From patchwork Thu Nov 16 09:01:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13457714 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01BAAC47071 for ; Thu, 16 Nov 2023 09:02:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235709AbjKPJCI (ORCPT ); Thu, 16 Nov 2023 04:02:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235223AbjKPJCB (ORCPT ); Thu, 16 Nov 2023 04:02:01 -0500 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5DB7A4; Thu, 16 Nov 2023 01:01:57 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4SWDFz1fbHz9yTLB; Thu, 16 Nov 2023 16:48:23 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwAnY3Nq2lVlSdzEAA--.16671S3; Thu, 16 Nov 2023 10:01:43 +0100 (CET) From: Roberto Sassu To: casey@schaufler-ca.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Roberto Sassu , stable@vger.kernel.org Subject: [PATCH v3 1/5] smack: Set SMACK64TRANSMUTE only for dirs in smack_inode_setxattr() Date: Thu, 16 Nov 2023 10:01:21 +0100 Message-Id: <20231116090125.187209-2-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> References: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: LxC2BwAnY3Nq2lVlSdzEAA--.16671S3 X-Coremail-Antispam: 1UD129KBjvdXoWrtw1UKryUCFW8Gry7Jw4Utwb_yoWDCrg_Ga 40yas5XrZ8A3W7Zws7CwnY9Fn2gay8Xr1rGa1aya9Iya4rXw1rZa15GFyrAFZ8uw17Ga95 CFnxG34Yy347XjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbsAYFVCjjxCrM7AC8VAFwI0_Xr0_Wr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7IE14v26r18M2 8IrcIa0xkI8VCY1x0267AKxVWUCVW8JwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK 021l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r 4j6F4UM28EF7xvwVC2z280aVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4j 6r4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7V C0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j 6r4UM4x0Y48IcxkI7VAKI48JMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r 4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF 67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2I x0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2 z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnU UI43ZEXa7IU1M7K7UUUUU== X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQADBF1jj5aE+QAAsc X-CFilter-Loop: Reflected Precedence: bulk List-ID: From: Roberto Sassu Since the SMACK64TRANSMUTE xattr makes sense only for directories, enforce this restriction in smack_inode_setxattr(). Cc: stable@vger.kernel.org Fixes: 5c6d1125f8db ("Smack: Transmute labels on specified directories") # v2.6.38.x Signed-off-by: Roberto Sassu --- security/smack/smack_lsm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 53336d7daa93..0027803a43ac 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1313,7 +1313,8 @@ static int smack_inode_setxattr(struct mnt_idmap *idmap, check_star = 1; } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { check_priv = 1; - if (size != TRANS_TRUE_SIZE || + if (!S_ISDIR(d_backing_inode(dentry)->i_mode) || + size != TRANS_TRUE_SIZE || strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) rc = -EINVAL; } else From patchwork Thu Nov 16 09:01:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13457715 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB8C3C54FB9 for ; Thu, 16 Nov 2023 09:02:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344990AbjKPJCM (ORCPT ); Thu, 16 Nov 2023 04:02:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235703AbjKPJCH (ORCPT ); Thu, 16 Nov 2023 04:02:07 -0500 Received: from frasgout13.his.huawei.com (frasgout13.his.huawei.com [14.137.139.46]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A61BCD5B; Thu, 16 Nov 2023 01:02:02 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.227]) by frasgout13.his.huawei.com (SkyGuard) with ESMTP id 4SWDG61L4Bz9yMLQ; Thu, 16 Nov 2023 16:48:30 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwAnY3Nq2lVlSdzEAA--.16671S4; Thu, 16 Nov 2023 10:01:48 +0100 (CET) From: Roberto Sassu To: casey@schaufler-ca.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Roberto Sassu , stable@vger.kernel.org Subject: [PATCH v3 2/5] smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity() Date: Thu, 16 Nov 2023 10:01:22 +0100 Message-Id: <20231116090125.187209-3-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> References: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: LxC2BwAnY3Nq2lVlSdzEAA--.16671S4 X-Coremail-Antispam: 1UD129KBjvdXoW7Wr15tF17uw4xtrWfZFyxXwb_yoWkZwb_u3 4jyFykXrs8Z3W3Xa97Ar1Fvrn2g3ykJr1Fg3Wfta43Zay5Xr4kta15JF98WFW5Aw4fJ393 CFn8WFyfAw17XjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbsAYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7IE14v26r15M2 8IrcIa0xkI8VCY1x0267AKxVW8JVW5JwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK 021l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r 4j6F4UM28EF7xvwVC2z280aVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4j 6r4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7V C0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j 6r4UM4x0Y48IcxkI7VAKI48JMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r 4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF 67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2I x0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2 z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnU UI43ZEXa7IU8fcTPUUUUU== X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQADBF1jj5aE+QABsd X-CFilter-Loop: Reflected Precedence: bulk List-ID: From: Roberto Sassu If the SMACK64TRANSMUTE xattr is provided, and the inode is a directory, update the in-memory inode flags by setting SMK_INODE_TRANSMUTE. Cc: stable@vger.kernel.org Fixes: 5c6d1125f8db ("Smack: Transmute labels on specified directories") # v2.6.38.x Signed-off-by: Roberto Sassu --- security/smack/smack_lsm.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 0027803a43ac..7b6d7ddd6d36 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2855,6 +2855,15 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name, if (value == NULL || size > SMK_LONGLABEL || size == 0) return -EINVAL; + if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) { + if (!S_ISDIR(inode->i_mode) || size != TRANS_TRUE_SIZE || + strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) + return -EINVAL; + + nsp->smk_flags |= SMK_INODE_TRANSMUTE; + return 0; + } + skp = smk_import_entry(value, size); if (IS_ERR(skp)) return PTR_ERR(skp); From patchwork Thu Nov 16 09:01:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13457716 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D284EC47071 for ; Thu, 16 Nov 2023 09:02:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344976AbjKPJCW (ORCPT ); Thu, 16 Nov 2023 04:02:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344979AbjKPJCL (ORCPT ); Thu, 16 Nov 2023 04:02:11 -0500 Received: from frasgout12.his.huawei.com (frasgout12.his.huawei.com [14.137.139.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5790AD43; Thu, 16 Nov 2023 01:02:06 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4SWDBh1NpNz9v7bS; Thu, 16 Nov 2023 16:45:32 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwAnY3Nq2lVlSdzEAA--.16671S5; Thu, 16 Nov 2023 10:01:52 +0100 (CET) From: Roberto Sassu To: casey@schaufler-ca.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Roberto Sassu Subject: [PATCH v3 3/5] smack: Always determine inode labels in smack_inode_init_security() Date: Thu, 16 Nov 2023 10:01:23 +0100 Message-Id: <20231116090125.187209-4-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> References: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: LxC2BwAnY3Nq2lVlSdzEAA--.16671S5 X-Coremail-Antispam: 1UD129KBjvJXoWxJFWkWr1rKry7tr1xGF1rJFb_yoWrGr17pF WUWa9xCr1DtFnxu3y0yF47Ww4a9as5Cr4UWr9Fqr9avFsrtryIgFW0qryYgFyxXr97ZrnY qr4avryrZ3WY9wUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvlb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8JVWxJwA2z4x0Y4vEx4A2jsIE14v26r4j6F4UM28EF7xvwVC2z280aVCY1x0267AKxVW8 JVW8Jr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx 0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWU JVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJV W8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF 1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6x IIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvE x4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvj DU0xZFpf9x07UAkuxUUUUU= X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQADBF1jj5aE+QACse X-CFilter-Loop: Reflected Precedence: bulk List-ID: From: Roberto Sassu The inode_init_security hook is already a good place to initialize the in-memory inode. And that is also what SELinux does. In preparation for this, move the existing smack_inode_init_security() code outside the 'if (xattr)' condition, and set the xattr, if provided. This change does not have any impact on the current code, since every time security_inode_init_security() is called, the initxattr() callback is passed and, thus, xattr is non-NULL. Signed-off-by: Roberto Sassu --- security/smack/smack_lsm.c | 78 +++++++++++++++++++------------------- 1 file changed, 39 insertions(+), 39 deletions(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 7b6d7ddd6d36..72f97492f5c3 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -999,51 +999,51 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count); int may; - if (xattr) { - /* - * If equal, transmuting already occurred in - * smack_dentry_create_files_as(). No need to check again. - */ - if (tsp->smk_task != tsp->smk_transmuted) { - rcu_read_lock(); - may = smk_access_entry(skp->smk_known, dsp->smk_known, - &skp->smk_rules); - rcu_read_unlock(); - } + /* + * If equal, transmuting already occurred in + * smack_dentry_create_files_as(). No need to check again. + */ + if (tsp->smk_task != tsp->smk_transmuted) { + rcu_read_lock(); + may = smk_access_entry(skp->smk_known, dsp->smk_known, + &skp->smk_rules); + rcu_read_unlock(); + } + + /* + * In addition to having smk_task equal to smk_transmuted, + * if the access rule allows transmutation and the directory + * requests transmutation then by all means transmute. + * Mark the inode as changed. + */ + if ((tsp->smk_task == tsp->smk_transmuted) || + (may > 0 && ((may & MAY_TRANSMUTE) != 0) && + smk_inode_transmutable(dir))) { + struct xattr *xattr_transmute; /* - * In addition to having smk_task equal to smk_transmuted, - * if the access rule allows transmutation and the directory - * requests transmutation then by all means transmute. - * Mark the inode as changed. + * The caller of smack_dentry_create_files_as() + * should have overridden the current cred, so the + * inode label was already set correctly in + * smack_inode_alloc_security(). */ - if ((tsp->smk_task == tsp->smk_transmuted) || - (may > 0 && ((may & MAY_TRANSMUTE) != 0) && - smk_inode_transmutable(dir))) { - struct xattr *xattr_transmute; + if (tsp->smk_task != tsp->smk_transmuted) + isp = dsp; + xattr_transmute = lsm_get_xattr_slot(xattrs, + xattr_count); + if (xattr_transmute) { + xattr_transmute->value = kmemdup(TRANS_TRUE, + TRANS_TRUE_SIZE, + GFP_NOFS); + if (!xattr_transmute->value) + return -ENOMEM; - /* - * The caller of smack_dentry_create_files_as() - * should have overridden the current cred, so the - * inode label was already set correctly in - * smack_inode_alloc_security(). - */ - if (tsp->smk_task != tsp->smk_transmuted) - isp = dsp; - xattr_transmute = lsm_get_xattr_slot(xattrs, - xattr_count); - if (xattr_transmute) { - xattr_transmute->value = kmemdup(TRANS_TRUE, - TRANS_TRUE_SIZE, - GFP_NOFS); - if (!xattr_transmute->value) - return -ENOMEM; - - xattr_transmute->value_len = TRANS_TRUE_SIZE; - xattr_transmute->name = XATTR_SMACK_TRANSMUTE; - } + xattr_transmute->value_len = TRANS_TRUE_SIZE; + xattr_transmute->name = XATTR_SMACK_TRANSMUTE; } + } + if (xattr) { xattr->value = kstrdup(isp->smk_known, GFP_NOFS); if (!xattr->value) return -ENOMEM; From patchwork Thu Nov 16 09:01:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13457717 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6683EC197A0 for ; Thu, 16 Nov 2023 09:02:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235715AbjKPJCZ (ORCPT ); Thu, 16 Nov 2023 04:02:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345007AbjKPJCO (ORCPT ); Thu, 16 Nov 2023 04:02:14 -0500 Received: from frasgout12.his.huawei.com (frasgout12.his.huawei.com [14.137.139.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C7E1D4B; Thu, 16 Nov 2023 01:02:09 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.229]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4SWDBm30Bzz9ycMw; Thu, 16 Nov 2023 16:45:36 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwAnY3Nq2lVlSdzEAA--.16671S6; Thu, 16 Nov 2023 10:01:56 +0100 (CET) From: Roberto Sassu To: casey@schaufler-ca.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Roberto Sassu Subject: [PATCH v3 4/5] smack: Initialize the in-memory inode in smack_inode_init_security() Date: Thu, 16 Nov 2023 10:01:24 +0100 Message-Id: <20231116090125.187209-5-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> References: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: LxC2BwAnY3Nq2lVlSdzEAA--.16671S6 X-Coremail-Antispam: 1UD129KBjvJXoWxCry8WFWfGF4kAw18GFW5Awb_yoW5Zw13pF Zxt3W7KwnYyF97WrWvyF47Ww1SkayFkr4UGrZxJr1xA3Zrtw1xKF1Fqr45ZF15Wr4kZa1F va1j9ry3WFn0y3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvKb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIE14v26r4j6F4UM28EF7xvwVC2z280aVCY1x0267AK xVW8JVW8Jr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2 WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkE bVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbV WUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF 67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42 IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF 0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxh VjvjDU0xZFpf9x07UZo7tUUUUU= X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgADBF1jj5KFoAAAsD X-CFilter-Loop: Reflected Precedence: bulk List-ID: From: Roberto Sassu Currently, Smack initializes in-memory new inodes in three steps. It first sets the xattrs in smack_inode_init_security(), fetches them in smack_d_instantiate() and finally, in the same function, sets the in-memory inodes depending on xattr values, unless they are in specially-handled filesystems. Other than being inefficient, this also prevents filesystems not supporting xattrs from working properly since, without xattrs, there is no way to pass the label determined in smack_inode_init_security() to smack_d_instantiate(). Since the LSM infrastructure allows setting and getting the security field without xattrs through the inode_setsecurity and inode_getsecurity hooks, make the inode creation work too, by initializing the in-memory inode earlier in smack_inode_init_security(). Also mark the inode as instantiated, to prevent smack_d_instantiate() from overwriting the security field. As mentioned above, this potentially has impact for inodes in specially-handled filesystems in smack_d_instantiate(), if they are not handled in the same way in smack_inode_init_security(). Filesystems other than tmpfs don't call security_inode_init_security(), so they would be always initialized in smack_d_instantiate(), as before. For tmpfs, the current behavior is to assign to inodes the label '*', but actually that label is overwritten with the one fetched from the SMACK64 xattr, set in smack_inode_init_security() (default: '_'). Initializing the in-memory inode is straightforward: if not transmuting, nothing more needs to be done; if transmuting, overwrite the current inode label with the one from the parent directory, and set SMK_INODE_TRANSMUTE. Finally, set SMK_INODE_INSTANT for all cases, to mark the inode as instantiated. Signed-off-by: Roberto Sassu --- security/smack/smack_lsm.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 72f97492f5c3..43e9389cbdfa 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -993,6 +993,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, struct xattr *xattrs, int *xattr_count) { struct task_smack *tsp = smack_cred(current_cred()); + struct inode_smack *issp = smack_inode(inode); struct smack_known *skp = smk_of_task(tsp); struct smack_known *isp = smk_of_inode(inode); struct smack_known *dsp = smk_of_inode(dir); @@ -1028,7 +1029,9 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, * smack_inode_alloc_security(). */ if (tsp->smk_task != tsp->smk_transmuted) - isp = dsp; + isp = issp->smk_inode = dsp; + + issp->smk_flags |= SMK_INODE_TRANSMUTE; xattr_transmute = lsm_get_xattr_slot(xattrs, xattr_count); if (xattr_transmute) { @@ -1043,6 +1046,8 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, } } + issp->smk_flags |= SMK_INODE_INSTANT; + if (xattr) { xattr->value = kstrdup(isp->smk_known, GFP_NOFS); if (!xattr->value) From patchwork Thu Nov 16 09:01:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13457720 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49D76C47071 for ; Thu, 16 Nov 2023 09:02:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344965AbjKPJCm (ORCPT ); Thu, 16 Nov 2023 04:02:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345024AbjKPJCZ (ORCPT ); Thu, 16 Nov 2023 04:02:25 -0500 Received: from frasgout12.his.huawei.com (frasgout12.his.huawei.com [14.137.139.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF9B9A4; Thu, 16 Nov 2023 01:02:20 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.229]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4SWDBy4mt2z9v7YZ; Thu, 16 Nov 2023 16:45:46 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwAnY3Nq2lVlSdzEAA--.16671S7; Thu, 16 Nov 2023 10:02:01 +0100 (CET) From: Roberto Sassu To: casey@schaufler-ca.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Roberto Sassu , Hugh Dickins , Andrew Morton Subject: [PATCH v3 5/5] ramfs: Initialize security of in-memory inodes Date: Thu, 16 Nov 2023 10:01:25 +0100 Message-Id: <20231116090125.187209-6-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> References: <20231116090125.187209-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: LxC2BwAnY3Nq2lVlSdzEAA--.16671S7 X-Coremail-Antispam: 1UD129KBjvJXoWxJF1ftr1UKrW5JF4UWrWktFb_yoW5GF4DpF 42qas8Gwn5XFyxWr1ftF4Duw1SgayfKr4DJw4xZw1xA3Z3Xw1DtF1Syr13CF1rJrW8Gw1I qr4Y9r1UC3W5ArJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvKb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWUCVW8JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIE14v26r4j6F4UM28EF7xvwVC2z280aVCY1x0267AK xVW8JVW8Jr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2 WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkE bVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbV WUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF 67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42 IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF 0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxh VjvjDU0xZFpf9x07UZo7tUUUUU= X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgADBF1jj5KFoAABsC X-CFilter-Loop: Reflected Precedence: bulk List-ID: From: Roberto Sassu Add a call security_inode_init_security() after ramfs_get_inode(), to let LSMs initialize the inode security field. Skip ramfs_fill_super(), as the initialization is done through the sb_set_mnt_opts hook. Calling security_inode_init_security() call inside ramfs_get_inode() is not possible since, for CONFIG_SHMEM=n, tmpfs also calls the former after the latter. Pass NULL as initxattrs() callback to security_inode_init_security(), since the purpose of the call is only to initialize the in-memory inodes. Cc: Hugh Dickins Cc: Andrew Morton Signed-off-by: Roberto Sassu Acked-by: Andrew Morton --- fs/ramfs/inode.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c index 4ac05a9e25bc..8006faaaf0ec 100644 --- a/fs/ramfs/inode.c +++ b/fs/ramfs/inode.c @@ -102,11 +102,20 @@ ramfs_mknod(struct mnt_idmap *idmap, struct inode *dir, int error = -ENOSPC; if (inode) { + error = security_inode_init_security(inode, dir, + &dentry->d_name, NULL, + NULL); + if (error) { + iput(inode); + goto out; + } + d_instantiate(dentry, inode); dget(dentry); /* Extra count - pin the dentry in core */ error = 0; inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); } +out: return error; } @@ -134,6 +143,15 @@ static int ramfs_symlink(struct mnt_idmap *idmap, struct inode *dir, inode = ramfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0); if (inode) { int l = strlen(symname)+1; + + error = security_inode_init_security(inode, dir, + &dentry->d_name, NULL, + NULL); + if (error) { + iput(inode); + goto out; + } + error = page_symlink(inode, symname, l); if (!error) { d_instantiate(dentry, inode); @@ -143,6 +161,7 @@ static int ramfs_symlink(struct mnt_idmap *idmap, struct inode *dir, } else iput(inode); } +out: return error; } @@ -150,12 +169,23 @@ static int ramfs_tmpfile(struct mnt_idmap *idmap, struct inode *dir, struct file *file, umode_t mode) { struct inode *inode; + int error; inode = ramfs_get_inode(dir->i_sb, dir, mode, 0); if (!inode) return -ENOSPC; + + error = security_inode_init_security(inode, dir, + &file_dentry(file)->d_name, NULL, + NULL); + if (error) { + iput(inode); + goto out; + } + d_tmpfile(file, inode); - return finish_open_simple(file, 0); +out: + return finish_open_simple(file, error); } static const struct inode_operations ramfs_dir_inode_operations = {