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 22C4318A956; Mon, 10 Nov 2025 19:58:35 +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=1762804719; cv=none; b=Le9TY7xvCt/iELz0lCfI3sa0xQ/SYt+MoaQJL0sXU1icza4ChVg19BZVXwP6jF/YbATkWZYyBqAMi57DrjoF2D6y34tGpWQZc4tBnqVfQZfZouL1iSWDHtyMVPInijKFN0TtRsUq5bChM9uAroBwZeF+neSkdV5BwGxQGhVzKtA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762804719; c=relaxed/simple; bh=zzUMAVc+YltOZz/0m9lDa5bDZglHhhA+42+qMgWTBVM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ywlo+v9Bqiz7+HhFU7F6rqOjwzk5FKXcPWgsdCSh6dadzs5gUCmdEo58WHzRbC9+w2zgGmy7v/4zU86XmzibuXJI19to/aRn+Nufo0TRFvdnl+edubu7o7Ch6OZ6YyV6ICKsiPZ1eB74fgMomCpps6v9yihqznwQ2XGu3tCP97Q= 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=jUDCKcBp; 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="jUDCKcBp" 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=6P0jRtBdbPeH9TaBadc+VJlhiYAMnrlWk/flaJZ0tDY=; b=jUDCKcBp4fnfkjSGgEAo0fqtHG hwJCCspPX1bf6ei8ytIFjFBw7Y1AV3+e8apSeeqPWQxKEtXNBvzhNRH/s27LKTME9wf6TusI7HpS5 Kj7Lr9iV6h54Gc/uI6+Z5pdHXMLEPMmfna6yUU1wCYscL+97KToHAT3KnZucmFCLv+gVM80o8dxUx YZ4gQ2wCXieqcEE0XzBPvoNIjBJDY7yzMibhH3NYSC274xYxYDKWDLFYfcmDb0zXpVyhbPOmioOnq 2R2+08spG7Pc1FKFB40Xz8eXb/fYWu0HbnneXYSPxASdyiXa6w/5/ID9QBncqLsE62l3c1lh76Fxd 5N/vyZNA==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vIY25-0000000Gb8H-2eaC; Mon, 10 Nov 2025 19:58:33 +0000 Date: Mon, 10 Nov 2025 19:58:33 +0000 From: Al Viro To: Linus Torvalds Cc: linux-fsdevel@vger.kernel.org, brauner@kernel.org, jack@suse.cz, mjguzik@gmail.com, paul@paul-moore.com, axboe@kernel.dk, audit@vger.kernel.org, io-uring@vger.kernel.org Subject: Re: [RFC][PATCH 10/13] get rid of audit_reusename() Message-ID: <20251110195833.GN2441659@ZenIV> References: <20251109063745.2089578-1-viro@zeniv.linux.org.uk> <20251109063745.2089578-11-viro@zeniv.linux.org.uk> <20251110051748.GJ2441659@ZenIV> 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: Sender: Al Viro On Mon, Nov 10, 2025 at 08:41:45AM -0800, Linus Torvalds wrote: > > IMO things like "xfs" or "ceph" don't look like pathnames - if > > anything, we ought to use copy_mount_string() for consistency with > > mount(2)... > > Oh, absolutely not. > > But that code certainly could just do strndup_user(). That's the > normal thing for "get a string from user space" these days, but it > didn't historically exist.. There would be a minor change in errors (s/ENAMETOOLONG/EINVAL/ and s/ENOENT/EINVAL/, AFAICS), but nobody really gives a damn, so... If we go that way, do you see any problems with treating osf_{ufs,cdfs}_mount() in the same manner? Yes, these are pathnames, but the strings copied there are going to be fed (after another round of copying) to lookup_bdev(), i.e. getname_kernel(). At least that way it would be consistent with what mount(2) does... diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index a08e8edef1a4..21a8f985999b 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -454,42 +454,34 @@ static int osf_ufs_mount(const char __user *dirname, struct ufs_args __user *args, int flags) { - int retval; + char *devname __free(kfree) = NULL; struct cdfs_args tmp; - struct filename *devname; - retval = -EFAULT; if (copy_from_user(&tmp, args, sizeof(tmp))) - goto out; - devname = getname(tmp.devname); - retval = PTR_ERR(devname); + return -EFAULT; + + devname = strndup_user(tmp.devname, PATH_MAX); if (IS_ERR(devname)) - goto out; - retval = do_mount(devname->name, dirname, "ext2", flags, NULL); - putname(devname); - out: - return retval; + return PTR_ERR(devname); + + return do_mount(devname, dirname, "ext2", flags, NULL); } static int osf_cdfs_mount(const char __user *dirname, struct cdfs_args __user *args, int flags) { - int retval; + char *devname __free(kfree) = NULL; struct cdfs_args tmp; - struct filename *devname; - retval = -EFAULT; if (copy_from_user(&tmp, args, sizeof(tmp))) - goto out; - devname = getname(tmp.devname); - retval = PTR_ERR(devname); + return -EFAULT; + + devname = strndup_user(tmp.devname, PATH_MAX); if (IS_ERR(devname)) - goto out; - retval = do_mount(devname->name, dirname, "iso9660", flags, NULL); - putname(devname); - out: - return retval; + return PTR_ERR(devname); + + return do_mount(devname, dirname, "iso9660", flags, NULL); } static int