diff options
| -rw-r--r-- | fs/attr.c | 2 | ||||
| -rw-r--r-- | fs/posix_acl.c | 3 | ||||
| -rw-r--r-- | fs/xattr.c | 2 | ||||
| -rw-r--r-- | include/linux/evm.h | 113 | ||||
| -rw-r--r-- | include/uapi/linux/lsm.h | 1 | ||||
| -rw-r--r-- | security/integrity/evm/evm_main.c | 118 | ||||
| -rw-r--r-- | security/security.c | 43 | ||||
| -rw-r--r-- | tools/testing/selftests/lsm/lsm_list_modules_test.c | 3 |
8 files changed, 116 insertions, 169 deletions
diff --git a/fs/attr.c b/fs/attr.c index 7e97313e7f70..4d0d75953107 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -16,7 +16,6 @@ #include <linux/fcntl.h> #include <linux/filelock.h> #include <linux/security.h> -#include <linux/evm.h> #include "internal.h" @@ -502,7 +501,6 @@ int notify_change(struct mnt_idmap *idmap, struct dentry *dentry, if (!error) { fsnotify_change(dentry, ia_valid); security_inode_post_setattr(idmap, dentry, ia_valid); - evm_inode_post_setattr(idmap, dentry, ia_valid); } return error; diff --git a/fs/posix_acl.c b/fs/posix_acl.c index 0d2371240c1b..5c90239e3f2b 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -26,7 +26,6 @@ #include <linux/mnt_idmapping.h> #include <linux/iversion.h> #include <linux/security.h> -#include <linux/evm.h> #include <linux/fsnotify.h> #include <linux/filelock.h> @@ -1138,7 +1137,6 @@ retry_deleg: if (!error) { fsnotify_xattr(dentry); security_inode_post_set_acl(dentry, acl_name, kacl); - evm_inode_post_set_acl(dentry, acl_name, kacl); } out_inode_unlock: @@ -1247,7 +1245,6 @@ retry_deleg: if (!error) { fsnotify_xattr(dentry); security_inode_post_remove_acl(idmap, dentry, acl_name); - evm_inode_post_remove_acl(idmap, dentry, acl_name); } out_inode_unlock: diff --git a/fs/xattr.c b/fs/xattr.c index f891c260a971..f8b643f91a98 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -16,7 +16,6 @@ #include <linux/mount.h> #include <linux/namei.h> #include <linux/security.h> -#include <linux/evm.h> #include <linux/syscalls.h> #include <linux/export.h> #include <linux/fsnotify.h> @@ -557,7 +556,6 @@ __vfs_removexattr_locked(struct mnt_idmap *idmap, fsnotify_xattr(dentry); security_inode_post_removexattr(dentry, name); - evm_inode_post_removexattr(dentry, name); out: return error; diff --git a/include/linux/evm.h b/include/linux/evm.h index 3faabdd47852..cb481eccc967 100644 --- a/include/linux/evm.h +++ b/include/linux/evm.h @@ -21,45 +21,6 @@ extern enum integrity_status evm_verifyxattr(struct dentry *dentry, void *xattr_value, size_t xattr_value_len, struct integrity_iint_cache *iint); -extern int evm_inode_setattr(struct mnt_idmap *idmap, - struct dentry *dentry, struct iattr *attr); -extern void evm_inode_post_setattr(struct mnt_idmap *idmap, - struct dentry *dentry, int ia_valid); -extern int evm_inode_setxattr(struct mnt_idmap *idmap, - struct dentry *dentry, const char *name, - const void *value, size_t size, int flags); -extern void evm_inode_post_setxattr(struct dentry *dentry, - const char *xattr_name, - const void *xattr_value, - size_t xattr_value_len, - int flags); -extern int evm_inode_copy_up_xattr(const char *name); -extern int evm_inode_removexattr(struct mnt_idmap *idmap, - struct dentry *dentry, const char *xattr_name); -extern void evm_inode_post_removexattr(struct dentry *dentry, - const char *xattr_name); -static inline void evm_inode_post_remove_acl(struct mnt_idmap *idmap, - struct dentry *dentry, - const char *acl_name) -{ - evm_inode_post_removexattr(dentry, acl_name); -} -extern int evm_inode_set_acl(struct mnt_idmap *idmap, - struct dentry *dentry, const char *acl_name, - struct posix_acl *kacl); -static inline int evm_inode_remove_acl(struct mnt_idmap *idmap, - struct dentry *dentry, - const char *acl_name) -{ - return evm_inode_set_acl(idmap, dentry, acl_name, NULL); -} -static inline void evm_inode_post_set_acl(struct dentry *dentry, - const char *acl_name, - struct posix_acl *kacl) -{ - return evm_inode_post_setxattr(dentry, acl_name, NULL, 0, 0); -} - int evm_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, struct xattr *xattrs, int *xattr_count); @@ -94,80 +55,6 @@ static inline enum integrity_status evm_verifyxattr(struct dentry *dentry, } #endif -static inline int evm_inode_setattr(struct mnt_idmap *idmap, - struct dentry *dentry, struct iattr *attr) -{ - return 0; -} - -static inline void evm_inode_post_setattr(struct mnt_idmap *idmap, - struct dentry *dentry, int ia_valid) -{ - return; -} - -static inline int evm_inode_setxattr(struct mnt_idmap *idmap, - struct dentry *dentry, const char *name, - const void *value, size_t size, int flags) -{ - return 0; -} - -static inline void evm_inode_post_setxattr(struct dentry *dentry, - const char *xattr_name, - const void *xattr_value, - size_t xattr_value_len, - int flags) -{ - return; -} - -static inline int evm_inode_copy_up_xattr(const char *name) -{ - return 0; -} - -static inline int evm_inode_removexattr(struct mnt_idmap *idmap, - struct dentry *dentry, - const char *xattr_name) -{ - return 0; -} - -static inline void evm_inode_post_removexattr(struct dentry *dentry, - const char *xattr_name) -{ - return; -} - -static inline void evm_inode_post_remove_acl(struct mnt_idmap *idmap, - struct dentry *dentry, - const char *acl_name) -{ - return; -} - -static inline int evm_inode_set_acl(struct mnt_idmap *idmap, - struct dentry *dentry, const char *acl_name, - struct posix_acl *kacl) -{ - return 0; -} - -static inline int evm_inode_remove_acl(struct mnt_idmap *idmap, - struct dentry *dentry, - const char *acl_name) -{ - return 0; -} - -static inline void evm_inode_post_set_acl(struct dentry *dentry, - const char *acl_name, - struct posix_acl *kacl) -{ - return; -} - static inline int evm_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, struct xattr *xattrs, diff --git a/include/uapi/linux/lsm.h b/include/uapi/linux/lsm.h index b3b7fd699b63..33d8c9f4aa6b 100644 --- a/include/uapi/linux/lsm.h +++ b/include/uapi/linux/lsm.h @@ -63,6 +63,7 @@ struct lsm_ctx { #define LSM_ID_BPF 109 #define LSM_ID_LANDLOCK 110 #define LSM_ID_IMA 111 +#define LSM_ID_EVM 112 /* * LSM_ATTR_XXX definitions identify different LSM attributes diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index d35143179699..0a089af83a45 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -589,9 +589,9 @@ out: * userspace from writing HMAC value. Writing 'security.evm' requires * requires CAP_SYS_ADMIN privileges. */ -int evm_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, - const char *xattr_name, const void *xattr_value, - size_t xattr_value_len, int flags) +static int evm_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, + const char *xattr_name, const void *xattr_value, + size_t xattr_value_len, int flags) { const struct evm_ima_xattr_data *xattr_data = xattr_value; @@ -621,8 +621,8 @@ int evm_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, * Removing 'security.evm' requires CAP_SYS_ADMIN privileges and that * the current value is valid. */ -int evm_inode_removexattr(struct mnt_idmap *idmap, - struct dentry *dentry, const char *xattr_name) +static int evm_inode_removexattr(struct mnt_idmap *idmap, struct dentry *dentry, + const char *xattr_name) { /* Policy permits modification of the protected xattrs even though * there's no HMAC key loaded @@ -672,9 +672,11 @@ static inline int evm_inode_set_acl_change(struct mnt_idmap *idmap, * Prevent modifying posix acls causing the EVM HMAC to be re-calculated * and 'security.evm' xattr updated, unless the existing 'security.evm' is * valid. + * + * Return: zero on success, -EPERM on failure. */ -int evm_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, - const char *acl_name, struct posix_acl *kacl) +static int evm_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, + const char *acl_name, struct posix_acl *kacl) { enum integrity_status evm_status; @@ -713,6 +715,24 @@ int evm_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, return -EPERM; } +/** + * evm_inode_remove_acl - Protect the EVM extended attribute from posix acls + * @idmap: idmap of the mount + * @dentry: pointer to the affected dentry + * @acl_name: name of the posix acl + * + * Prevent removing posix acls causing the EVM HMAC to be re-calculated + * and 'security.evm' xattr updated, unless the existing 'security.evm' is + * valid. + * + * Return: zero on success, -EPERM on failure. + */ +static int evm_inode_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry, + const char *acl_name) +{ + return evm_inode_set_acl(idmap, dentry, acl_name, NULL); +} + static void evm_reset_status(struct inode *inode) { struct integrity_iint_cache *iint; @@ -761,9 +781,11 @@ bool evm_revalidate_status(const char *xattr_name) * __vfs_setxattr_noperm(). The caller of which has taken the inode's * i_mutex lock. */ -void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name, - const void *xattr_value, size_t xattr_value_len, - int flags) +static void evm_inode_post_setxattr(struct dentry *dentry, + const char *xattr_name, + const void *xattr_value, + size_t xattr_value_len, + int flags) { if (!evm_revalidate_status(xattr_name)) return; @@ -783,6 +805,21 @@ void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name, } /** + * evm_inode_post_set_acl - Update the EVM extended attribute from posix acls + * @dentry: pointer to the affected dentry + * @acl_name: name of the posix acl + * @kacl: pointer to the posix acls + * + * Update the 'security.evm' xattr with the EVM HMAC re-calculated after setting + * posix acls. + */ +static void evm_inode_post_set_acl(struct dentry *dentry, const char *acl_name, + struct posix_acl *kacl) +{ + return evm_inode_post_setxattr(dentry, acl_name, NULL, 0, 0); +} + +/** * evm_inode_post_removexattr - update 'security.evm' after removing the xattr * @dentry: pointer to the affected dentry * @xattr_name: pointer to the affected extended attribute name @@ -792,7 +829,8 @@ void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name, * No need to take the i_mutex lock here, as this function is called from * vfs_removexattr() which takes the i_mutex. */ -void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name) +static void evm_inode_post_removexattr(struct dentry *dentry, + const char *xattr_name) { if (!evm_revalidate_status(xattr_name)) return; @@ -808,6 +846,22 @@ void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name) evm_update_evmxattr(dentry, xattr_name, NULL, 0); } +/** + * evm_inode_post_remove_acl - Update the EVM extended attribute from posix acls + * @idmap: idmap of the mount + * @dentry: pointer to the affected dentry + * @acl_name: name of the posix acl + * + * Update the 'security.evm' xattr with the EVM HMAC re-calculated after + * removing posix acls. + */ +static inline void evm_inode_post_remove_acl(struct mnt_idmap *idmap, + struct dentry *dentry, + const char *acl_name) +{ + evm_inode_post_removexattr(dentry, acl_name); +} + static int evm_attr_change(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr) { @@ -831,8 +885,8 @@ static int evm_attr_change(struct mnt_idmap *idmap, * Permit update of file attributes when files have a valid EVM signature, * except in the case of them having an immutable portable signature. */ -int evm_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, - struct iattr *attr) +static int evm_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + struct iattr *attr) { unsigned int ia_valid = attr->ia_valid; enum integrity_status evm_status; @@ -883,8 +937,8 @@ int evm_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, * This function is called from notify_change(), which expects the caller * to lock the inode's i_mutex. */ -void evm_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry, - int ia_valid) +static void evm_inode_post_setattr(struct mnt_idmap *idmap, + struct dentry *dentry, int ia_valid) { if (!evm_revalidate_status(NULL)) return; @@ -901,7 +955,7 @@ void evm_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry, evm_update_evmxattr(dentry, NULL, NULL, 0); } -int evm_inode_copy_up_xattr(const char *name) +static int evm_inode_copy_up_xattr(const char *name) { if (strcmp(name, XATTR_NAME_EVM) == 0) return 1; /* Discard */ @@ -1004,4 +1058,36 @@ error: return error; } +static struct security_hook_list evm_hooks[] __ro_after_init = { + LSM_HOOK_INIT(inode_setattr, evm_inode_setattr), + LSM_HOOK_INIT(inode_post_setattr, evm_inode_post_setattr), + LSM_HOOK_INIT(inode_copy_up_xattr, evm_inode_copy_up_xattr), + LSM_HOOK_INIT(inode_setxattr, evm_inode_setxattr), + LSM_HOOK_INIT(inode_post_setxattr, evm_inode_post_setxattr), + LSM_HOOK_INIT(inode_set_acl, evm_inode_set_acl), + LSM_HOOK_INIT(inode_post_set_acl, evm_inode_post_set_acl), + LSM_HOOK_INIT(inode_remove_acl, evm_inode_remove_acl), + LSM_HOOK_INIT(inode_post_remove_acl, evm_inode_post_remove_acl), + LSM_HOOK_INIT(inode_removexattr, evm_inode_removexattr), + LSM_HOOK_INIT(inode_post_removexattr, evm_inode_post_removexattr), + LSM_HOOK_INIT(inode_init_security, evm_inode_init_security), +}; + +static const struct lsm_id evm_lsmid = { + .name = "evm", + .id = LSM_ID_EVM, +}; + +static int __init init_evm_lsm(void) +{ + security_add_hooks(evm_hooks, ARRAY_SIZE(evm_hooks), &evm_lsmid); + return 0; +} + +DEFINE_LSM(evm) = { + .name = "evm", + .init = init_evm_lsm, + .order = LSM_ORDER_LAST, +}; + late_initcall(init_evm); diff --git a/security/security.c b/security/security.c index bed659b53e59..59cb0e6cbae3 100644 --- a/security/security.c +++ b/security/security.c @@ -20,13 +20,13 @@ #include <linux/kernel_read_file.h> #include <linux/lsm_hooks.h> #include <linux/integrity.h> -#include <linux/evm.h> #include <linux/fsnotify.h> #include <linux/mman.h> #include <linux/mount.h> #include <linux/personality.h> #include <linux/backing-dev.h> #include <linux/string.h> +#include <linux/xattr.h> #include <linux/msg.h> #include <net/flow.h> @@ -50,7 +50,8 @@ (IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) ? 1 : 0) + \ (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \ (IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0) + \ - (IS_ENABLED(CONFIG_IMA) ? 1 : 0)) + (IS_ENABLED(CONFIG_IMA) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_EVM) ? 1 : 0)) /* * These are descriptions of the reasons that can be passed to the @@ -1740,10 +1741,6 @@ int security_inode_init_security(struct inode *inode, struct inode *dir, if (!xattr_count) goto out; - ret = evm_inode_init_security(inode, dir, qstr, new_xattrs, - &xattr_count); - if (ret) - goto out; ret = initxattrs(inode, new_xattrs, fs_data); out: for (; xattr_count > 0; xattr_count--) @@ -2235,14 +2232,9 @@ int security_inode_permission(struct inode *inode, int mask) int security_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr) { - int ret; - if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - ret = call_int_hook(inode_setattr, 0, idmap, dentry, attr); - if (ret) - return ret; - return evm_inode_setattr(idmap, dentry, attr); + return call_int_hook(inode_setattr, 0, idmap, dentry, attr); } EXPORT_SYMBOL_GPL(security_inode_setattr); @@ -2307,9 +2299,7 @@ int security_inode_setxattr(struct mnt_idmap *idmap, if (ret == 1) ret = cap_inode_setxattr(dentry, name, value, size, flags); - if (ret) - return ret; - return evm_inode_setxattr(idmap, dentry, name, value, size, flags); + return ret; } /** @@ -2328,15 +2318,10 @@ int security_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl) { - int ret; - if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - ret = call_int_hook(inode_set_acl, 0, idmap, dentry, acl_name, - kacl); - if (ret) - return ret; - return evm_inode_set_acl(idmap, dentry, acl_name, kacl); + return call_int_hook(inode_set_acl, 0, idmap, dentry, acl_name, + kacl); } /** @@ -2389,14 +2374,9 @@ int security_inode_get_acl(struct mnt_idmap *idmap, int security_inode_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) { - int ret; - if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return 0; - ret = call_int_hook(inode_remove_acl, 0, idmap, dentry, acl_name); - if (ret) - return ret; - return evm_inode_remove_acl(idmap, dentry, acl_name); + return call_int_hook(inode_remove_acl, 0, idmap, dentry, acl_name); } /** @@ -2432,7 +2412,6 @@ void security_inode_post_setxattr(struct dentry *dentry, const char *name, if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return; call_void_hook(inode_post_setxattr, dentry, name, value, size, flags); - evm_inode_post_setxattr(dentry, name, value, size, flags); } /** @@ -2493,9 +2472,7 @@ int security_inode_removexattr(struct mnt_idmap *idmap, ret = call_int_hook(inode_removexattr, 1, idmap, dentry, name); if (ret == 1) ret = cap_inode_removexattr(idmap, dentry, name); - if (ret) - return ret; - return evm_inode_removexattr(idmap, dentry, name); + return ret; } /** @@ -2699,7 +2676,7 @@ int security_inode_copy_up_xattr(const char *name) return rc; } - return evm_inode_copy_up_xattr(name); + return LSM_RET_DEFAULT(inode_copy_up_xattr); } EXPORT_SYMBOL(security_inode_copy_up_xattr); diff --git a/tools/testing/selftests/lsm/lsm_list_modules_test.c b/tools/testing/selftests/lsm/lsm_list_modules_test.c index 17333787cb2f..4d5d4cee2586 100644 --- a/tools/testing/selftests/lsm/lsm_list_modules_test.c +++ b/tools/testing/selftests/lsm/lsm_list_modules_test.c @@ -125,6 +125,9 @@ TEST(correct_lsm_list_modules) case LSM_ID_IMA: name = "ima"; break; + case LSM_ID_EVM: + name = "evm"; + break; default: name = "INVALID"; break; |