From nobody Tue Aug 29 20:16:39 2023 X-Original-To: current@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4RZzGg1Smpz4s9CQ for ; Tue, 29 Aug 2023 20:16:43 +0000 (UTC) (envelope-from dchagin@heemeyer.club) Received: from heemeyer.club (heemeyer.club [195.93.173.158]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4RZzGf518xz4gL0 for ; Tue, 29 Aug 2023 20:16:42 +0000 (UTC) (envelope-from dchagin@heemeyer.club) Authentication-Results: mx1.freebsd.org; none Received: from heemeyer.club (localhost [127.0.0.1]) by heemeyer.club (8.17.2/8.16.1) with ESMTP id 37TKGdb4072626; Tue, 29 Aug 2023 23:16:39 +0300 (MSK) (envelope-from dchagin@heemeyer.club) Received: (from dchagin@localhost) by heemeyer.club (8.17.2/8.16.1/Submit) id 37TKGdMT072625; Tue, 29 Aug 2023 23:16:39 +0300 (MSK) (envelope-from dchagin) Date: Tue, 29 Aug 2023 23:16:39 +0300 From: Dmitry Chagin To: Shawn Webb Cc: current@freebsd.org Subject: Re: Possible issue with linux xattr support? Message-ID: References: <20230829190258.uc67572553e4fq3v@mutt-hbsd> List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230829190258.uc67572553e4fq3v@mutt-hbsd> X-Spamd-Bar: ---- X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:61400, ipnet:195.93.173.0/24, country:RU] X-Rspamd-Queue-Id: 4RZzGf518xz4gL0 On Tue, Aug 29, 2023 at 03:02:58PM -0400, Shawn Webb wrote: > On Tue, Aug 29, 2023 at 05:45:51PM +0300, Dmitry Chagin wrote: > > On Tue, Aug 29, 2023 at 12:59:11PM +0200, Felix Palmen wrote: > > > * Dmitry Chagin [20230828 18:57]: > > > > On Mon, Aug 28, 2023 at 08:03:33AM +0200, Felix Palmen wrote: > > > > > * Cy Schubert [20230827 16:59]: > > > > > > > > > > > > If we are to break it to fix a problem, maybe a sysctl to enable/disable then? > > > > > > > > > > IMHO depends on the exact nature of the problem. If it's confirmed that > > > > > it (always and only) breaks for jailed processes, just disabling it for > > > > > them would be the better workaround. "No-op" calls won't break anything. > > > > > > > > > > > > > please, try: https://people.freebsd.org/~dchagin/xattrerror.patch > > > > > > Thanks, I can confirm this avoids the issue in both cases I experienced > > > (install from GNU coreutils and python). > > > > > thanks, this is the first half of the fix, it works for you due to you > > are running tools under unprivileged user, afaiu. The second I have > > tested by myself :) > > > > > If I understand this patch correctly, it completely avoids EPERM, > > > masking it as not supported, so callers should consider it non-fatal, > > > allowing to silently ignore writing of "system" attributes while still > > > keeping other functionality? > > > > > system namespace is accessible only for privileged user, for others Linux > > returns ENOTSUP. So many tools ignores this error, eg ls. > > > > the second: https://people.freebsd.org/~dchagin/sea_jailed.patch > > > > Try this under privileged user, please. > > Back in 2019, I had a similar issue: I needed access to be able to > read/write to the system extended attribute namespace from within a > jailed context. I wrote a rather simple patch that provides that > support on a per-jail basis: > > https://git.hardenedbsd.org/hardenedbsd/HardenedBSD/-/commit/96c85982b45e44a6105664c7068a92d0a61da2a3 > > Hopefully that's useful to someone. > Nice, thank you. I'd prefer to disable it by default, like on a host.