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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,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 5C769C433F5 for ; Wed, 8 Sep 2021 21:11:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DCD160C3E for ; Wed, 8 Sep 2021 21:11:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233330AbhIHVMi (ORCPT ); Wed, 8 Sep 2021 17:12:38 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:54628 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233068AbhIHVMi (ORCPT ); Wed, 8 Sep 2021 17:12:38 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1631135489; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Fu5kMUZpxkX+s5Xzjbe5W/ZeaCin9i6TKC3Ug/LbFGk=; b=MKUkMumzzF+0be0JCG+ZKnKNNl6zmlRXBNuh6cepuXn6JRGI+UyG9/wPEJ0O5yfy46PErS NrTqfjMaPakQ9i5EiPzuW1Arnd+eoZb3rNCewboqj0zSrY4/cq9fimlSoidIn07LtalZbv XGD6uTfOOlv1i4AYHN+dndZmJ1lHBFjbMPhtKWmIDbohpwvcMVVR1ZgXPsizQtgDlXnMRv zoRLCepXaCINQPrcVYKkJCWwM3uR4vmQTTSnM3Kya7inLz0ivwZAtK1G7VuiOILjJTKE/I lg+IaBo81ekxAekilCNo6VWE/PRIcm22r+srMVxa5gfhaaj/qsYkW7wn5i95sA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1631135489; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Fu5kMUZpxkX+s5Xzjbe5W/ZeaCin9i6TKC3Ug/LbFGk=; b=rBUyok1IbfCsd+RX7ktrzmcXUqVcHxSTUBBYRiXvhNoJ32El16eCShGxpHL6wLnN2TKlO+ vlnQvmWy3PEBPkDw== To: Jens Axboe , syzbot , linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, io-uring@vger.kernel.org Subject: Re: [syzbot] general protection fault in hrtimer_start_range_ns In-Reply-To: <111a312d-ec11-be36-ac74-ef92c8896967@kernel.dk> References: <0000000000009eeadd05cb511b60@google.com> <875yvbf23g.ffs@tglx> <8bbede01-4a97-bf22-92ad-c05a562c9799@kernel.dk> <111a312d-ec11-be36-ac74-ef92c8896967@kernel.dk> Date: Wed, 08 Sep 2021 23:11:28 +0200 Message-ID: <87tuiueprz.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Sep 08 2021 at 11:20, Jens Axboe wrote: > On 9/8/21 11:02 AM, Jens Axboe wrote: >> On 9/8/21 10:45 AM, Thomas Gleixner wrote: >>> On Mon, Sep 06 2021 at 03:28, syzbot wrote: >>>> syzbot found the following issue on: >>>> >>>> HEAD commit: 835d31d319d9 Merge tag 'media/v5.15-1' of git://git.kernel.. >>>> git tree: upstream >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=14489886300000 >>>> kernel config: https://syzkaller.appspot.com/x/.config?x=d793523866f2daea >>>> dashboard link: https://syzkaller.appspot.com/bug?extid=b935db3fe409625cca1b >>>> compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1 >>>> >>>> Unfortunately, I don't have any reproducer for this issue yet. >>>> >>>> IMPORTANT: if you fix the issue, please add the following tag to the commit: >>>> Reported-by: syzbot+b935db3fe409625cca1b@syzkaller.appspotmail.com >>>> >>>> general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN >>>> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] >>>> CPU: 0 PID: 12936 Comm: iou-sqp-12929 Not tainted 5.14.0-syzkaller #0 >>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >>>> RIP: 0010:lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] >>> >>> That's almost certainly deferencing hrtimer->base and as that is NULL >>> this looks like a not initialized hrtimer. >> >> Does certainly look like that, I'll take a look. And agree the next one >> looks like the same thing. > > I think both are fallout from a regression that we had in linked > requests, where we'd queue requests that weren't fully prepared. Current > Linus -git should not have this problem: > > These were the two related fixes: > > io_uring: fix queueing half-created requests > io_uring: don't submit half-prepared drain request Makes sense and the backtraces in the changelogs point at the same class of problem. Thanks, tglx