From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail3-164.sinamail.sina.com.cn (mail3-164.sinamail.sina.com.cn [202.108.3.164]) (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 9CACC2144C7 for ; Fri, 28 Nov 2025 06:56:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.108.3.164 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764312975; cv=none; b=avlHZaF/AxNhwlLX2yjI+xmf5yu/aiRpKoopD/Q2r8hOsFwMuQsnQEYEYPvuC23BKDQqR4N/rKc1Rcc+KdhMWbtALKbzE7JXCxN6nh33ROuBOr+r87q1/GrEMJqbA+ziQQa99bXAEwMyNivA1UPJ6zaCuWOJQZRTlUGqWdJB6LA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764312975; c=relaxed/simple; bh=1ZG3147rzKf/MpmiMkOLNGaKIOpnFPvwpQP4dmLhM10=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TJkmCQeU4Ffw/GmpVvw/n5xppUjLp+5Ro5iq0GBnQNbqIrphXRJysBJBS3v2c117jvfgRdotfJYtFcphLscIJuq6VM/Z/OPo1GSi0OJxvamGO6lSh+rgOCW+6PJlopoBcxOx2rBBjxpKgV+jKi5OuBsHRWEuXxgU7mkyra9oIps= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=WrKWBNCG; arc=none smtp.client-ip=202.108.3.164 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="WrKWBNCG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1764312969; bh=9hqMFboRXThJm8RmmDwySWiFPZsFFrgKHkWER5012bY=; h=From:Subject:Date:Message-ID; b=WrKWBNCGPG7tI5lCrmWPLIgWTmbJj0uI/dk4exEYxSEalB05+5tdej3CO7K4zfzi/ SNvy8NqeNXDd2+fokyJpMwHJQfuvgvP114xve0TwxJaevVwD189VeZhlo6Eh1mhW9N 2KSyJ3TZUgCyWIwyW2iTEMhHyHAKDIde6GSm56P8= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.57.85]) by sina.com (10.54.253.32) with ESMTP id 69294761000074FA; Fri, 28 Nov 2025 14:55:31 +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: 3487464456635 X-SMAIL-UIID: 4A29E4F5F0A0487581C45017AD83C0D7-20251128-145531-1 From: Hillf Danton To: syzbot Cc: NeilBrown , amir73il@gmail.com, brauner@kernel.org, linux-kernel@vger.kernel.org, linux-unionfs@vger.kernel.org, miklos@szeredi.hu, syzkaller-bugs@googlegroups.com, NeilBrown Subject: Re: [PATCH] ovl: fail ovl_lock_rename_workdir() if either target is unhashed Date: Fri, 28 Nov 2025 14:55:20 +0800 Message-ID: <20251128065521.9509-1-hdanton@sina.com> In-Reply-To: <176429295510.634289.1552337113663461690@noble.neil.brown.name> References: <6928b64f.a70a0220.d98e3.0115.GAE@google.com> Precedence: bulk X-Mailing-List: linux-unionfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit #syz test upstream master From: NeilBrown As well as checking that the parent hasn't changed after getting the lock we need to check that the dentry hasn't been unhashed. Otherwise we might try to rename something that has been removed. Reported-by: syzbot+bfc9a0ccf0de47d04e8c@syzkaller.appspotmail.com Fixes: d2c995581c7c ("ovl: Call ovl_create_temp() without lock held.") Signed-off-by: NeilBrown --- fs/overlayfs/util.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index f76672f2e686..82373dd1ce6e 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -1234,9 +1234,9 @@ int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *work, goto err; if (trap) goto err_unlock; - if (work && work->d_parent != workdir) + if (work && (work->d_parent != workdir || d_unhashed(work))) goto err_unlock; - if (upper && upper->d_parent != upperdir) + if (upper && (upper->d_parent != upperdir || d_unhashed(upper))) goto err_unlock; return 0; -- 2.50.0.107.gf914562f5916.dirty