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=-6.8 required=3.0 tests=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 BB604C31E51 for ; Sat, 15 Jun 2019 12:43:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E1152184E for ; Sat, 15 Jun 2019 12:43:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726796AbfFOMnQ (ORCPT ); Sat, 15 Jun 2019 08:43:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:33128 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726700AbfFOMnO (ORCPT ); Sat, 15 Jun 2019 08:43:14 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 11DDD2184C; Sat, 15 Jun 2019 12:43:14 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.92) (envelope-from ) id 1hc81Z-0006de-5P; Sat, 15 Jun 2019 08:43:13 -0400 Message-Id: <20190615124313.055864181@goodmis.org> User-Agent: quilt/0.65 Date: Sat, 15 Jun 2019 08:42:20 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , stable@vger.kernel.org, Srikar Dronamraju , Eiichi Tsukata Subject: [for-linus][PATCH 4/7] tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create() References: <20190615124216.188179157@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eiichi Tsukata 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 Link: http://lkml.kernel.org/r/20190614074026.8045-1-devel@etsukata.com Cc: stable@vger.kernel.org Fixes: 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for uprobe events") Reviewed-by: Srikar Dronamraju Signed-off-by: Eiichi Tsukata Signed-off-by: Steven Rostedt (VMware) --- 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 eb7e06b54741..a88c692e3b8a 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] == ':') -- 2.20.1