lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20240711111908.3817636-6-xukuohai@huaweicloud.com>
Date: Thu, 11 Jul 2024 19:18:53 +0800
From: Xu Kuohai <xukuohai@...weicloud.com>
To: bpf@...r.kernel.org,
	netdev@...r.kernel.org,
	linux-security-module@...r.kernel.org,
	linux-kselftest@...r.kernel.org,
	linux-integrity@...r.kernel.org,
	apparmor@...ts.ubuntu.com,
	selinux@...r.kernel.org
Cc: Alexei Starovoitov <ast@...nel.org>,
	Andrii Nakryiko <andrii@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	Martin KaFai Lau <martin.lau@...ux.dev>,
	Eduard Zingerman <eddyz87@...il.com>,
	Song Liu <song@...nel.org>,
	Yonghong Song <yonghong.song@...ux.dev>,
	John Fastabend <john.fastabend@...il.com>,
	KP Singh <kpsingh@...nel.org>,
	Stanislav Fomichev <sdf@...gle.com>,
	Hao Luo <haoluo@...gle.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Matt Bobrowski <mattbobrowski@...gle.com>,
	Brendan Jackman <jackmanb@...omium.org>,
	Paul Moore <paul@...l-moore.com>,
	James Morris <jmorris@...ei.org>,
	"Serge E . Hallyn" <serge@...lyn.com>,
	Khadija Kamran <kamrankhadijadj@...il.com>,
	Casey Schaufler <casey@...aufler-ca.com>,
	Ondrej Mosnacek <omosnace@...hat.com>,
	Kees Cook <keescook@...omium.org>,
	John Johansen <john.johansen@...onical.com>,
	Lukas Bulwahn <lukas.bulwahn@...il.com>,
	Roberto Sassu <roberto.sassu@...wei.com>,
	Shung-Hsi Yu <shung-hsi.yu@...e.com>,
	Edward Cree <ecree.xilinx@...il.com>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Christian Brauner <brauner@...nel.org>,
	Trond Myklebust <trond.myklebust@...merspace.com>,
	Anna Schumaker <anna@...nel.org>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Stephen Smalley <stephen.smalley.work@...il.com>
Subject: [PATCH bpf-next v4 05/20] lsm: Refactor return value of LSM hook inode_copy_up_xattr

From: Xu Kuohai <xukuohai@...wei.com>

To be consistent with most LSM hooks, convert the return value of
hook inode_copy_up_xattr to 0 or a negative error code.

Before:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, 1 when
  discarding xattr, -EOPNOTSUPP if it does not know xattr, or any
  other negative error code otherwise.

After:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, *-ECANCELED*
  when discarding xattr, -EOPNOTSUPP if it does not know xattr, or
  any other negative error code otherwise.

Signed-off-by: Xu Kuohai <xukuohai@...wei.com>
---
 fs/overlayfs/copy_up.c            |  6 +++---
 security/integrity/evm/evm_main.c |  2 +-
 security/security.c               | 12 ++++++------
 security/selinux/hooks.c          |  4 ++--
 security/smack/smack_lsm.c        |  6 +++---
 5 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index a5ef2005a2cc..337a5be99ac9 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -115,12 +115,12 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de
 			continue;
 
 		error = security_inode_copy_up_xattr(old, name);
-		if (error < 0 && error != -EOPNOTSUPP)
-			break;
-		if (error == 1) {
+		if (error == -ECANCELED) {
 			error = 0;
 			continue; /* Discard */
 		}
+		if (error < 0 && error != -EOPNOTSUPP)
+			break;
 
 		if (is_posix_acl_xattr(name)) {
 			error = ovl_copy_acl(OVL_FS(sb), oldpath, new, name);
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 62fe66dd53ce..6924ed508ebd 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -1000,7 +1000,7 @@ static int evm_inode_copy_up_xattr(struct dentry *src, const char *name)
 	case EVM_XATTR_HMAC:
 	case EVM_IMA_XATTR_DIGSIG:
 	default:
-		rc = 1; /* discard */
+		rc = -ECANCELED; /* discard */
 	}
 
 	kfree(xattr_data);
diff --git a/security/security.c b/security/security.c
index 26eea8f4cd74..12215ca286af 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2675,18 +2675,18 @@ EXPORT_SYMBOL(security_inode_copy_up);
  * lower layer to the union/overlay layer.   The caller is responsible for
  * reading and writing the xattrs, this hook is merely a filter.
  *
- * Return: Returns 0 to accept the xattr, 1 to discard the xattr, -EOPNOTSUPP
- *         if the security module does not know about attribute, or a negative
- *         error code to abort the copy up.
+ * Return: Returns 0 to accept the xattr, -ECANCELED to discard the xattr,
+ *         -EOPNOTSUPP if the security module does not know about attribute,
+ *         or a negative error code to abort the copy up.
  */
 int security_inode_copy_up_xattr(struct dentry *src, const char *name)
 {
 	int rc;
 
 	/*
-	 * The implementation can return 0 (accept the xattr), 1 (discard the
-	 * xattr), -EOPNOTSUPP if it does not know anything about the xattr or
-	 * any other error code in case of an error.
+	 * The implementation can return 0 (accept the xattr), -ECANCELED
+	 * (discard the xattr), -EOPNOTSUPP if it does not know anything
+	 *  about the xattr or any other error code in case of an error.
 	 */
 	rc = call_int_hook(inode_copy_up_xattr, src, name);
 	if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr))
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5dedd3917d57..f9a6637dfd78 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3528,8 +3528,8 @@ static int selinux_inode_copy_up_xattr(struct dentry *dentry, const char *name)
 	 * xattrs up.  Instead, filter out SELinux-related xattrs following
 	 * policy load.
 	 */
-	if (selinux_initialized() && strcmp(name, XATTR_NAME_SELINUX) == 0)
-		return 1; /* Discard */
+	if (selinux_initialized() && !strcmp(name, XATTR_NAME_SELINUX))
+		return -ECANCELED; /* Discard */
 	/*
 	 * Any other attribute apart from SELINUX is not claimed, supported
 	 * by selinux.
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 6f73906bf7ea..ae8f1c2d0ca6 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4893,10 +4893,10 @@ static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
 static int smack_inode_copy_up_xattr(struct dentry *src, const char *name)
 {
 	/*
-	 * Return 1 if this is the smack access Smack attribute.
+	 * Return -ECANCELED if this is the smack access Smack attribute.
 	 */
-	if (strcmp(name, XATTR_NAME_SMACK) == 0)
-		return 1;
+	if (!strcmp(name, XATTR_NAME_SMACK))
+		return -ECANCELED;
 
 	return -EOPNOTSUPP;
 }
-- 
2.30.2


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ