From patchwork Thu Jun 25 16:29:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 279426 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2417FC433E0 for ; Thu, 25 Jun 2020 16:30:41 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DF35320675 for ; Thu, 25 Jun 2020 16:30:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SPshYVGD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF35320675 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39676 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1joUls-0003fj-5a for qemu-devel@archiver.kernel.org; Thu, 25 Jun 2020 12:30:40 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57300) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1joUky-0002dT-2t for qemu-devel@nongnu.org; Thu, 25 Jun 2020 12:29:44 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:35230 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1joUkw-0002TK-Hv for qemu-devel@nongnu.org; Thu, 25 Jun 2020 12:29:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593102581; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=T6DlQfx4ERDr8imxa0nlFWolD5gVXxlxA3CSYrP+pEw=; b=SPshYVGD0lK3P1OPwIPo2ijZZr+GVUnde+YZutw9zW8SZnKlrOUmmiJpIAQNoW3J+nbPyZ 3jvhGs88IvjjElQy8ic0g8rES2SgQKxosFLnpCO/nKKmROb0H/Z8Pk1XkiBsdD/N5idxYP gzEf44UP91XBWc7N9jI9z2aWUjw773E= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-514-dedZBiT3OQa9MUuDXW83PQ-1; Thu, 25 Jun 2020 12:29:40 -0400 X-MC-Unique: dedZBiT3OQa9MUuDXW83PQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5E189464 for ; Thu, 25 Jun 2020 16:29:39 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-114-254.ams2.redhat.com [10.36.114.254]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6003DA09BF; Thu, 25 Jun 2020 16:29:38 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, virtio-fs@redhat.com, stefanha@redhat.com, vgoyal@redhat.com Subject: [PATCH 1/3] virtiofsd: Terminate capability list Date: Thu, 25 Jun 2020 17:29:27 +0100 Message-Id: <20200625162929.46672-2-dgilbert@redhat.com> In-Reply-To: <20200625162929.46672-1-dgilbert@redhat.com> References: <20200625162929.46672-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/25 00:45:15 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" capng_updatev is a varargs function that needs a -1 to terminate it, but it was missing. In practice what seems to have been happening is that it's added the capabilities we asked for, then runs into junk on the stack, so if we're unlucky it might be adding some more, but in reality it's failing - but after adding the capabilities we asked for. Fixes: a59feb483b8 ("virtiofsd: only retain file system capabilities") Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/passthrough_ll.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 2ce7c96085..e373e3b36e 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2598,7 +2598,9 @@ static void setup_capabilities(void) CAP_SETGID, CAP_SETUID, CAP_MKNOD, - CAP_SETFCAP); + CAP_SETFCAP, + -1); + capng_apply(CAPNG_SELECT_BOTH); cap.saved = capng_save_state(); From patchwork Thu Jun 25 16:29:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 279425 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EC6AC433E0 for ; Thu, 25 Jun 2020 16:32:25 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2B797206C3 for ; Thu, 25 Jun 2020 16:32:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aZApb+5R" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B797206C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:43918 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1joUnY-0005Tu-BI for qemu-devel@archiver.kernel.org; Thu, 25 Jun 2020 12:32:24 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57336) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1joUl1-0002jL-LM for qemu-devel@nongnu.org; Thu, 25 Jun 2020 12:29:47 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:55551 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1joUkz-0002Tz-Pg for qemu-devel@nongnu.org; Thu, 25 Jun 2020 12:29:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593102584; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Q9U7MZpedfnTjTu3sSF+WyTG3/6YQv3VnFsF74dLz3s=; b=aZApb+5R1fhSIfT+HnWIH7sokPj//Q36HzOHw8vQJAqOIyfXZlUrrZdtZN4THKollMd3QE 1a1BkliyveUX7HcnXFNvfXlydflFwoZvxp1M4K2N4slRXprhUQykmd8Sgg8ycXZYCn1xPZ lO4h114pa4yvzJy/SjkuRU96rLaJHP8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-159-O0udD3FNO3-Bc5L49pYJlw-1; Thu, 25 Jun 2020 12:29:42 -0400 X-MC-Unique: O0udD3FNO3-Bc5L49pYJlw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E47DF107ACCA for ; Thu, 25 Jun 2020 16:29:41 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-114-254.ams2.redhat.com [10.36.114.254]) by smtp.corp.redhat.com (Postfix) with ESMTP id E9E0CA09BF; Thu, 25 Jun 2020 16:29:40 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, virtio-fs@redhat.com, stefanha@redhat.com, vgoyal@redhat.com Subject: [PATCH 3/3] virtiofsd: Allow addition or removal of capabilities Date: Thu, 25 Jun 2020 17:29:29 +0100 Message-Id: <20200625162929.46672-4-dgilbert@redhat.com> In-Reply-To: <20200625162929.46672-1-dgilbert@redhat.com> References: <20200625162929.46672-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.120; envelope-from=dgilbert@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/25 01:47:53 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" Allow capabilities to be added or removed from the allowed set for the daemon; e.g. default: CapPrm: 00000000880000df CapEff: 00000000880000df -o modcaps=+sys_admin CapPrm: 00000000882000df CapEff: 00000000882000df -o modcaps=+sys_admin:-chown CapPrm: 00000000882000de CapEff: 00000000882000de Signed-off-by: Dr. David Alan Gilbert --- docs/tools/virtiofsd.rst | 5 ++++ tools/virtiofsd/helper.c | 2 ++ tools/virtiofsd/passthrough_ll.c | 50 ++++++++++++++++++++++++++++++-- 3 files changed, 55 insertions(+), 2 deletions(-) diff --git a/docs/tools/virtiofsd.rst b/docs/tools/virtiofsd.rst index 378594c422..824e713491 100644 --- a/docs/tools/virtiofsd.rst +++ b/docs/tools/virtiofsd.rst @@ -54,6 +54,11 @@ Options * flock|no_flock - Enable/disable flock. The default is ``no_flock``. + * modcaps=CAPLIST + Modify the list of capabilities allowed; CAPLIST is a colon separated + list of capabilities, each preceded by either + or -, e.g. + ''+sys_admin:-chown''. + * log_level=LEVEL - Print only log messages matching LEVEL or more severe. LEVEL is one of ``err``, ``warn``, ``info``, or ``debug``. The default is ``info``. diff --git a/tools/virtiofsd/helper.c b/tools/virtiofsd/helper.c index 00a1ef666a..3105b6c23a 100644 --- a/tools/virtiofsd/helper.c +++ b/tools/virtiofsd/helper.c @@ -174,6 +174,8 @@ void fuse_cmdline_help(void) " default: no_writeback\n" " -o xattr|no_xattr enable/disable xattr\n" " default: no_xattr\n" + " -o modcaps=CAPLIST Modify the list of capabilities\n" + " e.g. -o modcaps=+sys_admin:-chown\n" " --rlimit-nofile= set maximum number of file descriptors\n" " (0 leaves rlimit unchanged)\n" " default: min(1000000, fs.file-max - 16384)\n" diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 99d562046a..9d2cbc70ca 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -145,6 +145,7 @@ struct lo_data { int posix_lock; int xattr; char *source; + char *modcaps; double timeout; int cache; int timeout_set; @@ -170,6 +171,7 @@ static const struct fuse_opt lo_opts[] = { { "no_posix_lock", offsetof(struct lo_data, posix_lock), 0 }, { "xattr", offsetof(struct lo_data, xattr), 1 }, { "no_xattr", offsetof(struct lo_data, xattr), 0 }, + { "modcaps=%s", offsetof(struct lo_data, modcaps), 0 }, { "timeout=%lf", offsetof(struct lo_data, timeout), 0 }, { "timeout=", offsetof(struct lo_data, timeout_set), 1 }, { "cache=none", offsetof(struct lo_data, cache), CACHE_NONE }, @@ -2571,7 +2573,7 @@ static void setup_mounts(const char *source) /* * Only keep whitelisted capabilities that are needed for file system operation */ -static void setup_capabilities(void) +static void setup_capabilities(struct lo_data *lo) { pthread_mutex_lock(&cap.mutex); capng_restore_state(&cap.saved); @@ -2604,6 +2606,50 @@ static void setup_capabilities(void) exit(1); } + /* + * The modcaps option is a colon separated list of caps, + * each preceded by either + or -. + */ + while (lo->modcaps) { + capng_act_t action; + int cap; + + char *next = strchr(lo->modcaps, ':'); + if (next) { + *next = '\0'; + next++; + } + + switch (lo->modcaps[0]) { + case '+': + action = CAPNG_ADD; + break; + + case '-': + action = CAPNG_DROP; + break; + + default: + fuse_log(FUSE_LOG_ERR, + "%s: Expecting '+'/'-' in modcaps but found '%c'\n", + __func__, lo->modcaps[0]); + exit(1); + } + cap = capng_name_to_capability(lo->modcaps + 1); + if (cap < 0) { + fuse_log(FUSE_LOG_ERR, "%s: Unknown capability '%s'\n", __func__, + lo->modcaps); + exit(1); + } + if (capng_update(action, CAPNG_PERMITTED | CAPNG_EFFECTIVE, cap)) { + fuse_log(FUSE_LOG_ERR, "%s: capng_update failed for '%s'\n", + __func__, lo->modcaps); + exit(1); + } + + lo->modcaps = next; + } + if (capng_apply(CAPNG_SELECT_BOTH)) { fuse_log(FUSE_LOG_ERR, "%s: capng_apply failed\n", __func__); exit(1); @@ -2627,7 +2673,7 @@ static void setup_sandbox(struct lo_data *lo, struct fuse_session *se, setup_namespaces(lo, se); setup_mounts(lo->source); setup_seccomp(enable_syslog); - setup_capabilities(); + setup_capabilities(lo); } /* Set the maximum number of open file descriptors */