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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id e2-20020a17090ab38200b0020aaa678098sm234714pjr.49.2022.10.13.15.36.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Oct 2022 15:37:00 -0700 (PDT) From: Kees Cook To: Mimi Zohar Cc: Kees Cook , Dmitry Kasatkin , Paul Moore , James Morris , "Serge E. Hallyn" , Takashi Iwai , Jonathan McDowell , Casey Schaufler , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , KP Singh , John Johansen , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH 5/9] LSM: Introduce inode_post_setattr hook Date: Thu, 13 Oct 2022 15:36:50 -0700 Message-Id: <20221013223654.659758-5-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221013222702.never.990-kees@kernel.org> References: <20221013222702.never.990-kees@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=7546; h=from:subject; bh=Xca597ImY3Tk10E6V1MSqwTfNHEUXjfa0mP2kJeVjWU=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBjSJMESltMyWfjIAxwaRChBzXRUlWazuBJOtIDnt/w 1MfQKfKJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCY0iTBAAKCRCJcvTf3G3AJvKrEA Cv4dUFIPRnCesIjZqkLeNcMzFfxbwiPE1sa41CkqiusWgCWPpw9xThOQPNFPRXFGxfmAC4WWW1s8Pg Egp8ySPdL2Z2ZoFWspeAtEgLvpvnmuRcX6fwwpY2ScnK5la6MfxFZkePaPw3Id+v98xX/AHDV1pWNb vs8AhqXnNpd3RRPq/KFMBRDfTo+AzEHouQwqd5mlYQASMCBHJoRkJEAzhRhKOAbNE8Un0qFFOJM127 f+ack2Ke7ExNavXK4FkwW2up2biDDSZlkFUKz7WtrVP+2dS2WsYjcjfUfjUvXLm2fuSJyTDpyYSnZg W1Vs4h3zeVaiPxoX+hqHJml8C9VfVSJ9TyAL9EnML3kB6wPrlAYaqYr/P4FBqsahnbuK/7vQT0Qs/F 2KI+L2CxqiFt0ts5Kh7SShJDqx8Dm/dCYydir3f9GaGEb6RkbgNa8H7dBgr9Tlen2YDZSz3/wB/V3p r9zop5w9BfLKWggfjpWH9k4e6NNtTN7hk1PuK/D+wMADD2V6v6bJl59WNYw1ImFIlznT+6PlF00Wah zmdHVen0w0epT+QxM9hC6wN3T/hhqp0jbalmg2KFioZBCZzR3xgqQpLeWgKM3lmcI7hv1IJ2iN7MQq ScwM1fPFxBDOAqCV+moVHEi1Vs8HGXUZc8I8Xrbi4Dx7pg5pfU3LkeZ3D/eg== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: IMA and EVM need to hook after setattr finishes. Introduce this hook and move IMA and EVM's open-coded stacking to use it. Cc: Mimi Zohar Cc: Dmitry Kasatkin Cc: Paul Moore Cc: James Morris Cc: "Serge E. Hallyn" Cc: Takashi Iwai Cc: Jonathan McDowell Cc: Casey Schaufler Cc: linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org Signed-off-by: Kees Cook --- fs/attr.c | 3 +-- include/linux/evm.h | 6 ------ include/linux/ima.h | 9 --------- include/linux/lsm_hook_defs.h | 3 +++ security/integrity/evm/evm_main.c | 10 +++++++++- security/integrity/ima/ima.h | 2 ++ security/integrity/ima/ima_appraise.c | 2 +- security/integrity/ima/ima_main.c | 1 + security/security.c | 8 ++++++++ 9 files changed, 25 insertions(+), 19 deletions(-) diff --git a/fs/attr.c b/fs/attr.c index 1552a5f23d6b..e5731057426b 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -423,8 +423,7 @@ int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry, if (!error) { fsnotify_change(dentry, ia_valid); - ima_inode_post_setattr(mnt_userns, dentry); - evm_inode_post_setattr(dentry, ia_valid); + security_inode_post_setattr(mnt_userns, dentry, ia_valid); } return error; diff --git a/include/linux/evm.h b/include/linux/evm.h index aa63e0b3c0a2..53f402bfb9f1 100644 --- a/include/linux/evm.h +++ b/include/linux/evm.h @@ -23,7 +23,6 @@ extern enum integrity_status evm_verifyxattr(struct dentry *dentry, struct integrity_iint_cache *iint); extern int evm_inode_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, struct iattr *attr); -extern void evm_inode_post_setattr(struct dentry *dentry, int ia_valid); extern int evm_inode_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry, const char *name, const void *value, size_t size); @@ -75,11 +74,6 @@ static inline int evm_inode_setattr(struct user_namespace *mnt_userns, return 0; } -static inline void evm_inode_post_setattr(struct dentry *dentry, int ia_valid) -{ - return; -} - static inline int evm_inode_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry, const char *name, const void *value, size_t size) diff --git a/include/linux/ima.h b/include/linux/ima.h index 9f18df366064..70180b9bd974 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -127,20 +127,11 @@ static inline void ima_post_key_create_or_update(struct key *keyring, #ifdef CONFIG_IMA_APPRAISE extern bool is_ima_appraise_enabled(void); -extern void ima_inode_post_setattr(struct user_namespace *mnt_userns, - struct dentry *dentry); #else static inline bool is_ima_appraise_enabled(void) { return 0; } - -static inline void ima_inode_post_setattr(struct user_namespace *mnt_userns, - struct dentry *dentry) -{ - return; -} - #endif /* CONFIG_IMA_APPRAISE */ #if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 806448173033..0b01473eee8a 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -135,6 +135,9 @@ LSM_HOOK(int, 0, inode_follow_link, struct dentry *dentry, struct inode *inode, bool rcu) LSM_HOOK(int, 0, inode_permission, struct inode *inode, int mask) LSM_HOOK(int, 0, inode_setattr, struct dentry *dentry, struct iattr *attr) +LSM_HOOK(void, LSM_RET_VOID, inode_post_setattr, + struct user_namespace *mnt_userns, struct dentry *dentry, + unsigned int ia_valid) LSM_HOOK(int, 0, inode_getattr, const struct path *path) LSM_HOOK(int, 0, inode_setxattr, struct user_namespace *mnt_userns, struct dentry *dentry, const char *name, const void *value, diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 1ef965089417..aca689dc0576 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -817,7 +817,9 @@ int evm_inode_setattr(struct user_namespace *mnt_userns, 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 dentry *dentry, int ia_valid) +static void evm_inode_post_setattr(struct user_namespace *mnt_userns, + struct dentry *dentry, + unsigned int ia_valid) { if (!evm_revalidate_status(NULL)) return; @@ -905,6 +907,12 @@ static int __init init_evm(void) late_initcall(init_evm); +static struct security_hook_list evm_hooks[] __lsm_ro_after_init = { + LSM_HOOK_INIT(inode_post_setattr, evm_inode_post_setattr), +}; + void __init integrity_lsm_evm_init(void) { + pr_info("Integrity LSM enabling EVM\n"); + integrity_add_lsm_hooks(evm_hooks, ARRAY_SIZE(evm_hooks)); } diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 15a369df4c00..5c95ea6e6c94 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -176,6 +176,8 @@ int ima_inode_setxattr(struct user_namespace *mnt_userns, int flags); int ima_inode_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry, const char *xattr_name); +void ima_inode_post_setattr(struct user_namespace *mnt_userns, + struct dentry *dentry, unsigned int ia_valid); #endif /* diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index ddd9df6b7dac..ccd54b50fe48 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -631,7 +631,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) * to lock the inode's i_mutex. */ void ima_inode_post_setattr(struct user_namespace *mnt_userns, - struct dentry *dentry) + struct dentry *dentry, unsigned int ia_valid) { struct inode *inode = d_backing_inode(dentry); struct integrity_iint_cache *iint; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 94379ba40b58..ffebd3236f24 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -1093,6 +1093,7 @@ static struct security_hook_list ima_hooks[] __lsm_ro_after_init = { #ifdef CONFIG_IMA_APPRAISE LSM_HOOK_INIT(inode_setxattr, ima_inode_setxattr), LSM_HOOK_INIT(inode_removexattr, ima_inode_removexattr), + LSM_HOOK_INIT(inode_post_setattr, ima_inode_post_setattr), #endif }; diff --git a/security/security.c b/security/security.c index ca731132a0e9..af42264ad3e2 100644 --- a/security/security.c +++ b/security/security.c @@ -1333,6 +1333,14 @@ int security_inode_setattr(struct user_namespace *mnt_userns, } EXPORT_SYMBOL_GPL(security_inode_setattr); +void security_inode_post_setattr(struct user_namespace *mnt_userns, + struct dentry *dentry, unsigned int ia_valid) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_setattr, mnt_userns, dentry, ia_valid); +} + int security_inode_getattr(const struct path *path) { if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry))))