From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 CDC0578F4F; Sun, 22 Mar 2026 11:47:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774180064; cv=none; b=UQ1sqMaEUaiZMch317ECwCSGePlwzVZo+pW+3ranhDU+Iro5O3BQBEFyk79e6ZeP4isg92DnMsndDeMLPa1MpVwdttLXUO9ZlVUeHf2XRgP6n9N9eTJi1NbtBIc8OwaOim23z7vN2RmjSRmsfZI5ojmweYQEsV2W8q1N7bXzJV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774180064; c=relaxed/simple; bh=AU2Fa0P7Cgq6/tXGq76ITNQfsi8b5PvDOJe85GVB7nc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cQc/U/bLhPsS0afd/4D3snk0n/2rPCbgRNM9AE6sncy5aB0zKNF8lZQ1avlYQipIVgF13Fj8lTSGyD4YXsE91xbjZk6SrDku5kToM8oHtbnE/wpFoLzq43KpdSTsbzWcA5xeP5L4S/JhKiDiFbO18noTQdZ39PwWsUPtKhRM91Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org; spf=none smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=wL/ZDJCd; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="wL/ZDJCd" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User: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=Wdswsvh/qjG6LMb+gNwEFa3/fTzcV89pe0MkygpRQWM=; b=wL/ZDJCdWVe/PRtHROIOBnKe9G +3oGpmEiHydAtA0e1KguCnpLvJHm9GvUEGHRPA2hfBYlsaN+0Z2T2IYaf3CyavQyUHdsx2q+PaLqp FCpfRtet3wKrCv4xgDB5Y1jRnn4JGarAK1hYt7BvG2V6zkkNElriyQ27mFWXRFAE8InAdEPjOCywA jDTR0ahwcdnedaPkQXugFIhCVPeU9ZPEB/DS0SJ4GZWdQhXmUtyCZvuOk1N1FA6OPEKojmiEF6DhC nYDTWvUTosTvy6VMxpjLC/bcZI4OH6IEdrXMhC68wSciB4fd0A59kJ64MaMNbdq5Ucb2IJHRPaX2x 9KpKT9zQ==; Received: from authenticated user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from ) id 1w4H7u-006j9b-Ed; Sun, 22 Mar 2026 11:37:49 +0000 Date: Sun, 22 Mar 2026 12:37:47 +0100 From: Chris Hofstaedtler To: Karel Zak Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, util-linux@vger.kernel.org, Christian Goeschel Ndjomouo , Helmut Grohne Subject: unshare regression in 2.42-rc1 Message-ID: References: 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=utf-8; format=flowed Content-Disposition: inline In-Reply-To: X-Debian-User: zeha Hi Karel, Christian, Debian CI found a regression in the unshare command when using --map-user with numeric UIDs. This worked in 2.41 and earlier: % unshare --version && unshare --user --map-auto --map-user=65536 id unshare from util-linux 2.41.3 uid=65536 gid=65534(nogroup) groups=65534(nogroup) And is broken in 2.42-rc1: % unshare --version && unshare --user --map-auto --map-user=65536 id unshare from util-linux 2.42-rc1 unshare: failed to parse uid '65536' Note the following (true in both cases): $ grep 65536 /etc/passwd % I suspect (but did not verify yet) this was introduced in commit 0a7fb806118bc4418e231081bd13c69bbc31b988 > unshare: use the new ul_get{grp,userpw}_str() routines > > This change refactors get_group() and get_user(), so that it > uses the new routines ul_getgrp_str() and ul_getuserpw_str(), > to simplify the code and remove the overkill mem allocations. https://github.com/util-linux/util-linux/commit/0a7fb806118bc4418e231081bd13c69bbc31b988 Thanks to Helmut Grohne for reducing the failed debvm CI run to the short unshare command. Best, Chris