From: Roberto Sassu <roberto.sassu@huawei.com>
To: <zohar@linux.ibm.com>, <mjg59@srcf.ucam.org>
Cc: <linux-integrity@vger.kernel.org>,
<linux-security-module@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
Roberto Sassu <roberto.sassu@huawei.com>,
Christian Brauner <christian.brauner@ubuntu.com>,
Andreas Gruenbacher <agruenba@redhat.com>
Subject: [PATCH v7 07/12] evm: Pass user namespace to set/remove xattr hooks
Date: Fri, 14 May 2021 17:27:48 +0200 [thread overview]
Message-ID: <20210514152753.982958-8-roberto.sassu@huawei.com> (raw)
In-Reply-To: <20210514152753.982958-1-roberto.sassu@huawei.com>
In preparation for 'evm: Allow setxattr() and setattr() for unmodified
metadata', this patch passes mnt_userns to the inode set/remove xattr hooks
so that the GID of the inode on an idmapped mount is correctly determined
by posix_acl_update_mode().
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
---
include/linux/evm.h | 12 ++++++++----
security/integrity/evm/evm_main.c | 17 +++++++++++------
security/security.c | 4 ++--
3 files changed, 21 insertions(+), 12 deletions(-)
diff --git a/include/linux/evm.h b/include/linux/evm.h
index 39bb17a8236b..31ef1dbbb3ac 100644
--- a/include/linux/evm.h
+++ b/include/linux/evm.h
@@ -23,13 +23,15 @@ extern enum integrity_status evm_verifyxattr(struct dentry *dentry,
struct integrity_iint_cache *iint);
extern int evm_inode_setattr(struct dentry *dentry, struct iattr *attr);
extern void evm_inode_post_setattr(struct dentry *dentry, int ia_valid);
-extern int evm_inode_setxattr(struct dentry *dentry, const char *name,
+extern int evm_inode_setxattr(struct user_namespace *mnt_userns,
+ struct dentry *dentry, const char *name,
const void *value, size_t size);
extern void evm_inode_post_setxattr(struct dentry *dentry,
const char *xattr_name,
const void *xattr_value,
size_t xattr_value_len);
-extern int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name);
+extern int evm_inode_removexattr(struct user_namespace *mnt_userns,
+ struct dentry *dentry, const char *xattr_name);
extern void evm_inode_post_removexattr(struct dentry *dentry,
const char *xattr_name);
extern int evm_inode_init_security(struct inode *inode,
@@ -72,7 +74,8 @@ static inline void evm_inode_post_setattr(struct dentry *dentry, int ia_valid)
return;
}
-static inline int evm_inode_setxattr(struct dentry *dentry, const char *name,
+static inline int evm_inode_setxattr(struct user_namespace *mnt_userns,
+ struct dentry *dentry, const char *name,
const void *value, size_t size)
{
return 0;
@@ -86,7 +89,8 @@ static inline void evm_inode_post_setxattr(struct dentry *dentry,
return;
}
-static inline int evm_inode_removexattr(struct dentry *dentry,
+static inline int evm_inode_removexattr(struct user_namespace *mnt_userns,
+ struct dentry *dentry,
const char *xattr_name)
{
return 0;
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 77259cc901e2..12cb0ff590af 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -342,7 +342,8 @@ static enum integrity_status evm_verify_current_integrity(struct dentry *dentry)
* For posix xattr acls only, permit security.evm, even if it currently
* doesn't exist, to be updated unless the EVM signature is immutable.
*/
-static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name,
+static int evm_protect_xattr(struct user_namespace *mnt_userns,
+ struct dentry *dentry, const char *xattr_name,
const void *xattr_value, size_t xattr_value_len)
{
enum integrity_status evm_status;
@@ -405,6 +406,7 @@ static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name,
/**
* evm_inode_setxattr - protect the EVM extended attribute
+ * @mnt_userns: user namespace of the idmapped mount
* @dentry: pointer to the affected dentry
* @xattr_name: pointer to the affected extended attribute name
* @xattr_value: pointer to the new extended attribute value
@@ -416,8 +418,9 @@ static int evm_protect_xattr(struct dentry *dentry, const char *xattr_name,
* userspace from writing HMAC value. Writing 'security.evm' requires
* requires CAP_SYS_ADMIN privileges.
*/
-int evm_inode_setxattr(struct dentry *dentry, const char *xattr_name,
- const void *xattr_value, size_t xattr_value_len)
+int evm_inode_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+ const char *xattr_name, const void *xattr_value,
+ size_t xattr_value_len)
{
const struct evm_ima_xattr_data *xattr_data = xattr_value;
@@ -434,19 +437,21 @@ int evm_inode_setxattr(struct dentry *dentry, const char *xattr_name,
xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG)
return -EPERM;
}
- return evm_protect_xattr(dentry, xattr_name, xattr_value,
+ return evm_protect_xattr(mnt_userns, dentry, xattr_name, xattr_value,
xattr_value_len);
}
/**
* evm_inode_removexattr - protect the EVM extended attribute
+ * @mnt_userns: user namespace of the idmapped mount
* @dentry: pointer to the affected dentry
* @xattr_name: pointer to the affected extended attribute name
*
* Removing 'security.evm' requires CAP_SYS_ADMIN privileges and that
* the current value is valid.
*/
-int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name)
+int evm_inode_removexattr(struct user_namespace *mnt_userns,
+ struct dentry *dentry, const char *xattr_name)
{
/* Policy permits modification of the protected xattrs even though
* there's no HMAC key loaded
@@ -454,7 +459,7 @@ int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name)
if (evm_initialized & EVM_ALLOW_METADATA_WRITES)
return 0;
- return evm_protect_xattr(dentry, xattr_name, NULL, 0);
+ return evm_protect_xattr(mnt_userns, dentry, xattr_name, NULL, 0);
}
static void evm_reset_status(struct inode *inode)
diff --git a/security/security.c b/security/security.c
index b38155b2de83..e9f8010a2341 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1354,7 +1354,7 @@ int security_inode_setxattr(struct user_namespace *mnt_userns,
ret = ima_inode_setxattr(dentry, name, value, size);
if (ret)
return ret;
- return evm_inode_setxattr(dentry, name, value, size);
+ return evm_inode_setxattr(mnt_userns, dentry, name, value, size);
}
void security_inode_post_setxattr(struct dentry *dentry, const char *name,
@@ -1399,7 +1399,7 @@ int security_inode_removexattr(struct user_namespace *mnt_userns,
ret = ima_inode_removexattr(dentry, name);
if (ret)
return ret;
- return evm_inode_removexattr(dentry, name);
+ return evm_inode_removexattr(mnt_userns, dentry, name);
}
int security_inode_need_killpriv(struct dentry *dentry)
--
2.25.1
next prev parent reply other threads:[~2021-05-14 15:29 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-14 15:27 [PATCH v7 00/12] evm: Improve usability of portable signatures Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 01/12] evm: Execute evm_inode_init_security() only when an HMAC key is loaded Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 02/12] evm: Load EVM key in ima_load_x509() to avoid appraisal Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 03/12] evm: Refuse EVM_ALLOW_METADATA_WRITES only if an HMAC key is loaded Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 04/12] evm: Introduce evm_revalidate_status() Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 05/12] evm: Introduce evm_hmac_disabled() to safely ignore verification errors Roberto Sassu
2021-05-20 8:48 ` [RESEND][PATCH " Roberto Sassu
2021-05-20 8:51 ` Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 06/12] evm: Allow xattr/attr operations for portable signatures Roberto Sassu
2021-05-14 15:27 ` Roberto Sassu [this message]
2021-05-14 15:27 ` [PATCH v7 08/12] evm: Allow setxattr() and setattr() for unmodified metadata Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 09/12] evm: Deprecate EVM_ALLOW_METADATA_WRITES Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 10/12] ima: Allow imasig requirement to be satisfied by EVM portable signatures Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 11/12] ima: Introduce template field evmsig and write to field sig as fallback Roberto Sassu
2021-05-14 15:27 ` [PATCH v7 12/12] ima: Don't remove security.ima if file must not be appraised Roberto Sassu
2021-05-20 18:55 ` [PATCH v7 00/12] evm: Improve usability of portable signatures Mimi Zohar
2021-05-21 7:07 ` Roberto Sassu
2021-05-21 17:31 ` Mimi Zohar
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