From patchwork Wed Feb 21 21:24:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Seth Forshee (DigitalOcean)" X-Patchwork-Id: 13566389 X-Patchwork-Delegate: paul@paul-moore.com Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B53DB12A159; Wed, 21 Feb 2024 21:25:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708550706; cv=none; b=Hhr/StRxHc3WsK2BxTkX0KRd+v3FRga5bJuGpWPjuU/aldbaUUz7WrcHeLO5+IHS1QkwzSz/ues9CHEKj8Kiwyz9h8hRy6GeGqphwY4qvDZ+kjdjKTC3XAqoRGlXEAArTy0Tv/IZWsydkqSEKRXXoBe3eo/PhI7g1WydDLRDx7w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708550706; c=relaxed/simple; bh=bU1CcTjoAErUmCcImLT8MBeG6twr7o4CKTQE5qVrAgQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=R98W8t02rueguCO9l1ED1Zjm15qEUJfB5zTXEQztggDkyLx9HjvMHiT/cH/tMSZkJzJrHfPhDSaUDdHO12F7sN9d2brJhL1kC83EYAW7lE7CHXMdxnu6MNYaWYiT73M5oQQpm2kK6mCmQcMaYpY4JQzHKH+VlgZx0r1DFF6+W90= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FcGjqVa6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FcGjqVa6" Received: by smtp.kernel.org (Postfix) with ESMTPS id 787C8C32785; Wed, 21 Feb 2024 21:25:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708550706; bh=bU1CcTjoAErUmCcImLT8MBeG6twr7o4CKTQE5qVrAgQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=FcGjqVa6LFtv3wIisQX3ULDicQYa/7JUNgjsOxVOxVbBN2XRKtt4vccq6xj9Gg/UL 5W+QHPa31Tm++/4yeexKz1kIqJWieCefTCFEudO9BXLtaxfQ56UTNPEKKXwFOECfG0 zaxRPGXu6muDcX8/b2TWgdd++UA+Jv8tMmcuP7dZUhlshRqWZWnxUUceHir+xqAXNL /4Z/kBljMAkI3uBcjW2ihJRj0Z3WARjJKDXjYVmtXOC8oje28yVXhxoAoAEtkIumOt PkCru4mDI9qYc3RH/TkC/DUCv/G5BSkUKupMfd8XJszSZMRYhatK4ijIx3sWYNSG/1 rXQxNtC4NzCyA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64819C5478B; Wed, 21 Feb 2024 21:25:06 +0000 (UTC) From: "Seth Forshee (DigitalOcean)" Date: Wed, 21 Feb 2024 15:24:42 -0600 Subject: [PATCH v2 11/25] security: add hooks for set/get/remove of fscaps Precedence: bulk X-Mailing-List: audit@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240221-idmap-fscap-refactor-v2-11-3039364623bd@kernel.org> References: <20240221-idmap-fscap-refactor-v2-0-3039364623bd@kernel.org> In-Reply-To: <20240221-idmap-fscap-refactor-v2-0-3039364623bd@kernel.org> To: Christian Brauner , Seth Forshee , Serge Hallyn , Paul Moore , Eric Paris , James Morris , Alexander Viro , Jan Kara , Stephen Smalley , Ondrej Mosnacek , Casey Schaufler , Mimi Zohar , Roberto Sassu , Dmitry Kasatkin , Eric Snowberg , "Matthew Wilcox (Oracle)" , Jonathan Corbet , Miklos Szeredi , Amir Goldstein Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, audit@vger.kernel.org, selinux@vger.kernel.org, linux-integrity@vger.kernel.org, linux-doc@vger.kernel.org, linux-unionfs@vger.kernel.org X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=6068; i=sforshee@kernel.org; h=from:subject:message-id; bh=bU1CcTjoAErUmCcImLT8MBeG6twr7o4CKTQE5qVrAgQ=; =?utf-8?q?b=3DowEBbQGS/pANAwAKAVMDma7l9DHJAcsmYgBl1moiOmBWOkW3C2D6watYerA1n?= =?utf-8?q?6u6GpH/leMlBqw7_WLNKqEiJATMEAAEKAB0WIQSQnt+rKAvnETy4Hc9TA5mu5fQxy?= =?utf-8?q?QUCZdZqIgAKCRBTA5mu5fQxyX4hB/_4gHtUbOV115lPuC//xfy9D4S1XJ5dcZzKpX?= =?utf-8?q?27IoQgRAB8iadS9qTPZMY9JzN+fEAEJjKFFAFM94cF0_rLytBPDiTKSoKBhm83DGI?= =?utf-8?q?fLJyy9gdXXFGXFzmy5MzY4VkuLjCzBltyOieqCT8M64K49wiTDIWCrTku_mf3oZbj?= =?utf-8?q?kX8CKEyWzC5OjK08smBtBMLPrNQbDTlb5J2i75XOVmI2yrPuZMCJojB8IN39jKaJ8?= =?utf-8?q?UX3Hjc_HElICYbTk+WAYh9ZuZUpzzyo7IEH0c3YjbR8PLFH7Xg0ZTT5jPH6Ccksrf?= =?utf-8?q?7oNmjUcAAUf7e/S7Xd7K?= vW7wHQVxNqrw0G7gjCWEoB0nJW9wrt X-Developer-Key: i=sforshee@kernel.org; a=openpgp; fpr=2ABCA7498D83E1D32D51D3B5AB4800A62DB9F73A X-Endpoint-Received: by B4 Relay for sforshee@kernel.org/default with auth_id=103 In preparation for moving fscaps out of the xattr code paths, add new security hooks. These hooks are largely needed because common kernel code will pass around struct vfs_caps pointers, which EVM will need to convert to raw xattr data for verification and updates of its hashes. Signed-off-by: Seth Forshee (DigitalOcean) Acked-by: Paul Moore Reviewed-by: Christian Brauner --- include/linux/lsm_hook_defs.h | 7 +++++ include/linux/security.h | 33 +++++++++++++++++++++ security/security.c | 69 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 109 insertions(+) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 76458b6d53da..7b3c23f9e4a5 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -152,6 +152,13 @@ LSM_HOOK(int, 0, inode_get_acl, struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) LSM_HOOK(int, 0, inode_remove_acl, struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) +LSM_HOOK(int, 0, inode_set_fscaps, struct mnt_idmap *idmap, + struct dentry *dentry, const struct vfs_caps *caps, int flags); +LSM_HOOK(void, LSM_RET_VOID, inode_post_set_fscaps, struct mnt_idmap *idmap, + struct dentry *dentry, const struct vfs_caps *caps, int flags); +LSM_HOOK(int, 0, inode_get_fscaps, struct mnt_idmap *idmap, struct dentry *dentry); +LSM_HOOK(int, 0, inode_remove_fscaps, struct mnt_idmap *idmap, + struct dentry *dentry); LSM_HOOK(int, 0, inode_need_killpriv, struct dentry *dentry) LSM_HOOK(int, 0, inode_killpriv, struct mnt_idmap *idmap, struct dentry *dentry) diff --git a/include/linux/security.h b/include/linux/security.h index d0eb20f90b26..40be548e5e12 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -378,6 +378,13 @@ int security_inode_getxattr(struct dentry *dentry, const char *name); int security_inode_listxattr(struct dentry *dentry); int security_inode_removexattr(struct mnt_idmap *idmap, struct dentry *dentry, const char *name); +int security_inode_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry, + const struct vfs_caps *caps, int flags); +void security_inode_post_set_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry, + const struct vfs_caps *caps, int flags); +int security_inode_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry); +int security_inode_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry); int security_inode_need_killpriv(struct dentry *dentry); int security_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry); int security_inode_getsecurity(struct mnt_idmap *idmap, @@ -935,6 +942,32 @@ static inline int security_inode_removexattr(struct mnt_idmap *idmap, return cap_inode_removexattr(idmap, dentry, name); } +static inline int security_inode_set_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry, + const struct vfs_caps *caps, + int flags) +{ + return 0; +} +static void security_inode_post_set_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry, + const struct vfs_caps *caps, + int flags) +{ +} + +static int security_inode_get_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry) +{ + return 0; +} + +static int security_inode_remove_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry) +{ + return 0; +} + static inline int security_inode_need_killpriv(struct dentry *dentry) { return cap_inode_need_killpriv(dentry); diff --git a/security/security.c b/security/security.c index 3aaad75c9ce8..0d210da9862c 100644 --- a/security/security.c +++ b/security/security.c @@ -2351,6 +2351,75 @@ int security_inode_remove_acl(struct mnt_idmap *idmap, return evm_inode_remove_acl(idmap, dentry, acl_name); } +/** + * security_inode_set_fscaps() - Check if setting fscaps is allowed + * @idmap: idmap of the mount + * @dentry: file + * @caps: fscaps to be written + * @flags: flags for setxattr + * + * Check permission before setting the file capabilities given in @vfs_caps. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry, + const struct vfs_caps *caps, int flags) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_set_fscaps, 0, idmap, dentry, caps, flags); +} + +/** + * security_inode_post_set_fscaps() - Update the inode after setting fscaps + * @idmap: idmap of the mount + * @dentry: file + * @caps: fscaps to be written + * @flags: flags for setxattr + * + * Update inode security field after successfully setting fscaps. + * + */ +void security_inode_post_set_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry, + const struct vfs_caps *caps, int flags) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_set_fscaps, idmap, dentry, caps, flags); +} + +/** + * security_inode_get_fscaps() - Check if reading fscaps is allowed + * @dentry: file + * + * Check permission before getting fscaps. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_get_fscaps, 0, idmap, dentry); +} + +/** + * security_inode_remove_fscaps() - Check if removing fscaps is allowed + * @idmap: idmap of the mount + * @dentry: file + * + * Check permission before removing fscaps. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_remove_fscaps, 0, idmap, dentry); +} + /** * security_inode_post_setxattr() - Update the inode after a setxattr operation * @dentry: file