GS:ffff993ffda00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000000 CR3: 000000007b628000 CR4: 00000000000006f0 > Call Trace: > trace_uprobe_create+0xe6/0xb10 > ? __kmalloc_track_caller+0xe6/0x1c0 > ? __kmalloc+0xf0/0x1d0 > ? trace_uprobe_create+0xb10/0xb10 > create_or_delete_trace_uprobe+0x35/0x90 > ? trace_uprobe_create+0xb10/0xb10 > trace_run_command+0x9c/0xb0 > trace_parse_run_command+0xf9/0x1eb > ? probes_open+0x80/0x80 > __vfs_write+0x43/0x90 > vfs_write+0x14a/0x2a0 > ksys_write+0xa2/0x170 > do_syscall_64+0x7f/0x200 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Fixes: 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for uprobe events") > Signed-off-by: Eiichi Tsukata Sorry, I missed this fix. Acked-by: Masami Hiramatsu Steve, could you pick this as an urgent fix? Thank you! > --- > kernel/trace/trace_uprobe.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 0d60d6856de5..7dc8ee55cf84 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -443,10 +443,17 @@ static int trace_uprobe_create(int argc, const char **argv) > ret = 0; > ref_ctr_offset = 0; > > - /* argc must be >= 1 */ > - if (argv[0][0] == 'r') > + switch (argv[0][0]) { > + case 'r': > is_return = true; > - else if (argv[0][0] != 'p' || argc < 2) > + break; > + case 'p': > + break; > + default: > + return -ECANCELED; > + } > + > + if (argc < 2) > return -ECANCELED; > > if (argv[0][1] == ':') > -- > 2.21.0 > -- Masami Hiramatsu