From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail115-95.sinamail.sina.com.cn (mail115-95.sinamail.sina.com.cn [218.30.115.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CC5951922CF for ; Thu, 17 Oct 2024 11:41:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=218.30.115.95 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729165320; cv=none; b=dNArrd+2+eGPsuH1bwPw07ag3eztruSCFn754i0c/zMReoat3Tfdi/lo0pNPzBtZM3ACuL68xSTypGrrHz2m/mwm3HdnLo7+aFHyQBn8MAU6LU8yYwpnP5c2vdCRCLBsg2lcrRbnPa4YT6XehDkIZhzLalyRyEUWQjgig57G3eY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729165320; c=relaxed/simple; bh=pkwjYMKa+senztZoorF8i0tIDopMMjUbI6qPxsoTdn4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZmBSwDWjSEeYjesG3KJDq5VM0RN6OPoLa32WQhxu78Aku72Ahz7tPXrvk9R0yPNyKGmSWN1GBtf/wojZ0xEL573eFhZB0SV+tJko+owQMv2Gx62TIB4gK3KhWrVyMseNHgX6FrlrTmyaTEXLGmWEXUDIsnKj8K03BHi6ir/Fy6A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.client-ip=218.30.115.95 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([113.118.70.59]) by sina.com (10.185.250.23) with ESMTP id 6710F76A000026F3; Thu, 17 Oct 2024 19:39:26 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 2332768913489 X-SMAIL-UIID: E9B7D3588EE7445DB8884F9B7DF6829E-20241017-193926-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [mm?] INFO: rcu detected stall in seq_read_iter (2) Date: Thu, 17 Oct 2024 19:39:15 +0800 Message-Id: <20241017113915.2052-1-hdanton@sina.com> In-Reply-To: <670fe136.050a0220.d9b66.016f.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Wed, 16 Oct 2024 08:52:22 -0700 > syzbot found the following issue on: > > HEAD commit: 9e4c6c1ad9a1 Merge tag 'io_uring-6.12-20241011' of git://g.. > git tree: upstream > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=161bf840580000 #syz test --- x/virt/kvm/kvm_main.c +++ y/virt/kvm/kvm_main.c @@ -6387,7 +6387,7 @@ static void kvm_sched_out(struct preempt WRITE_ONCE(vcpu->scheduled_out, true); - if (current->on_rq && vcpu->wants_to_run) { + if (current->on_rq && !current->se.sched_delayed && vcpu->wants_to_run) { WRITE_ONCE(vcpu->preempted, true); WRITE_ONCE(vcpu->ready, true); } --