From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (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 E4EDB30EF96 for ; Fri, 27 Feb 2026 18:45:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772217929; cv=none; b=c13pDMczGc9+BCnpP7V0cz3abwrmn9MR7RQEjZDBEvX7lXV6LTXyEm9/yBqBVOXwHAY0Jh+sJgaEULoTA4K2BgmHTG3rRKJrBwg9AqM+Y9RP1k+HfmywiBEB9OtzFo7ZDatHZHGkzlBPaREYYPd25NmARNdps3BfeV5+YlCHYU0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772217929; c=relaxed/simple; bh=OV59z+v8QXYIGkHgeQ0HgUC5XX0G029Y4uNdyFJsBic=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=q9XqIuFg/JWWOODqzx1L0o6xZnI6lf0tAR0m+wIbYduyQoe3DDHncmdbAN9ol5fXbDfMgVpfQQUROwQNHG1/JIyuECzqMChONXzYzv5/ob8ghwfOSL85tS9KlITg819lt3nXWvrYJZczh6JUeytN6AzegPXFwXy4Dai83Z6g9r4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=F6U9hWoD; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="F6U9hWoD" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=xf/Xguk0i0ou334iTYbS1A9S5uLdl09+LA+LZNhDHek=; b=F6U9hWoDvVZ67toI1R9jIhZ8lD txK0qWYl6fjvhcwLoxzWjbE8iq4KmO8hZdkik7VQSR4WylINNAhn5Vhmt+w0wB52D6GeoZzFNGSiT CTJQUgB4/i8HB4mncSjT0yGs/uvljG3OdB9Y7XoBDZ5utrqYFZCHBL5yYKGVbjJuqJT/2K1+yLl7D 6r6VJbWeJ7YTw4z/9uCwkFIg8RkchmjFQUb15rNslMhr7WIqiuuOy+B5OwyejfKJgXa5v9zEK98ZN mEdA+S4qp3dIM/2zb4esN++JiGNzeVyKWNtP0rt44sYw67FjdVBRiGSTRRpQdfJ4oEfuoN9hx+/e4 i5jTRqRg==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1vw2se-00000008qsT-1AVr; Fri, 27 Feb 2026 18:48:04 +0000 Date: Fri, 27 Feb 2026 18:48:04 +0000 From: Al Viro To: hooanon05g@gmail.com Cc: linux-fsdevel@vger.kernel.org Subject: Re: v7.0-rc1, name_to_handle_at(..., AT_EMPTY_PATH) Message-ID: <20260227184804.GC3836593@ZenIV> References: <14544.1772189098@jrotkm2> <20260227152211.GB3836593@ZenIV> <26309.1772206864@jrotkm2> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <26309.1772206864@jrotkm2> Sender: Al Viro On Sat, Feb 28, 2026 at 12:41:04AM +0900, hooanon05g@gmail.com wrote: > Al Viro: > > This > > struct filename *getname_uflags(const char __user *filename, int uflags) > > { > > int flags = (uflags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; > > > > return getname_flags(filename, flags); > > } > > is where AT_EMPTY_PATH is handled; could you check the arguuments it's getting > > in your reproducer and argument passed to getname_flags()? > > getname_flags() is not a problem. > For me, the problem looks that LOOKUP_EMPTY is NOT passed to > path_lookupat(). Could you please show me a single place in path_lookupat() where we would check for for LOOKUP_EMPTY? The last point where LOOKUP_EMPTY (or AT_EMPTY_PATH) matters is (and had always been) getname_flags(); pathname resolution proper doesn't care. In theory some out-of-tree filesystem might have been playing silly buggers with LOOKUP_EMPTY in its ->d_revalidate(); there's no good reason for doing so, though, and none of the in-tree filesystems had ever tried to pull that off. Could you describe the reproducer in more details?