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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 7D263C4CEC9 for ; Wed, 18 Sep 2019 06:28:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 503F021906 for ; Wed, 18 Sep 2019 06:28:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568788128; bh=ndnVZThFnrsHfKpeo1GtWwshZV5PPDymC2h1oGnbKbw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=vak/CntNWpND4+aS4siJBKSXIwafI4JYfDmwUvGk1RxW90Pr6lUS+JbHqv+VDpwD1 uH7vwCUD5iyNfFLL5L5bpUWvno4nfifxWey5/N0A8E6oVQX16Q37X4daAdXYbdkvcF rrqsRXQWscU8PVXpp1oYEjtceQbEi2fZSXYiO+kg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730667AbfIRG2r (ORCPT ); Wed, 18 Sep 2019 02:28:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:50922 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729222AbfIRG2p (ORCPT ); Wed, 18 Sep 2019 02:28:45 -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 E737A21924; Wed, 18 Sep 2019 06:28:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568788124; bh=ndnVZThFnrsHfKpeo1GtWwshZV5PPDymC2h1oGnbKbw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=cB3Lk9V07SUyTgHZ+IJG1KHS1oCwZZR053yVd2GFV3LYn8SO+d8F45Cl5pG8c2Sfr pw+SBpxT0b2GV6zTcBU7yhIard1WFpxoesyp2kxBuPfdbw9USMet4W2tBl4gt6DlHF QomjysMb9z6CTfQx6/lvYGMRAx17RqRyUKUNOqrQ= Date: Wed, 18 Sep 2019 15:28:40 +0900 From: Masami Hiramatsu To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, syzkaller-bugs@googlegroups.com Subject: Re: [PATCH] tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink() Message-Id: <20190918152840.fbbf3a874d09f0c8203c7148@kernel.org> In-Reply-To: <20190917085643.26b86260@gandalf.local.home> References: <0000000000003006220592b41c5b@google.com> <156869709721.22406.5153754822203046939.stgit@devnote2> <20190917085643.26b86260@gandalf.local.home> 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 Tue, 17 Sep 2019 08:56:43 -0400 Steven Rostedt wrote: > On Tue, 17 Sep 2019 14:11:37 +0900 > Masami Hiramatsu wrote: > > > Fix NULL pointer access in trace_probe_unlink() by initializing > > trace_probe.list correctly in trace_probe_init(). > > > > In the error case of trace_probe_init(), it can call trace_probe_unlink() > > before initializing trace_probe.list member. This causes NULL pointer > > dereference at list_del_init() in trace_probe_unlink(). > > > > Syzbot reported : > > > > kasan: CONFIG_KASAN_INLINE enabled > > kasan: GPF could be caused by NULL-ptr deref or user memory access > > general protection fault: 0000 [#1] PREEMPT SMP KASAN > > CPU: 1 PID: 8633 Comm: syz-executor797 Not tainted 5.3.0-rc8-next-20190915 > > #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > RIP: 0010:__list_del_entry_valid+0x85/0xf5 lib/list_debug.c:51 > > Code: 0f 84 e1 00 00 00 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 e2 00 > > 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 > > 53 49 8b 14 24 4c 39 f2 0f 85 99 00 00 00 49 8d 7d > > RSP: 0018:ffff888090a7f9d8 EFLAGS: 00010246 > > RAX: dffffc0000000000 RBX: ffff88809b6f90c0 RCX: ffffffff817c0ca9 > > RDX: 0000000000000000 RSI: ffffffff817c0a73 RDI: ffff88809b6f90c8 > > RBP: ffff888090a7f9f0 R08: ffff88809a04e600 R09: ffffed1015d26aed > > R10: ffffed1015d26aec R11: ffff8880ae935763 R12: 0000000000000000 > > R13: 0000000000000000 R14: ffff88809b6f90c0 R15: ffff88809b6f90d0 > > FS: 0000555556f99880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00000000006cc090 CR3: 00000000962b2000 CR4: 00000000001406e0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > __list_del_entry include/linux/list.h:131 [inline] > > list_del_init include/linux/list.h:190 [inline] > > trace_probe_unlink+0x1f/0x200 kernel/trace/trace_probe.c:959 > > trace_probe_cleanup+0xd3/0x110 kernel/trace/trace_probe.c:973 > > trace_probe_init+0x3f2/0x510 kernel/trace/trace_probe.c:1011 > > alloc_trace_uprobe+0x5e/0x250 kernel/trace/trace_uprobe.c:353 > > create_local_trace_uprobe+0x109/0x4a0 kernel/trace/trace_uprobe.c:1508 > > perf_uprobe_init+0x131/0x210 kernel/trace/trace_event_perf.c:314 > > perf_uprobe_event_init+0x106/0x1a0 kernel/events/core.c:8898 > > perf_try_init_event+0x135/0x590 kernel/events/core.c:10184 > > perf_init_event kernel/events/core.c:10228 [inline] > > perf_event_alloc.part.0+0x1b89/0x33d0 kernel/events/core.c:10505 > > perf_event_alloc kernel/events/core.c:10887 [inline] > > __do_sys_perf_event_open+0xa2d/0x2d00 kernel/events/core.c:10989 > > __se_sys_perf_event_open kernel/events/core.c:10871 [inline] > > __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10871 > > do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > Reported-by: syzbot+2f807f4d3a2a4e87f18f@syzkaller.appspotmail.com > > Fixes: ca89bc071d5e ("tracing/kprobe: Add multi-probe per event support") > > Signed-off-by: Masami Hiramatsu > > Thanks Masami. I was just about to get my pull request to Linus out, > but will now add this and start running my tests with it. Thanks Steve, and sorry, I found another issue on multiprobe. I'll send it soon. Thank you, -- Masami Hiramatsu