From 77fa6f314f0376176ef6bf3d84403e0d8b54ce28 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:30:58 +0100 Subject: security: Introduce inode_post_setattr hook In preparation for moving IMA and EVM to the LSM infrastructure, introduce the inode_post_setattr hook. At inode_setattr hook, EVM verifies the file's existing HMAC value. At inode_post_setattr, EVM re-calculates the file's HMAC based on the modified file attributes and other file metadata. Other LSMs could similarly take some action after successful file attribute change. The new hook cannot return an error and cannot cause the operation to be reverted. Signed-off-by: Roberto Sassu Reviewed-by: Stefan Berger Reviewed-by: Mimi Zohar Acked-by: Casey Schaufler Acked-by: Christian Brauner Signed-off-by: Paul Moore --- include/linux/security.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/security.h') diff --git a/include/linux/security.h b/include/linux/security.h index d0eb20f90b26..56c841aa3994 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -361,6 +361,8 @@ int security_inode_follow_link(struct dentry *dentry, struct inode *inode, int security_inode_permission(struct inode *inode, int mask); int security_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr); +void security_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + int ia_valid); int security_inode_getattr(const struct path *path); int security_inode_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, const char *name, @@ -879,6 +881,11 @@ static inline int security_inode_setattr(struct mnt_idmap *idmap, return 0; } +static inline void +security_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + int ia_valid) +{ } + static inline int security_inode_getattr(const struct path *path) { return 0; -- cgit v1.2.3 From dae52cbf5887ac51c3574648124cfe475a9b3246 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:30:59 +0100 Subject: security: Introduce inode_post_removexattr hook In preparation for moving IMA and EVM to the LSM infrastructure, introduce the inode_post_removexattr hook. At inode_removexattr hook, EVM verifies the file's existing HMAC value. At inode_post_removexattr, EVM re-calculates the file's HMAC with the passed xattr removed and other file metadata. Other LSMs could similarly take some action after successful xattr removal. The new hook cannot return an error and cannot cause the operation to be reverted. Signed-off-by: Roberto Sassu Reviewed-by: Stefan Berger Reviewed-by: Mimi Zohar Reviewed-by: Casey Schaufler Acked-by: Christian Brauner Signed-off-by: Paul Moore --- fs/xattr.c | 9 +++++---- include/linux/lsm_hook_defs.h | 2 ++ include/linux/security.h | 5 +++++ security/security.c | 14 ++++++++++++++ 4 files changed, 26 insertions(+), 4 deletions(-) (limited to 'include/linux/security.h') diff --git a/fs/xattr.c b/fs/xattr.c index 09d927603433..f891c260a971 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -552,11 +552,12 @@ __vfs_removexattr_locked(struct mnt_idmap *idmap, goto out; error = __vfs_removexattr(idmap, dentry, name); + if (error) + return error; - if (!error) { - fsnotify_xattr(dentry); - evm_inode_post_removexattr(dentry, name); - } + fsnotify_xattr(dentry); + security_inode_post_removexattr(dentry, name); + evm_inode_post_removexattr(dentry, name); out: return error; diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index a0e9e48015a4..f849f7d5bb53 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -149,6 +149,8 @@ LSM_HOOK(int, 0, inode_getxattr, struct dentry *dentry, const char *name) LSM_HOOK(int, 0, inode_listxattr, struct dentry *dentry) LSM_HOOK(int, 0, inode_removexattr, struct mnt_idmap *idmap, struct dentry *dentry, const char *name) +LSM_HOOK(void, LSM_RET_VOID, inode_post_removexattr, struct dentry *dentry, + const char *name) LSM_HOOK(int, 0, inode_set_acl, struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl) LSM_HOOK(int, 0, inode_get_acl, struct mnt_idmap *idmap, diff --git a/include/linux/security.h b/include/linux/security.h index 56c841aa3994..84ae03690340 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -380,6 +380,7 @@ 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); +void security_inode_post_removexattr(struct dentry *dentry, const char *name); 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, @@ -942,6 +943,10 @@ static inline int security_inode_removexattr(struct mnt_idmap *idmap, return cap_inode_removexattr(idmap, dentry, name); } +static inline void security_inode_post_removexattr(struct dentry *dentry, + const char *name) +{ } + 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 56527d5415e2..d77fdd3ca1bc 100644 --- a/security/security.c +++ b/security/security.c @@ -2452,6 +2452,20 @@ int security_inode_removexattr(struct mnt_idmap *idmap, return evm_inode_removexattr(idmap, dentry, name); } +/** + * security_inode_post_removexattr() - Update the inode after a removexattr op + * @dentry: file + * @name: xattr name + * + * Update the inode after a successful removexattr operation. + */ +void security_inode_post_removexattr(struct dentry *dentry, const char *name) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_removexattr, dentry, name); +} + /** * security_inode_need_killpriv() - Check if security_inode_killpriv() required * @dentry: associated dentry -- cgit v1.2.3 From 8f46ff5767b0b18329140d80d6bcabd818f42c4c Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:31:00 +0100 Subject: security: Introduce file_post_open hook In preparation to move IMA and EVM to the LSM infrastructure, introduce the file_post_open hook. Also, export security_file_post_open() for NFS. Based on policy, IMA calculates the digest of the file content and extends the TPM with the digest, verifies the file's integrity based on the digest, and/or includes the file digest in the audit log. LSMs could similarly take action depending on the file content and the access mask requested with open(). The new hook returns a value and can cause the open to be aborted. Signed-off-by: Roberto Sassu Reviewed-by: Stefan Berger Acked-by: Casey Schaufler Reviewed-by: Mimi Zohar Acked-by: Christian Brauner Signed-off-by: Paul Moore --- fs/namei.c | 2 ++ fs/nfsd/vfs.c | 6 ++++++ include/linux/lsm_hook_defs.h | 1 + include/linux/security.h | 6 ++++++ security/security.c | 17 +++++++++++++++++ 5 files changed, 32 insertions(+) (limited to 'include/linux/security.h') diff --git a/fs/namei.c b/fs/namei.c index 4e0de939fea1..ef867f1d6704 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3639,6 +3639,8 @@ static int do_open(struct nameidata *nd, error = may_open(idmap, &nd->path, acc_mode, open_flag); if (!error && !(file->f_mode & FMODE_OPENED)) error = vfs_open(&nd->path, file); + if (!error) + error = security_file_post_open(file, op->acc_mode); if (!error) error = ima_file_check(file, op->acc_mode); if (!error && do_truncate) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index b7c7a9273ea0..e44d8239545b 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -877,6 +877,12 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, goto out; } + host_err = security_file_post_open(file, may_flags); + if (host_err) { + fput(file); + goto out; + } + host_err = ima_file_check(file, may_flags); if (host_err) { fput(file); diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index f849f7d5bb53..3c84942d2818 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -191,6 +191,7 @@ LSM_HOOK(int, 0, file_send_sigiotask, struct task_struct *tsk, struct fown_struct *fown, int sig) LSM_HOOK(int, 0, file_receive, struct file *file) LSM_HOOK(int, 0, file_open, struct file *file) +LSM_HOOK(int, 0, file_post_open, struct file *file, int mask) LSM_HOOK(int, 0, file_truncate, struct file *file) LSM_HOOK(int, 0, task_alloc, struct task_struct *task, unsigned long clone_flags) diff --git a/include/linux/security.h b/include/linux/security.h index 84ae03690340..97f2212c13b6 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -411,6 +411,7 @@ int security_file_send_sigiotask(struct task_struct *tsk, struct fown_struct *fown, int sig); int security_file_receive(struct file *file); int security_file_open(struct file *file); +int security_file_post_open(struct file *file, int mask); int security_file_truncate(struct file *file); int security_task_alloc(struct task_struct *task, unsigned long clone_flags); void security_task_free(struct task_struct *task); @@ -1074,6 +1075,11 @@ static inline int security_file_open(struct file *file) return 0; } +static inline int security_file_post_open(struct file *file, int mask) +{ + return 0; +} + static inline int security_file_truncate(struct file *file) { return 0; diff --git a/security/security.c b/security/security.c index d77fdd3ca1bc..207405a84902 100644 --- a/security/security.c +++ b/security/security.c @@ -2966,6 +2966,23 @@ int security_file_open(struct file *file) return fsnotify_open_perm(file); } +/** + * security_file_post_open() - Evaluate a file after it has been opened + * @file: the file + * @mask: access mask + * + * Evaluate an opened file and the access mask requested with open(). The hook + * is useful for LSMs that require the file content to be available in order to + * make decisions. + * + * Return: Returns 0 if permission is granted. + */ +int security_file_post_open(struct file *file, int mask) +{ + return call_int_hook(file_post_open, 0, file, mask); +} +EXPORT_SYMBOL_GPL(security_file_post_open); + /** * security_file_truncate() - Check if truncating a file is allowed * @file: file -- cgit v1.2.3 From f09068b5a114ed28d2df2e82a7d30dde0145dc69 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:31:01 +0100 Subject: security: Introduce file_release hook In preparation for moving IMA and EVM to the LSM infrastructure, introduce the file_release hook. IMA calculates at file close the new digest of the file content and writes it to security.ima, so that appraisal at next file access succeeds. The new hook cannot return an error and cannot cause the operation to be reverted. Signed-off-by: Roberto Sassu Acked-by: Christian Brauner Reviewed-by: Stefan Berger Reviewed-by: Mimi Zohar Signed-off-by: Paul Moore --- fs/file_table.c | 1 + include/linux/lsm_hook_defs.h | 1 + include/linux/security.h | 4 ++++ security/security.c | 11 +++++++++++ 4 files changed, 17 insertions(+) (limited to 'include/linux/security.h') diff --git a/fs/file_table.c b/fs/file_table.c index b991f90571b4..725407f374fa 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -367,6 +367,7 @@ static void __fput(struct file *file) eventpoll_release(file); locks_remove_file(file); + security_file_release(file); ima_file_free(file); if (unlikely(file->f_flags & FASYNC)) { if (file->f_op->fasync) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 3c84942d2818..7f9e9240606e 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -173,6 +173,7 @@ LSM_HOOK(int, 0, kernfs_init_security, struct kernfs_node *kn_dir, struct kernfs_node *kn) LSM_HOOK(int, 0, file_permission, struct file *file, int mask) LSM_HOOK(int, 0, file_alloc_security, struct file *file) +LSM_HOOK(void, LSM_RET_VOID, file_release, struct file *file) LSM_HOOK(void, LSM_RET_VOID, file_free_security, struct file *file) LSM_HOOK(int, 0, file_ioctl, struct file *file, unsigned int cmd, unsigned long arg) diff --git a/include/linux/security.h b/include/linux/security.h index 97f2212c13b6..2997348afcb7 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -395,6 +395,7 @@ int security_kernfs_init_security(struct kernfs_node *kn_dir, struct kernfs_node *kn); int security_file_permission(struct file *file, int mask); int security_file_alloc(struct file *file); +void security_file_release(struct file *file); void security_file_free(struct file *file); int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg); int security_file_ioctl_compat(struct file *file, unsigned int cmd, @@ -1008,6 +1009,9 @@ static inline int security_file_alloc(struct file *file) return 0; } +static inline void security_file_release(struct file *file) +{ } + static inline void security_file_free(struct file *file) { } diff --git a/security/security.c b/security/security.c index 207405a84902..99004c44ce55 100644 --- a/security/security.c +++ b/security/security.c @@ -2718,6 +2718,17 @@ int security_file_alloc(struct file *file) return rc; } +/** + * security_file_release() - Perform actions before releasing the file ref + * @file: the file + * + * Perform actions before releasing the last reference to a file. + */ +void security_file_release(struct file *file) +{ + call_void_hook(file_release, file); +} + /** * security_file_free() - Free a file's LSM blob * @file: the file -- cgit v1.2.3 From 08abce60d63fb55f440c393f4508e99064f2fd91 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:31:02 +0100 Subject: security: Introduce path_post_mknod hook In preparation for moving IMA and EVM to the LSM infrastructure, introduce the path_post_mknod hook. IMA-appraisal requires all existing files in policy to have a file hash/signature stored in security.ima. An exception is made for empty files created by mknod, by tagging them as new files. LSMs could also take some action after files are created. The new hook cannot return an error and cannot cause the operation to be reverted. Signed-off-by: Roberto Sassu Acked-by: Casey Schaufler Reviewed-by: Mimi Zohar Acked-by: Christian Brauner Reviewed-by: Stefan Berger Signed-off-by: Paul Moore --- fs/namei.c | 5 +++++ include/linux/lsm_hook_defs.h | 2 ++ include/linux/security.h | 5 +++++ security/security.c | 14 ++++++++++++++ 4 files changed, 26 insertions(+) (limited to 'include/linux/security.h') diff --git a/fs/namei.c b/fs/namei.c index ef867f1d6704..9280aa5d60a7 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4063,6 +4063,11 @@ retry: dentry, mode, 0); break; } + + if (error) + goto out2; + + security_path_post_mknod(idmap, dentry); out2: done_path_create(&path, dentry); if (retry_estale(error, lookup_flags)) { diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 7f9e9240606e..dba5d8204dc5 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -94,6 +94,8 @@ LSM_HOOK(int, 0, path_mkdir, const struct path *dir, struct dentry *dentry, LSM_HOOK(int, 0, path_rmdir, const struct path *dir, struct dentry *dentry) LSM_HOOK(int, 0, path_mknod, const struct path *dir, struct dentry *dentry, umode_t mode, unsigned int dev) +LSM_HOOK(void, LSM_RET_VOID, path_post_mknod, struct mnt_idmap *idmap, + struct dentry *dentry) LSM_HOOK(int, 0, path_truncate, const struct path *path) LSM_HOOK(int, 0, path_symlink, const struct path *dir, struct dentry *dentry, const char *old_name) diff --git a/include/linux/security.h b/include/linux/security.h index 2997348afcb7..977dd9f7f51a 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1893,6 +1893,7 @@ int security_path_mkdir(const struct path *dir, struct dentry *dentry, umode_t m int security_path_rmdir(const struct path *dir, struct dentry *dentry); int security_path_mknod(const struct path *dir, struct dentry *dentry, umode_t mode, unsigned int dev); +void security_path_post_mknod(struct mnt_idmap *idmap, struct dentry *dentry); int security_path_truncate(const struct path *path); int security_path_symlink(const struct path *dir, struct dentry *dentry, const char *old_name); @@ -1927,6 +1928,10 @@ static inline int security_path_mknod(const struct path *dir, struct dentry *den return 0; } +static inline void security_path_post_mknod(struct mnt_idmap *idmap, + struct dentry *dentry) +{ } + static inline int security_path_truncate(const struct path *path) { return 0; diff --git a/security/security.c b/security/security.c index 99004c44ce55..ee4582e1d4d0 100644 --- a/security/security.c +++ b/security/security.c @@ -1800,6 +1800,20 @@ int security_path_mknod(const struct path *dir, struct dentry *dentry, } EXPORT_SYMBOL(security_path_mknod); +/** + * security_path_post_mknod() - Update inode security field after file creation + * @idmap: idmap of the mount + * @dentry: new file + * + * Update inode security field after a file has been created. + */ +void security_path_post_mknod(struct mnt_idmap *idmap, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(path_post_mknod, idmap, dentry); +} + /** * security_path_mkdir() - Check if creating a new directory is allowed * @dir: parent directory -- cgit v1.2.3 From a7811e34d100acf24870eb949c5ae3e49dde18b9 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:31:03 +0100 Subject: security: Introduce inode_post_create_tmpfile hook In preparation for moving IMA and EVM to the LSM infrastructure, introduce the inode_post_create_tmpfile hook. As temp files can be made persistent, treat new temp files like other new files, so that the file hash is calculated and stored in the security xattr. LSMs could also take some action after temp files have been created. The new hook cannot return an error and cannot cause the operation to be canceled. Signed-off-by: Roberto Sassu Acked-by: Casey Schaufler Reviewed-by: Mimi Zohar Acked-by: Christian Brauner Reviewed-by: Stefan Berger Signed-off-by: Paul Moore --- fs/namei.c | 1 + include/linux/lsm_hook_defs.h | 2 ++ include/linux/security.h | 6 ++++++ security/security.c | 15 +++++++++++++++ 4 files changed, 24 insertions(+) (limited to 'include/linux/security.h') diff --git a/fs/namei.c b/fs/namei.c index 9280aa5d60a7..c7ac7fdf0f25 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3705,6 +3705,7 @@ static int vfs_tmpfile(struct mnt_idmap *idmap, inode->i_state |= I_LINKABLE; spin_unlock(&inode->i_lock); } + security_inode_post_create_tmpfile(idmap, inode); ima_post_create_tmpfile(idmap, inode); return 0; } diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index dba5d8204dc5..87f60b47dfca 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -121,6 +121,8 @@ LSM_HOOK(int, 0, inode_init_security_anon, struct inode *inode, const struct qstr *name, const struct inode *context_inode) LSM_HOOK(int, 0, inode_create, struct inode *dir, struct dentry *dentry, umode_t mode) +LSM_HOOK(void, LSM_RET_VOID, inode_post_create_tmpfile, struct mnt_idmap *idmap, + struct inode *inode) LSM_HOOK(int, 0, inode_link, struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) LSM_HOOK(int, 0, inode_unlink, struct inode *dir, struct dentry *dentry) diff --git a/include/linux/security.h b/include/linux/security.h index 977dd9f7f51a..1cb604282617 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -344,6 +344,8 @@ int security_inode_init_security_anon(struct inode *inode, const struct qstr *name, const struct inode *context_inode); int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode); +void security_inode_post_create_tmpfile(struct mnt_idmap *idmap, + struct inode *inode); int security_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry); int security_inode_unlink(struct inode *dir, struct dentry *dentry); @@ -811,6 +813,10 @@ static inline int security_inode_create(struct inode *dir, return 0; } +static inline void +security_inode_post_create_tmpfile(struct mnt_idmap *idmap, struct inode *inode) +{ } + static inline int security_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) diff --git a/security/security.c b/security/security.c index ee4582e1d4d0..710db090aa8b 100644 --- a/security/security.c +++ b/security/security.c @@ -2013,6 +2013,21 @@ int security_inode_create(struct inode *dir, struct dentry *dentry, } EXPORT_SYMBOL_GPL(security_inode_create); +/** + * security_inode_post_create_tmpfile() - Update inode security of new tmpfile + * @idmap: idmap of the mount + * @inode: inode of the new tmpfile + * + * Update inode security data after a tmpfile has been created. + */ +void security_inode_post_create_tmpfile(struct mnt_idmap *idmap, + struct inode *inode) +{ + if (unlikely(IS_PRIVATE(inode))) + return; + call_void_hook(inode_post_create_tmpfile, idmap, inode); +} + /** * security_inode_link() - Check if creating a hard link is allowed * @old_dentry: existing file -- cgit v1.2.3 From 8b9d0b825c6573d654c8b8039ea79920926305c2 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:31:04 +0100 Subject: security: Introduce inode_post_set_acl hook In preparation for moving IMA and EVM to the LSM infrastructure, introduce the inode_post_set_acl hook. At inode_set_acl hook, EVM verifies the file's existing HMAC value. At inode_post_set_acl, EVM re-calculates the file's HMAC based on the modified POSIX ACL and other file metadata. Other LSMs could similarly take some action after successful POSIX ACL change. The new hook cannot return an error and cannot cause the operation to be reverted. Signed-off-by: Roberto Sassu Reviewed-by: Stefan Berger Acked-by: Casey Schaufler Reviewed-by: Mimi Zohar Acked-by: Christian Brauner Signed-off-by: Paul Moore --- fs/posix_acl.c | 1 + include/linux/lsm_hook_defs.h | 2 ++ include/linux/security.h | 7 +++++++ security/security.c | 17 +++++++++++++++++ 4 files changed, 27 insertions(+) (limited to 'include/linux/security.h') diff --git a/fs/posix_acl.c b/fs/posix_acl.c index e1af20893ebe..7556ee9f8a51 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -1137,6 +1137,7 @@ retry_deleg: error = -EIO; if (!error) { fsnotify_xattr(dentry); + security_inode_post_set_acl(dentry, acl_name, kacl); evm_inode_post_set_acl(dentry, acl_name, kacl); } diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 87f60b47dfca..b0125c99f80a 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -157,6 +157,8 @@ LSM_HOOK(void, LSM_RET_VOID, inode_post_removexattr, struct dentry *dentry, const char *name) LSM_HOOK(int, 0, inode_set_acl, struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl) +LSM_HOOK(void, LSM_RET_VOID, inode_post_set_acl, struct dentry *dentry, + const char *acl_name, struct posix_acl *kacl) 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, diff --git a/include/linux/security.h b/include/linux/security.h index 1cb604282617..c372797e1617 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -372,6 +372,8 @@ int security_inode_setxattr(struct mnt_idmap *idmap, int security_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl); +void security_inode_post_set_acl(struct dentry *dentry, const char *acl_name, + struct posix_acl *kacl); int security_inode_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name); int security_inode_remove_acl(struct mnt_idmap *idmap, @@ -915,6 +917,11 @@ static inline int security_inode_set_acl(struct mnt_idmap *idmap, return 0; } +static inline void security_inode_post_set_acl(struct dentry *dentry, + const char *acl_name, + struct posix_acl *kacl) +{ } + static inline int security_inode_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) diff --git a/security/security.c b/security/security.c index 710db090aa8b..52f62f785087 100644 --- a/security/security.c +++ b/security/security.c @@ -2350,6 +2350,23 @@ int security_inode_set_acl(struct mnt_idmap *idmap, return evm_inode_set_acl(idmap, dentry, acl_name, kacl); } +/** + * security_inode_post_set_acl() - Update inode security from posix acls set + * @dentry: file + * @acl_name: acl name + * @kacl: acl struct + * + * Update inode security data after successfully setting posix acls on @dentry. + * The posix acls in @kacl are identified by @acl_name. + */ +void security_inode_post_set_acl(struct dentry *dentry, const char *acl_name, + struct posix_acl *kacl) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_set_acl, dentry, acl_name, kacl); +} + /** * security_inode_get_acl() - Check if reading posix acls is allowed * @idmap: idmap of the mount -- cgit v1.2.3 From 2d705d8024143c272a764320c880ccd3230bb699 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:31:05 +0100 Subject: security: Introduce inode_post_remove_acl hook In preparation for moving IMA and EVM to the LSM infrastructure, introduce the inode_post_remove_acl hook. At inode_remove_acl hook, EVM verifies the file's existing HMAC value. At inode_post_remove_acl, EVM re-calculates the file's HMAC with the passed POSIX ACL removed and other file metadata. Other LSMs could similarly take some action after successful POSIX ACL removal. The new hook cannot return an error and cannot cause the operation to be reverted. Signed-off-by: Roberto Sassu Reviewed-by: Stefan Berger Acked-by: Casey Schaufler Reviewed-by: Mimi Zohar Acked-by: Christian Brauner Signed-off-by: Paul Moore --- fs/posix_acl.c | 1 + include/linux/lsm_hook_defs.h | 2 ++ include/linux/security.h | 8 ++++++++ security/security.c | 17 +++++++++++++++++ 4 files changed, 28 insertions(+) (limited to 'include/linux/security.h') diff --git a/fs/posix_acl.c b/fs/posix_acl.c index 7556ee9f8a51..0d2371240c1b 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -1246,6 +1246,7 @@ retry_deleg: error = -EIO; if (!error) { fsnotify_xattr(dentry); + security_inode_post_remove_acl(idmap, dentry, acl_name); evm_inode_post_remove_acl(idmap, dentry, acl_name); } diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index b0125c99f80a..7e414ba26333 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -163,6 +163,8 @@ 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(void, LSM_RET_VOID, inode_post_remove_acl, struct mnt_idmap *idmap, + struct dentry *dentry, const char *acl_name) 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 c372797e1617..4b03c76b91f1 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -378,6 +378,9 @@ int security_inode_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name); int security_inode_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name); +void security_inode_post_remove_acl(struct mnt_idmap *idmap, + struct dentry *dentry, + const char *acl_name); void security_inode_post_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags); int security_inode_getxattr(struct dentry *dentry, const char *name); @@ -936,6 +939,11 @@ static inline int security_inode_remove_acl(struct mnt_idmap *idmap, return 0; } +static inline void security_inode_post_remove_acl(struct mnt_idmap *idmap, + struct dentry *dentry, + const char *acl_name) +{ } + static inline void security_inode_post_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { } diff --git a/security/security.c b/security/security.c index 52f62f785087..3bed660fc950 100644 --- a/security/security.c +++ b/security/security.c @@ -2413,6 +2413,23 @@ int security_inode_remove_acl(struct mnt_idmap *idmap, return evm_inode_remove_acl(idmap, dentry, acl_name); } +/** + * security_inode_post_remove_acl() - Update inode security after rm posix acls + * @idmap: idmap of the mount + * @dentry: file + * @acl_name: acl name + * + * Update inode security data after successfully removing posix acls on + * @dentry in @idmap. The posix acls are identified by @acl_name. + */ +void security_inode_post_remove_acl(struct mnt_idmap *idmap, + struct dentry *dentry, const char *acl_name) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_remove_acl, idmap, dentry, acl_name); +} + /** * security_inode_post_setxattr() - Update the inode after a setxattr operation * @dentry: file -- cgit v1.2.3 From b8d997032a46fcf47d5bda011c0d1e87b20c08ba Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Thu, 15 Feb 2024 11:31:06 +0100 Subject: security: Introduce key_post_create_or_update hook In preparation for moving IMA and EVM to the LSM infrastructure, introduce the key_post_create_or_update hook. Depending on policy, IMA measures the key content after creation or update, so that remote verifiers are aware of the operation. Other LSMs could similarly take some action after successful key creation or update. The new hook cannot return an error and cannot cause the operation to be reverted. Signed-off-by: Roberto Sassu Reviewed-by: Stefan Berger Acked-by: Casey Schaufler Reviewed-by: Mimi Zohar Signed-off-by: Paul Moore --- include/linux/lsm_hook_defs.h | 3 +++ include/linux/security.h | 11 +++++++++++ security/keys/key.c | 7 ++++++- security/security.c | 19 +++++++++++++++++++ 4 files changed, 39 insertions(+), 1 deletion(-) (limited to 'include/linux/security.h') diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 7e414ba26333..7e4683035d34 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -405,6 +405,9 @@ LSM_HOOK(void, LSM_RET_VOID, key_free, struct key *key) LSM_HOOK(int, 0, key_permission, key_ref_t key_ref, const struct cred *cred, enum key_need_perm need_perm) LSM_HOOK(int, 0, key_getsecurity, struct key *key, char **buffer) +LSM_HOOK(void, LSM_RET_VOID, key_post_create_or_update, struct key *keyring, + struct key *key, const void *payload, size_t payload_len, + unsigned long flags, bool create) #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT diff --git a/include/linux/security.h b/include/linux/security.h index 4b03c76b91f1..8436f9abf43d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -2004,6 +2004,9 @@ void security_key_free(struct key *key); int security_key_permission(key_ref_t key_ref, const struct cred *cred, enum key_need_perm need_perm); int security_key_getsecurity(struct key *key, char **_buffer); +void security_key_post_create_or_update(struct key *keyring, struct key *key, + const void *payload, size_t payload_len, + unsigned long flags, bool create); #else @@ -2031,6 +2034,14 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) return 0; } +static inline void security_key_post_create_or_update(struct key *keyring, + struct key *key, + const void *payload, + size_t payload_len, + unsigned long flags, + bool create) +{ } + #endif #endif /* CONFIG_KEYS */ diff --git a/security/keys/key.c b/security/keys/key.c index 5b10641debd5..31a8b9408b7c 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -930,6 +930,8 @@ static key_ref_t __key_create_or_update(key_ref_t keyring_ref, goto error_link_end; } + security_key_post_create_or_update(keyring, key, payload, plen, flags, + true); ima_post_key_create_or_update(keyring, key, payload, plen, flags, true); @@ -963,10 +965,13 @@ error: key_ref = __key_update(key_ref, &prep); - if (!IS_ERR(key_ref)) + if (!IS_ERR(key_ref)) { + security_key_post_create_or_update(keyring, key, payload, plen, + flags, false); ima_post_key_create_or_update(keyring, key, payload, plen, flags, false); + } goto error_free_prep; } diff --git a/security/security.c b/security/security.c index 3bed660fc950..6c23c620e3c1 100644 --- a/security/security.c +++ b/security/security.c @@ -5453,6 +5453,25 @@ int security_key_getsecurity(struct key *key, char **buffer) *buffer = NULL; return call_int_hook(key_getsecurity, 0, key, buffer); } + +/** + * security_key_post_create_or_update() - Notification of key create or update + * @keyring: keyring to which the key is linked to + * @key: created or updated key + * @payload: data used to instantiate or update the key + * @payload_len: length of payload + * @flags: key flags + * @create: flag indicating whether the key was created or updated + * + * Notify the caller of a key creation or update. + */ +void security_key_post_create_or_update(struct key *keyring, struct key *key, + const void *payload, size_t payload_len, + unsigned long flags, bool create) +{ + call_void_hook(key_post_create_or_update, keyring, key, payload, + payload_len, flags, create); +} #endif /* CONFIG_KEYS */ #ifdef CONFIG_AUDIT -- cgit v1.2.3