/* * Simplified MAC Kernel (smack) security module * * This file contains the smack hook function implementations. * * Author: * Casey Schaufler * * Copyright (C) 2007 Casey Schaufler * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, * as published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "smack.h" /* * I hope these are the hokeyist lines of code in the module. Casey. */ #define DEVPTS_SUPER_MAGIC 0x1cd1 #define SOCKFS_MAGIC 0x534F434B #define TMPFS_MAGIC 0x01021994 /** * smk_fetch - Fetch the smack label from a file. * @ip: a pointer to the inode * @dp: a pointer to the dentry * * Returns a pointer to the master list entry for the Smack label * or NULL if there was no label to fetch. */ static char *smk_fetch(struct inode *ip, struct dentry *dp) { int rc; char in[SMK_LABELLEN]; if (ip->i_op->getxattr == NULL) return NULL; rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN); if (rc < 0) return NULL; return smk_import(in, rc); } /** * new_inode_smack - allocate an inode security blob * @smack: a pointer to the Smack label to use in the blob * * Returns the new blob or NULL if there's no memory available */ struct inode_smack *new_inode_smack(char *smack) { struct inode_smack *isp; isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL); if (isp == NULL) return NULL; isp->smk_inode = smack; isp->smk_flags = 0; mutex_init(&isp->smk_lock); return isp; } /* * LSM hooks. * We he, that is fun! */ /** * smack_ptrace_may_access - Smack approval on PTRACE_ATTACH * @ctp: child task pointer * * Returns 0 if access is OK, an error code otherwise * * Do the capability checks, and require read and write. */ static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode) { int rc; rc = cap_ptrace_may_access(ctp, mode); if (rc != 0) return rc; rc = smk_access(current->security, ctp->security, MAY_READWRITE); if (rc != 0 && capable(CAP_MAC_OVERRIDE)) return 0; return rc; } /** * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME * @ptp: parent task pointer * * Returns 0 if access is OK, an error code otherwise * * Do the capability checks, and require read and write. */ static int smack_ptrace_traceme(struct task_struct *ptp) { int rc; rc = cap_ptrace_traceme(ptp); if (rc != 0) return rc; rc = smk_access(ptp->security, current->security, MAY_READWRITE); if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE)) return 0; return rc; } /** * smack_syslog - Smack approval on syslog * @type: message type * * Require that the task has the floor label * * Returns 0 on success, error code otherwise. */ static int smack_syslog(int type) { int rc; char *sp = current->security; rc = cap_syslog(type); if (rc != 0) return rc; if (capable(CAP_MAC_OVERRIDE)) return 0; if (sp != smack_known_floor.smk_known) rc = -EACCES; return rc; } /* * Superblock Hooks. */ /** * smack_sb_alloc_security - allocate a superblock blob * @sb: the superblock getting the blob * * Returns 0 on success or -ENOMEM on error. */ static int smack_sb_alloc_security(struct super_block *sb) { struct superblock_smack *sbsp; sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); if (sbsp == NULL) return -ENOMEM; sbsp->smk_root = smack_known_floor.smk_known; sbsp->smk_default = smack_known_floor.smk_known; sbsp->smk_floor = smack_known_floor.smk_known; sbsp->smk_hat = smack_known_hat.smk_known; sbsp->smk_initialized = 0; spin_lock_init(&sbsp->smk_sblock); sb->s_security = sbsp; return 0; } /** * smack_sb_free_security - free a superblock blob * @sb: the superblock getting the blob * */ static void smack_sb_free_security(struct super_block *sb) { kfree(sb->s_security); sb->s_security = NULL; } /** * smack_sb_copy_data - copy mount options data for processing * @type: file system type * @orig: where to start * @smackopts * * Returns 0 on success or -ENOMEM on error. * * Copy the Smack specific mount options out of the mount * options list. */ static int smack_sb_copy_data(char *orig, char *smackopts) { char *cp, *commap, *otheropts, *dp; otheropts = (char *)get_zeroed_page(GFP_KERNEL); if (otheropts == NULL) return -ENOMEM; for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { if (strstr(cp, SMK_FSDEFAULT) == cp) dp = smackopts; else if (strstr(cp, SMK_FSFLOOR) == cp) dp = smackopts; else if (strstr(cp, SMK_FSHAT) == cp) dp = smackopts; else if (strstr(cp, SMK_FSROOT) == cp) dp = smackopts; else dp = otheropts; commap = strchr(cp, ','); if (commap != NULL) *commap = '\0'; if (*dp != '\0') strcat(dp, ","); strcat(dp, cp); } strcpy(orig, otheropts); free_page((unsigned long)otheropts); return 0; } /** * smack_sb_kern_mount - Smack specific mount processing * @sb: the file system superblock * @data: the smack mount options * * Returns 0 on success, an error code on failure */ static int smack_sb_kern_mount(struct super_block *sb, void *data) { struct dentry *root = sb->s_root; struct inode *inode = root->d_inode; struct superblock_smack *sp = sb->s_security; struct inode_smack *isp; char *op; char *commap; char *nsp; spin_lock(&sp->smk_sblock); if (sp->smk_initialized != 0) { spin_unlock(&sp->smk_sblock); return 0; } sp->smk_initialized = 1; spin_unlock(&sp->smk_sblock); for (op = data; op != NULL; op = commap) { commap = strchr(op, ','); if (commap != NULL) *commap++ = '\0'; if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { op += strlen(SMK_FSHAT); nsp = smk_import(op, 0); if (nsp != NULL) sp->smk_hat = nsp; } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { op += strlen(SMK_FSFLOOR); nsp = smk_import(op, 0); if (nsp != NULL) sp->smk_floor = nsp; } else if (strncmp(op, SMK_FSDEFAULT, strlen(SMK_FSDEFAULT)) == 0) { op += strlen(SMK_FSDEFAULT); nsp = smk_import(op, 0); if (nsp != NULL) sp->smk_default = nsp; } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { op += strlen(SMK_FSROOT); nsp = smk_import(op, 0); if (nsp != NULL) sp->smk_root = nsp; } } /* * Initialize the root inode. */ isp = inode->i_security; if (isp == NULL) inode->i_security = new_inode_smack(sp->smk_root); else isp->smk_inode = sp->smk_root; return 0; } /** * smack_sb_statfs - Smack check on statfs * @dentry: identifies the file system in question * * Returns 0 if current can read the floor of the filesystem, * and error code otherwise */ static int smack_sb_statfs(struct dentry *dentry) { struct superblock_smack *sbp = dentry->d_sb->s_security; return smk_curacc(sbp->smk_floor, MAY_READ); } /** * smack_sb_mount - Smack check for mounting * @dev_name: unused * @nd: mount point * @type: unused * @flags: unused * @data: unused * * Returns 0 if current can write the floor of the filesystem * being mounted on, an error code otherwise. */ static int smack_sb_mount(char *dev_name, struct path *path, char *type, unsigned long flags, void *data) { struct superblock_smack *sbp = path->mnt->mnt_sb->s_security; return smk_curacc(sbp->smk_floor, MAY_WRITE); } /** * smack_sb_umount - Smack check for unmounting * @mnt: file system to unmount * @flags: unused * * Returns 0 if current can write the floor of the filesystem * being unmounted, an error code otherwise. */ static int smack_sb_umount(struct vfsmount *mnt, int flags) { struct superblock_smack *sbp; sbp = mnt->mnt_sb->s_security; return smk_curacc(sbp->smk_floor, MAY_WRITE); } /* * Inode hooks */ /** * smack_inode_alloc_security - allocate an inode blob * @inode - the inode in need of a blob * * Returns 0 if it gets a blob, -ENOMEM otherwise */ static int smack_inode_alloc_security(struct inode *inode) { inode->i_security = new_inode_smack(current->security); if (inode->i_security == NULL) return -ENOMEM; return 0; } /** * smack_inode_free_security - free an inode blob * @inode - the inode with a blob * * Clears the blob pointer in inode */ static void smack_inode_free_security(struct inode *inode) { kfree(inode->i_security); inode->i_security = NULL; } /** * smack_inode_init_security - copy out the smack from an inode * @inode: the inode * @dir: unused * @name: where to put the attribute name * @value: where to put the attribute value * @len: where to put the length of the attribute * * Returns 0 if it all works out, -ENOMEM if there's no memory */ static int smack_inode_init_security(struct inode *inode, struct inode *dir, char **name, void **value, size_t *len) { char *isp = smk_of_inode(inode); if (name) { *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL); if (*name == NULL) return -ENOMEM; } if (value) { *value = kstrdup(isp, GFP_KERNEL); if (*value == NULL) return -ENOMEM; } if (len) *len = strlen(isp) + 1; return 0; } /** * smack_inode_link - Smack check on link * @old_dentry: the existing object * @dir: unused * @new_dentry: the new object * * Returns 0 if access is permitted, an error code otherwise */ static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) { int rc; char *isp; isp = smk_of_inode(old_dentry->d_inode); rc = smk_curacc(isp, MAY_WRITE); if (rc == 0 && new_dentry->d_inode != NULL) { isp = smk_of_inode(new_dentry->d_inode); rc = smk_curacc(isp, MAY_WRITE); } return rc; } /** * smack_inode_unlink - Smack check on inode deletion * @dir: containing directory object * @dentry: file to unlink * * Returns 0 if current can write the containing directory * and the object, error code otherwise */ static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) { struct inode *ip = dentry->d_inode; int rc; /* * You need write access to the thing you're unlinking */ rc = smk_curacc(smk_of_inode(ip), MAY_WRITE); if (rc == 0) /* * You also need write access to the containing directory */ rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); return rc; } /** * smack_inode_rmdir - Smack check on directory deletion * @dir: containing directory object * @dentry: directory to unlink * * Returns 0 if current can write the containing directory * and the directory, error code otherwise */ static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) { int rc; /* * You need write access to the thing you're removing */ rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); if (rc == 0) /* * You also need write access to the containing directory */ rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); return rc; } /** * smack_inode_rename - Smack check on rename * @old_inode: the old directory * @old_dentry: unused * @new_inode: the new directory * @new_dentry: unused * * Read and write access is required on both the old and * new directories. * * Returns 0 if access is permitted, an error code otherwise */ static int smack_inode_rename(struct inode *old_inode, struct dentry *old_dentry, struct inode *new_inode, struct dentry *new_dentry) { int rc; char *isp; isp = smk_of_inode(old_dentry->d_inode); rc = smk_curacc(isp, MAY_READWRITE); if (rc == 0 && new_dentry->d_inode != NULL) { isp = smk_of_inode(new_dentry->d_inode); rc = smk_curacc(isp, MAY_READWRITE); } return rc; } /** * smack_inode_permission - Smack version of permission() * @inode: the inode in question * @mask: the access requested * @nd: unused * * This is the important Smack hook. * * Returns 0 if access is permitted, -EACCES otherwise */ static int smack_inode_permission(struct inode *inode, int mask) { /* * No permission to check. Existence test. Yup, it's there. */ if (mask == 0) return 0; return smk_curacc(smk_of_inode(inode), mask); } /** * smack_inode_setattr - Smack check for setting attributes * @dentry: the object * @iattr: for the force flag * * Returns 0 if access is permitted, an error code otherwise */ static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) { /* * Need to allow for clearing the setuid bit. */ if (iattr->ia_valid & ATTR_FORCE) return 0; return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); } /** * smack_inode_getattr - Smack check for getting attributes * @mnt: unused * @dentry: the object * * Returns 0 if access is permitted, an error code otherwise */ static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) { return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); } /** * smack_inode_setxattr - Smack check for setting xattrs * @dentry: the object * @name: name of the attribute * @value: unused * @size: unused * @flags: unused * * This protects the Smack attribute explicitly. * * Returns 0 if access is permitted, an error code otherwise */ static int smack_inode_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { int rc = 0; if (strcmp(name, XATTR_NAME_SMACK) == 0 || strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { if (!capable(CAP_MAC_ADMIN)) rc = -EPERM; if (size == 0) rc = -EINVAL; } else rc = cap_inode_setxattr(dentry, name, value, size, flags); if (rc == 0) rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); return rc; } /** * smack_inode_post_setxattr - Apply the Smack update approved above * @dentry: object * @name: attribute name * @value: attribute value * @size: attribute size * @flags: unused * * Set the pointer in the inode blob to the entry found * in the master label list. */ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { struct inode_smack *isp; char *nsp; /* * Not SMACK */ if (strcmp(name, XATTR_NAME_SMACK)) return; if (size >= SMK_LABELLEN) return; isp = dentry->d_inode->i_security; /* * No locking is done here. This is a pointer * assignment. */ nsp = smk_import(value, size); if (nsp != NULL) isp->smk_inode = nsp; else isp->smk_inode = smack_known_invalid.smk_known; return; } /* * smack_inode_getxattr - Smack check on getxattr * @dentry: the object * @name: unused * * Returns 0 if access is permitted, an error code otherwise */ static int smack_inode_getxattr(struct dentry *dentry, const char *name) { return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); } /* * smack_inode_removexattr - Smack check on removexattr * @dentry: the object * @name: name of the attribute * * Removing the Smack attribute requires CAP_MAC_ADMIN * * Returns 0 if access is permitted, an error code otherwise */ static int smack_inode_removexattr(struct dentry *dentry, const char *name) { int rc = 0; if (strcmp(name, XATTR_NAME_SMACK) == 0 || strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { if (!capable(CAP_MAC_ADMIN)) rc = -EPERM; } else rc = cap_inode_removexattr(dentry, name); if (rc == 0) rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); return rc; } /** * smack_inode_getsecurity - get smack xattrs * @inode: the object * @name: attribute name * @buffer: where to put the result * @size: size of the buffer * @err: unused * * Returns the size of the attribute or an error code */ static int smack_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) { struct socket_smack *ssp; struct socket *sock; struct super_block *sbp; struct inode *ip = (struct inode *)inode; char *isp; int ilen; int rc = 0; if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { isp = smk_of_inode(inode); ilen = strlen(isp) + 1; *buffer = isp; return ilen; } /* * The rest of the Smack xattrs are only on sockets. */ sbp = ip->i_sb; if (sbp->s_magic != SOCKFS_MAGIC) return -EOPNOTSUPP; sock = SOCKET_I(ip); if (sock == NULL || sock->sk == NULL) return -EOPNOTSUPP; ssp = sock->sk->sk_security; if (strcmp(name, XATTR_SMACK_IPIN) == 0) isp = ssp->smk_in; else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) isp = ssp->smk_out; else return -EOPNOTSUPP; ilen = strlen(isp) + 1; if (rc == 0) { *buffer = isp; rc = ilen; } return rc; } /** * smack_inode_listsecurity - list the Smack attributes * @inode: the object * @buffer: where they go * @buffer_size: size of buffer * * Returns 0 on success, -EINVAL otherwise */ static int smack_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) { int len = strlen(XATTR_NAME_SMACK); if (buffer != NULL && len <= buffer_size) { memcpy(buffer, XATTR_NAME_SMACK, len); return len; } return -EINVAL; } /** * smack_inode_getsecid - Extract inode's security id * @inode: inode to extract the info from * @secid: where result will be saved */ static void smack_inode_getsecid(const struct inode *inode, u32 *secid) { struct inode_smack *isp = inode->i_security; *secid = smack_to_secid(isp->smk_inode); } /* * File Hooks */ /** * smack_file_permission - Smack check on file operations * @file: unused * @mask: unused * * Returns 0 * * Should access checks be done on each read or write? * UNICOS and SELinux say yes. * Trusted Solaris, Trusted Irix, and just about everyone else says no. * * I'll say no for now. Smack does not do the frequent * label changing that SELinux does. */ static int smack_file_permission(struct file *file, int mask) { return 0; } /** * smack_file_alloc_security - assign a file security blob * @file: the object * * The security blob for a file is a pointer to the master * label list, so no allocation is done. * * Returns 0 */ static int smack_file_alloc_security(struct file *file) { file->f_security = current->security; return 0; } /** * smack_file_free_security - clear a file security blob * @file: the object * * The security blob for a file is a pointer to the master * label list, so no memory is freed. */ static void smack_file_free_security(struct file *file) { file->f_security = NULL; } /** * smack_file_ioctl - Smack check on ioctls * @file: the object * @cmd: what to do * @arg: unused * * Relies heavily on the correct use of the ioctl command conventions. * * Returns 0 if allowed, error code otherwise */ static int smack_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int rc = 0; if (_IOC_DIR(cmd) & _IOC_WRITE) rc = smk_curacc(file->f_security, MAY_WRITE); if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) rc = smk_curacc(file->f_security, MAY_READ); return rc; } /** * smack_file_lock - Smack check on file locking * @file: the object * @cmd unused * * Returns 0 if current has write access, error code otherwise */ static int smack_file_lock(struct file *file, unsigned int cmd) { return smk_curacc(file->f_security, MAY_WRITE); } /** * smack_file_fcntl - Smack check on fcntl * @file: the object * @cmd: what action to check * @arg: unused * * Returns 0 if current has access, error code otherwise */ static int smack_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg) { int rc; switch (cmd) { case F_DUPFD: case F_GETFD: case F_GETFL: case F_GETLK: case F_GETOWN: case F_GETSIG: rc = smk_curacc(file->f_security, MAY_READ); break; case F_SETFD: case F_SETFL: case F_SETLK: case F_SETLKW: case F_SETOWN: case F_SETSIG: rc = smk_curacc(file->f_security, MAY_WRITE); break; default: rc = smk_curacc(file->f_security, MAY_READWRITE); } return rc; } /** * smack_file_set_fowner - set the file security blob value * @file: object in question * * Returns 0 * Further research may be required on this one. */ static int smack_file_set_fowner(struct file *file) { file->f_security = current->security; return 0; } /** * smack_file_send_sigiotask - Smack on sigio * @tsk: The target task * @fown: the object the signal come from * @signum: unused * * Allow a privileged task to get signals even if it shouldn't * * Returns 0 if a subject with the object's smack could * write to the task, an error code otherwise. */ static int smack_file_send_sigiotask(struct task_struct *tsk, struct fown_struct *fown, int signum) { struct file *file; int rc; /* * struct fown_struct is never outside the context of a struct file */ file = container_of(fown, struct file, f_owner); rc = smk_access(file->f_security, tsk->security, MAY_WRITE); if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) return 0; return rc; } /** * smack_file_receive - Smack file receive check * @file: the object * * Returns 0 if current has access, error code otherwise */ static int smack_file_receive(struct file *file) { int may = 0; /* * This code relies on bitmasks. */ if (file->f_mode & FMODE_READ) may = MAY_READ; if (file->f_mode & FMODE_WRITE) may |= MAY_WRITE; return smk_curacc(file->f_security, may); } /* * Task hooks */ /** * smack_task_alloc_security - "allocate" a task blob * @tsk: the task in need of a blob * * Smack isn't using copies of blobs. Everyone * points to an immutable list. No alloc required. * No data copy required. * * Always returns 0 */ static int smack_task_alloc_security(struct task_struct *tsk) { tsk->security = current->security; return 0; } /** * smack_task_free_security - "free" a task blob * @task: the task with the blob * * Smack isn't using copies of blobs. Everyone * points to an immutable list. The blobs never go away. * There is no leak here. */ static void smack_task_free_security(struct task_struct *task) { task->security = NULL; } /** * smack_task_setpgid - Smack check on setting pgid * @p: the task object * @pgid: unused * * Return 0 if write access is permitted */ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) { return smk_curacc(p->security, MAY_WRITE); } /** * smack_task_getpgid - Smack access check for getpgid * @p: the object task * * Returns 0 if current can read the object task, error code otherwise */ static int smack_task_getpgid(struct task_struct *p) { return smk_curacc(p->security, MAY_READ); } /** * smack_task_getsid - Smack access check for getsid * @p: the object task * * Returns 0 if current can read the object task, error code otherwise */ static int smack_task_getsid(struct task_struct *p) { return smk_curacc(p->security, MAY_READ); } /** * smack_task_getsecid - get the secid of the task * @p: the object task * @secid: where to put the result * * Sets the secid to contain a u32 version of the smack label. */ static void smack_task_getsecid(struct task_struct *p, u32 *secid) { *secid = smack_to_secid(p->security); } /** * smack_task_setnice - Smack check on setting nice * @p: the task object * @nice: unused * * Return 0 if write access is permitted */ static int smack_task_setnice(struct task_struct *p, int nice) { int rc; rc = cap_task_setnice(p, nice); if (rc == 0) rc = smk_curacc(p->security, MAY_WRITE); return rc; } /** * smack_task_setioprio - Smack check on setting ioprio * @p: the task object * @ioprio: unused * * Return 0 if write access is permitted */ static int smack_task_setioprio(struct task_struct *p, int ioprio) { int rc; rc = cap_task_setioprio(p, ioprio); if (rc == 0) rc = smk_curacc(p->security, MAY_WRITE); return rc; } /** * smack_task_getioprio - Smack check on reading ioprio * @p: the task object * * Return 0 if read access is permitted */ static int smack_task_getioprio(struct task_struct *p) { return smk_curacc(p->security, MAY_READ); } /** * smack_task_setscheduler - Smack check on setting scheduler * @p: the task object * @policy: unused * @lp: unused * * Return 0 if read access is permitted */ static int smack_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp) { int rc; rc = cap_task_setscheduler(p, policy, lp); if (rc == 0) rc = smk_curacc(p->security, MAY_WRITE); return rc; } /** * smack_task_getscheduler - Smack check on reading scheduler * @p: the task object * * Return 0 if read access is permitted */ static int smack_task_getscheduler(struct task_struct *p) { return smk_curacc(p->security, MAY_READ); } /** * smack_task_movememory - Smack check on moving memory * @p: the task object * * Return 0 if write access is permitted */ static int smack_task_movememory(struct task_struct *p) { return smk_curacc(p->security, MAY_WRITE); } /** * smack_task_kill - Smack check on signal delivery * @p: the task object * @info: unused * @sig: unused * @secid: identifies the smack to use in lieu of current's * * Return 0 if write access is permitted * * The secid behavior is an artifact of an SELinux hack * in the USB code. Someday it may go away. */ static int smack_task_kill(struct task_struct *p, struct siginfo *info, int sig, u32 secid) { /* * Sending a signal requires that the sender * can write the receiver. */ if (secid == 0) return smk_curacc(p->security, MAY_WRITE); /* * If the secid isn't 0 we're dealing with some USB IO * specific behavior. This is not clean. For one thing * we can't take privilege into account. */ return smk_access(smack_from_secid(secid), p->security, MAY_WRITE); } /** * smack_task_wait - Smack access check for waiting * @p: task to wait for * * Returns 0 if current can wait for p, error code otherwise */ static int smack_task_wait(struct task_struct *p) { int rc; rc = smk_access(current->security, p->security, MAY_WRITE); if (rc == 0) return 0; /* * Allow the operation to succeed if either task * has privilege to perform operations that might * account for the smack labels having gotten to * be different in the first place. * * This breaks the strict subject/object access * control ideal, taking the object's privilege * state into account in the decision as well as * the smack value. */ if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE)) return 0; return rc; } /** * smack_task_to_inode - copy task smack into the inode blob * @p: task to copy from * inode: inode to copy to * * Sets the smack pointer in the inode security blob */ static void smack_task_to_inode(struct task_struct *p, struct inode *inode) { struct inode_smack *isp = inode->i_security; isp->smk_inode = p->security; } /* * Socket hooks. */ /** * smack_sk_alloc_security - Allocate a socket blob * @sk: the socket * @family: unused * @priority: memory allocation priority * * Assign Smack pointers to current * * Returns 0 on success, -ENOMEM is there's no memory */ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) { char *csp = current->security; struct socket_smack *ssp; ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); if (ssp == NULL) return -ENOMEM; ssp->smk_in = csp; ssp->smk_out = csp; ssp->smk_packet[0] = '\0'; sk->sk_security = ssp; return 0; } /** * smack_sk_free_security - Free a socket blob * @sk: the socket * * Clears the blob pointer */ static void smack_sk_free_security(struct sock *sk) { kfree(sk->sk_security); } /** * smack_set_catset - convert a capset to netlabel mls categories * @catset: the Smack categories * @sap: where to put the netlabel categories * * Allocates and fills attr.mls.cat */ static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap) { unsigned char *cp; unsigned char m; int cat; int rc; int byte; if (!catset) return; sap->flags |= NETLBL_SECATTR_MLS_CAT; sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); sap->attr.mls.cat->startbit = 0; for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++) for (m = 0x80; m != 0; m >>= 1, cat++) { if ((m & *cp) == 0) continue; rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat, cat, GFP_ATOMIC); } } /** * smack_to_secattr - fill a secattr from a smack value * @smack: the smack value * @nlsp: where the result goes * * Casey says that CIPSO is good enough for now. * It can be used to effect. * It can also be abused to effect when necessary. * Appologies to the TSIG group in general and GW in particular. */ static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp) { struct smack_cipso cipso; int rc; switch (smack_net_nltype) { case NETLBL_NLTYPE_CIPSOV4: nlsp->domain = smack; nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; rc = smack_to_cipso(smack, &cipso); if (rc == 0) { nlsp->attr.mls.lvl = cipso.smk_level; smack_set_catset(cipso.smk_catset, nlsp); } else { nlsp->attr.mls.lvl = smack_cipso_direct; smack_set_catset(smack, nlsp); } break; default: break; } } /** * smack_netlabel - Set the secattr on a socket * @sk: the socket * * Convert the outbound smack value (smk_out) to a * secattr and attach it to the socket. * * Returns 0 on success or an error code */ static int smack_netlabel(struct sock *sk) { struct socket_smack *ssp; struct netlbl_lsm_secattr secattr; int rc; ssp = sk->sk_security; netlbl_secattr_init(&secattr); smack_to_secattr(ssp->smk_out, &secattr); rc = netlbl_sock_setattr(sk, &secattr); netlbl_secattr_destroy(&secattr); return rc; } /** * smack_inode_setsecurity - set smack xattrs * @inode: the object * @name: attribute name * @value: attribute value * @size: size of the attribute * @flags: unused * * Sets the named attribute in the appropriate blob * * Returns 0 on success, or an error code */ static int smack_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) { char *sp; struct inode_smack *nsp = inode->i_security; struct socket_smack *ssp; struct socket *sock; int rc = 0; if (value == NULL || size > SMK_LABELLEN || size == 0) return -EACCES; sp = smk_import(value, size); if (sp == NULL) return -EINVAL; if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { nsp->smk_inode = sp; return 0; } /* * The rest of the Smack xattrs are only on sockets. */ if (inode->i_sb->s_magic != SOCKFS_MAGIC) return -EOPNOTSUPP; sock = SOCKET_I(inode); if (sock == NULL || sock->sk == NULL) return -EOPNOTSUPP; ssp = sock->sk->sk_security; if (strcmp(name, XATTR_SMACK_IPIN) == 0) ssp->smk_in = sp; else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { ssp->smk_out = sp; rc = smack_netlabel(sock->sk); if (rc != 0) printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n", __func__, -rc); } else return -EOPNOTSUPP; return 0; } /** * smack_socket_post_create - finish socket setup * @sock: the socket * @family: protocol family * @type: unused * @protocol: unused * @kern: unused * * Sets the netlabel information on the socket * * Returns 0 on success, and error code otherwise */ static int smack_socket_post_create(struct socket *sock, int family, int type, int protocol, int kern) { if (family != PF_INET || sock->sk == NULL) return 0; /* * Set the outbound netlbl. */ return smack_netlabel(sock->sk); } /** * smack_flags_to_may - convert S_ to MAY_ values * @flags: the S_ value * * Returns the equivalent MAY_ value */ static int smack_flags_to_may(int flags) { int may = 0; if (flags & S_IRUGO) may |= MAY_READ; if (flags & S_IWUGO) may |= MAY_WRITE; if (flags & S_IXUGO) may |= MAY_EXEC; return may; } /** * smack_msg_msg_alloc_security - Set the security blob for msg_msg * @msg: the object * * Returns 0 */ static int smack_msg_msg_alloc_security(struct msg_msg *msg) { msg->security = current->security; return 0; } /** * smack_msg_msg_free_security - Clear the security blob for msg_msg * @msg: the object * * Clears the blob pointer */ static void smack_msg_msg_free_security(struct msg_msg *msg) { msg->security = NULL; } /** * smack_of_shm - the smack pointer for the shm * @shp: the object * * Returns a pointer to the smack value */ static char *smack_of_shm(struct shmid_kernel *shp) { return (char *)shp->shm_perm.security; } /** * smack_shm_alloc_security - Set the security blob for shm * @shp: the object * * Returns 0 */ static int smack_shm_alloc_security(struct shmid_kernel *shp) { struct kern_ipc_perm *isp = &shp->shm_perm; isp->security = current->security; return 0; } /** * smack_shm_free_security - Clear the security blob for shm * @shp: the object * * Clears the blob pointer */ static void smack_shm_free_security(struct shmid_kernel *shp) { struct kern_ipc_perm *isp = &shp->shm_perm; isp->security = NULL; } /** * smack_shm_associate - Smack access check for shm * @shp: the object * @shmflg: access requested * * Returns 0 if current has the requested access, error code otherwise */ static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) { char *ssp = smack_of_shm(shp); int may; may = smack_flags_to_may(shmflg); return smk_curacc(ssp, may); } /** * smack_shm_shmctl - Smack access check for shm * @shp: the object * @cmd: what it wants to do * * Returns 0 if current has the requested access, error code otherwise */ static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) { char *ssp; int may; switch (cmd) { case IPC_STAT: case SHM_STAT: may = MAY_READ; break; case IPC_SET: case SHM_LOCK: case SHM_UNLOCK: case IPC_RMID: may = MAY_READWRITE; break; case IPC_INFO: case SHM_INFO: /* * System level information. */ return 0; default: return -EINVAL; } ssp = smack_of_shm(shp); return smk_curacc(ssp, may); } /** * smack_shm_shmat - Smack access for shmat * @shp: the object * @shmaddr: unused * @shmflg: access requested * * Returns 0 if current has the requested access, error code otherwise */ static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, int shmflg) { char *ssp = smack_of_shm(shp); int may; may = smack_flags_to_may(shmflg); return smk_curacc(ssp, may); } /** * smack_of_sem - the smack pointer for the sem * @sma: the object * * Returns a pointer to the smack value */ static char *smack_of_sem(struct sem_array *sma) { return (char *)sma->sem_perm.security; } /** * smack_sem_alloc_security - Set the security blob for sem * @sma: the object * * Returns 0 */ static int smack_sem_alloc_security(struct sem_array *sma) { struct kern_ipc_perm *isp = &sma->sem_perm; isp->security = current->security; return 0; } /** * smack_sem_free_security - Clear the security blob for sem * @sma: the object * * Clears the blob pointer */ static void smack_sem_free_security(struct sem_array *sma) { struct kern_ipc_perm *isp = &sma->sem_perm; isp->security = NULL; } /** * smack_sem_associate - Smack access check for sem * @sma: the object * @semflg: access requested * * Returns 0 if current has the requested access, error code otherwise */ static int smack_sem_associate(struct sem_array *sma, int semflg) { char *ssp = smack_of_sem(sma); int may; may = smack_flags_to_may(semflg); return smk_curacc(ssp, may); } /** * smack_sem_shmctl - Smack access check for sem * @sma: the object * @cmd: what it wants to do * * Returns 0 if current has the requested access, error code otherwise */ static int smack_sem_semctl(struct sem_array *sma, int cmd) { char *ssp; int may; switch (cmd) { case GETPID: case GETNCNT: case GETZCNT: case GETVAL: case GETALL: case IPC_STAT: case SEM_STAT: may = MAY_READ; break; case SETVAL: case SETALL: case IPC_RMID: case IPC_SET: may = MAY_READWRITE; break; case IPC_INFO: case SEM_INFO: /* * System level information */ return 0; default: return -EINVAL; } ssp = smack_of_sem(sma); return smk_curacc(ssp, may); } /** * smack_sem_semop - Smack checks of semaphore operations * @sma: the object * @sops: unused * @nsops: unused * @alter: unused * * Treated as read and write in all cases. * * Returns 0 if access is allowed, error code otherwise */ static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, unsigned nsops, int alter) { char *ssp = smack_of_sem(sma); return smk_curacc(ssp, MAY_READWRITE); } /** * smack_msg_alloc_security - Set the security blob for msg * @msq: the object * * Returns 0 */ static int smack_msg_queue_alloc_security(struct msg_queue *msq) { struct kern_ipc_perm *kisp = &msq->q_perm; kisp->security = current->security; return 0; } /** * smack_msg_free_security - Clear the security blob for msg * @msq: the object * * Clears the blob pointer */ static void smack_msg_queue_free_security(struct msg_queue *msq) { struct kern_ipc_perm *kisp = &msq->q_perm; kisp->security = NULL; } /** * smack_of_msq - the smack pointer for the msq * @msq: the object * * Returns a pointer to the smack value */ static char *smack_of_msq(struct msg_queue *msq) { return (char *)msq->q_perm.security; } /** * smack_msg_queue_associate - Smack access check for msg_queue * @msq: the object * @msqflg: access requested * * Returns 0 if current has the requested access, error code otherwise */ static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) { char *msp = smack_of_msq(msq); int may; may = smack_flags_to_may(msqflg); return smk_curacc(msp, may); } /** * smack_msg_queue_msgctl - Smack access check for msg_queue * @msq: the object * @cmd: what it wants to do * * Returns 0 if current has the requested access, error code otherwise */ static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) { char *msp; int may; switch (cmd) { case IPC_STAT: case MSG_STAT: may = MAY_READ; break; case IPC_SET: case IPC_RMID: may = MAY_READWRITE; break; case IPC_INFO: case MSG_INFO: /* * System level information */ return 0; default: return -EINVAL; } msp = smack_of_msq(msq); return smk_curacc(msp, may); } /** * smack_msg_queue_msgsnd - Smack access check for msg_queue * @msq: the object * @msg: unused * @msqflg: access requested * * Returns 0 if current has the requested access, error code otherwise */ static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg) { char *msp = smack_of_msq(msq); int rc; rc = smack_flags_to_may(msqflg); return smk_curacc(msp, rc); } /** * smack_msg_queue_msgsnd - Smack access check for msg_queue * @msq: the object * @msg: unused * @target: unused * @type: unused * @mode: unused * * Returns 0 if current has read and write access, error code otherwise */ static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, struct task_struct *target, long type, int mode) { char *msp = smack_of_msq(msq); return smk_curacc(msp, MAY_READWRITE); } /** * smack_ipc_permission - Smack access for ipc_permission() * @ipp: the object permissions * @flag: access requested * * Returns 0 if current has read and write access, error code otherwise */ static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) { char *isp = ipp->security; int may; may = smack_flags_to_may(flag); return smk_curacc(isp, may); } /** * smack_ipc_getsecid - Extract smack security id * @ipcp: the object permissions * @secid: where result will be saved */ static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) { char *smack = ipp->security; *secid = smack_to_secid(smack); } /** * smack_d_instantiate - Make sure the blob is correct on an inode * @opt_dentry: unused * @inode: the object * * Set the inode's security blob if it hasn't been done already. */ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) { struct super_block *sbp; struct superblock_smack *sbsp; struct inode_smack *isp; char *csp = current->security; char *fetched; char *final; struct dentry *dp; if (inode == NULL) return; isp = inode->i_security; mutex_lock(&isp->smk_lock); /* * If the inode is already instantiated * take the quick way out */ if (isp->smk_flags & SMK_INODE_INSTANT) goto unlockandout; sbp = inode->i_sb; sbsp = sbp->s_security; /* * We're going to use the superblock default label * if there's no label on the file. */ final = sbsp->smk_default; /* * If this is the root inode the superblock * may be in the process of initialization. * If that is the case use the root value out * of the superblock. */ if (opt_dentry->d_parent == opt_dentry) { isp->smk_inode = sbsp->smk_root; isp->smk_flags |= SMK_INODE_INSTANT; goto unlockandout; } /* * This is pretty hackish. * Casey says that we shouldn't have to do * file system specific code, but it does help * with keeping it simple. */ switch (sbp->s_magic) { case SMACK_MAGIC: /* * Casey says that it's a little embarassing * that the smack file system doesn't do * extended attributes. */ final = smack_known_star.smk_known; break; case PIPEFS_MAGIC: /* * Casey says pipes are easy (?) */ final = smack_known_star.smk_known; break; case DEVPTS_SUPER_MAGIC: /* * devpts seems content with the label of the task. * Programs that change smack have to treat the * pty with respect. */ final = csp; break; case SOCKFS_MAGIC: /* * Casey says sockets get the smack of the task. */ final = csp; break; case PROC_SUPER_MAGIC: /* * Casey says procfs appears not to care. * The superblock default suffices. */ break; case TMPFS_MAGIC: /* * Device labels should come from the filesystem, * but watch out, because they're volitile, * getting recreated on every reboot. */ final = smack_known_star.smk_known; /* * No break. * * If a smack value has been set we want to use it, * but since tmpfs isn't giving us the opportunity * to set mount options simulate setting the * superblock default. */ default: /* * This isn't an understood special case. * Get the value from the xattr. * * No xattr support means, alas, no SMACK label. * Use the aforeapplied default. * It would be curious if the label of the task * does not match that assigned. */ if (inode->i_op->getxattr == NULL) break; /* * Get the dentry for xattr. */ if (opt_dentry == NULL) { dp = d_find_alias(inode); if (dp == NULL) break; } else { dp = dget(opt_dentry); if (dp == NULL) break; } fetched = smk_fetch(inode, dp); if (fetched != NULL) final = fetched; dput(dp); break; } if (final == NULL) isp->smk_inode = csp; else isp->smk_inode = final; isp->smk_flags |= SMK_INODE_INSTANT; unlockandout: mutex_unlock(&isp->smk_lock); return; } /** * smack_getprocattr - Smack process attribute access * @p: the object task * @name: the name of the attribute in /proc/.../attr * @value: where to put the result * * Places a copy of the task Smack into value * * Returns the length of the smack label or an error code */ static int smack_getprocattr(struct task_struct *p, char *name, char **value) { char *cp; int slen; if (strcmp(name, "current") != 0) return -EINVAL; cp = kstrdup(p->security, GFP_KERNEL); if (cp == NULL) return -ENOMEM; slen = strlen(cp); *value = cp; return slen; } /** * smack_setprocattr - Smack process attribute setting * @p: the object task * @name: the name of the attribute in /proc/.../attr * @value: the value to set * @size: the size of the value * * Sets the Smack value of the task. Only setting self * is permitted and only with privilege * * Returns the length of the smack label or an error code */ static int smack_setprocattr(struct task_struct *p, char *name, void *value, size_t size) { char *newsmack; /* * Changing another process' Smack value is too dangerous * and supports no sane use case. */ if (p != current) return -EPERM; if (!capable(CAP_MAC_ADMIN)) return -EPERM; if (value == NULL || size == 0 || size >= SMK_LABELLEN) return -EINVAL; if (strcmp(name, "current") != 0) return -EINVAL; newsmack = smk_import(value, size); if (newsmack == NULL) return -EINVAL; p->security = newsmack; return size; } /** * smack_unix_stream_connect - Smack access on UDS * @sock: one socket * @other: the other socket * @newsk: unused * * Return 0 if a subject with the smack of sock could access * an object with the smack of other, otherwise an error code */ static int smack_unix_stream_connect(struct socket *sock, struct socket *other, struct sock *newsk) { struct inode *sp = SOCK_INODE(sock); struct inode *op = SOCK_INODE(other); return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE); } /** * smack_unix_may_send - Smack access on UDS * @sock: one socket * @other: the other socket * * Return 0 if a subject with the smack of sock could access * an object with the smack of other, otherwise an error code */ static int smack_unix_may_send(struct socket *sock, struct socket *other) { struct inode *sp = SOCK_INODE(sock); struct inode *op = SOCK_INODE(other); return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE); } /** * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat * pair to smack * @sap: netlabel secattr * @sip: where to put the result * * Copies a smack label into sip */ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) { char smack[SMK_LABELLEN]; int pcat; if ((sap->flags & NETLBL_SECATTR_MLS_LVL) == 0) { /* * If there are flags but no level netlabel isn't * behaving the way we expect it to. * * Without guidance regarding the smack value * for the packet fall back on the network * ambient value. */ strncpy(sip, smack_net_ambient, SMK_MAXLEN); return; } /* * Get the categories, if any */ memset(smack, '\0', SMK_LABELLEN); if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0) for (pcat = -1;;) { pcat = netlbl_secattr_catmap_walk(sap->attr.mls.cat, pcat + 1); if (pcat < 0) break; smack_catset_bit(pcat, smack); } /* * If it is CIPSO using smack direct mapping * we are already done. WeeHee. */ if (sap->attr.mls.lvl == smack_cipso_direct) { memcpy(sip, smack, SMK_MAXLEN); return; } /* * Look it up in the supplied table if it is not a direct mapping. */ smack_from_cipso(sap->attr.mls.lvl, smack, sip); return; } /** * smack_socket_sock_rcv_skb - Smack packet delivery access check * @sk: socket * @skb: packet * * Returns 0 if the packet should be delivered, an error code otherwise */ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { struct netlbl_lsm_secattr secattr; struct socket_smack *ssp = sk->sk_security; char smack[SMK_LABELLEN]; int rc; if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) return 0; /* * Translate what netlabel gave us. */ memset(smack, '\0', SMK_LABELLEN); netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); if (rc == 0) smack_from_secattr(&secattr, smack); else strncpy(smack, smack_net_ambient, SMK_MAXLEN); netlbl_secattr_destroy(&secattr); /* * Receiving a packet requires that the other end * be able to write here. Read access is not required. * This is the simplist possible security model * for networking. */ rc = smk_access(smack, ssp->smk_in, MAY_WRITE); if (rc != 0) netlbl_skbuff_err(skb, rc, 0); return rc; } /** * smack_socket_getpeersec_stream - pull in packet label * @sock: the socket * @optval: user's destination * @optlen: size thereof * @len: max thereoe * * returns zero on success, an error code otherwise */ static int smack_socket_getpeersec_stream(struct socket *sock, char __user *optval, int __user *optlen, unsigned len) { struct socket_smack *ssp; int slen; int rc = 0; ssp = sock->sk->sk_security; slen = strlen(ssp->smk_packet) + 1; if (slen > len) rc = -ERANGE; else if (copy_to_user(optval, ssp->smk_packet, slen) != 0) rc = -EFAULT; if (put_user(slen, optlen) != 0) rc = -EFAULT; return rc; } /** * smack_socket_getpeersec_dgram - pull in packet label * @sock: the socket * @skb: packet data * @secid: pointer to where to put the secid of the packet * * Sets the netlabel socket state on sk from parent */ static int smack_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) { struct netlbl_lsm_secattr secattr; struct sock *sk; char smack[SMK_LABELLEN]; int family = PF_INET; u32 s; int rc; /* * Only works for families with packets. */ if (sock != NULL) { sk = sock->sk; if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) return 0; family = sk->sk_family; } /* * Translate what netlabel gave us. */ memset(smack, '\0', SMK_LABELLEN); netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, family, &secattr); if (rc == 0) smack_from_secattr(&secattr, smack); netlbl_secattr_destroy(&secattr); /* * Give up if we couldn't get anything */ if (rc != 0) return rc; s = smack_to_secid(smack); if (s == 0) return -EINVAL; *secid = s; return 0; } /** * smack_sock_graft - graft access state between two sockets * @sk: fresh sock * @parent: donor socket * * Sets the netlabel socket state on sk from parent */ static void smack_sock_graft(struct sock *sk, struct socket *parent) { struct socket_smack *ssp; int rc; if (sk == NULL) return; if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) return; ssp = sk->sk_security; ssp->smk_in = current->security; ssp->smk_out = current->security; ssp->smk_packet[0] = '\0'; rc = smack_netlabel(sk); if (rc != 0) printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n", __func__, -rc); } /** * smack_inet_conn_request - Smack access check on connect * @sk: socket involved * @skb: packet * @req: unused * * Returns 0 if a task with the packet label could write to * the socket, otherwise an error code */ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, struct request_sock *req) { struct netlbl_lsm_secattr skb_secattr; struct socket_smack *ssp = sk->sk_security; char smack[SMK_LABELLEN]; int rc; if (skb == NULL) return -EACCES; memset(smack, '\0', SMK_LABELLEN); netlbl_secattr_init(&skb_secattr); rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr); if (rc == 0) smack_from_secattr(&skb_secattr, smack); else strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN); netlbl_secattr_destroy(&skb_secattr); /* * Receiving a packet requires that the other end * be able to write here. Read access is not required. * * If the request is successful save the peer's label * so that SO_PEERCRED can report it. */ rc = smk_access(smack, ssp->smk_in, MAY_WRITE); if (rc == 0) strncpy(ssp->smk_packet, smack, SMK_MAXLEN); return rc; } /* * Key management security hooks * * Casey has not tested key support very heavily. * The permission check is most likely too restrictive. * If you care about keys please have a look. */ #ifdef CONFIG_KEYS /** * smack_key_alloc - Set the key security blob * @key: object * @tsk: the task associated with the key * @flags: unused * * No allocation required * * Returns 0 */ static int smack_key_alloc(struct key *key, struct task_struct *tsk, unsigned long flags) { key->security = tsk->security; return 0; } /** * smack_key_free - Clear the key security blob * @key: the object * * Clear the blob pointer */ static void smack_key_free(struct key *key) { key->security = NULL; } /* * smack_key_permission - Smack access on a key * @key_ref: gets to the object * @context: task involved * @perm: unused * * Return 0 if the task has read and write to the object, * an error code otherwise */ static int smack_key_permission(key_ref_t key_ref, struct task_struct *context, key_perm_t perm) { struct key *keyp; keyp = key_ref_to_ptr(key_ref); if (keyp == NULL) return -EINVAL; /* * If the key hasn't been initialized give it access so that * it may do so. */ if (keyp->security == NULL) return 0; /* * This should not occur */ if (context->security == NULL) return -EACCES; return smk_access(context->security, keyp->security, MAY_READWRITE); } #endif /* CONFIG_KEYS */ /* * Smack Audit hooks * * Audit requires a unique representation of each Smack specific * rule. This unique representation is used to distinguish the * object to be audited from remaining kernel objects and also * works as a glue between the audit hooks. * * Since repository entries are added but never deleted, we'll use * the smack_known label address related to the given audit rule as * the needed unique representation. This also better fits the smack * model where nearly everything is a label. */ #ifdef CONFIG_AUDIT /** * smack_audit_rule_init - Initialize a smack audit rule * @field: audit rule fields given from user-space (audit.h) * @op: required testing operator (=, !=, >, <, ...) * @rulestr: smack label to be audited * @vrule: pointer to save our own audit rule representation * * Prepare to audit cases where (@field @op @rulestr) is true. * The label to be audited is created if necessay. */ static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) { char **rule = (char **)vrule; *rule = NULL; if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) return -EINVAL; if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL) return -EINVAL; *rule = smk_import(rulestr, 0); return 0; } /** * smack_audit_rule_known - Distinguish Smack audit rules * @krule: rule of interest, in Audit kernel representation format * * This is used to filter Smack rules from remaining Audit ones. * If it's proved that this rule belongs to us, the * audit_rule_match hook will be called to do the final judgement. */ static int smack_audit_rule_known(struct audit_krule *krule) { struct audit_field *f; int i; for (i = 0; i < krule->field_count; i++) { f = &krule->fields[i]; if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) return 1; } return 0; } /** * smack_audit_rule_match - Audit given object ? * @secid: security id for identifying the object to test * @field: audit rule flags given from user-space * @op: required testing operator * @vrule: smack internal rule presentation * @actx: audit context associated with the check * * The core Audit hook. It's used to take the decision of * whether to audit or not to audit a given object. */ static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule, struct audit_context *actx) { char *smack; char *rule = vrule; if (!rule) { audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR, "Smack: missing rule\n"); return -ENOENT; } if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) return 0; smack = smack_from_secid(secid); /* * No need to do string comparisons. If a match occurs, * both pointers will point to the same smack_known * label. */ if (op == AUDIT_EQUAL) return (rule == smack); if (op == AUDIT_NOT_EQUAL) return (rule != smack); return 0; } /** * smack_audit_rule_free - free smack rule representation * @vrule: rule to be freed. * * No memory was allocated. */ static void smack_audit_rule_free(void *vrule) { /* No-op */ } #endif /* CONFIG_AUDIT */ /* * smack_secid_to_secctx - return the smack label for a secid * @secid: incoming integer * @secdata: destination * @seclen: how long it is * * Exists for networking code. */ static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) { char *sp = smack_from_secid(secid); *secdata = sp; *seclen = strlen(sp); return 0; } /* * smack_secctx_to_secid - return the secid for a smack label * @secdata: smack label * @seclen: how long result is * @secid: outgoing integer * * Exists for audit and networking code. */ static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) { *secid = smack_to_secid(secdata); return 0; } /* * smack_release_secctx - don't do anything. * @key_ref: unused * @context: unused * @perm: unused * * Exists to make sure nothing gets done, and properly */ static void smack_release_secctx(char *secdata, u32 seclen) { } struct security_operations smack_ops = { .name = "smack", .ptrace_may_access = smack_ptrace_may_access, .ptrace_traceme = smack_ptrace_traceme, .capget = cap_capget, .capset_check = cap_capset_check, .capset_set = cap_capset_set, .capable = cap_capable, .syslog = smack_syslog, .settime = cap_settime, .vm_enough_memory = cap_vm_enough_memory, .bprm_apply_creds = cap_bprm_apply_creds, .bprm_set_security = cap_bprm_set_security, .bprm_secureexec = cap_bprm_secureexec, .sb_alloc_security = smack_sb_alloc_security, .sb_free_security = smack_sb_free_security, .sb_copy_data = smack_sb_copy_data, .sb_kern_mount = smack_sb_kern_mount, .sb_statfs = smack_sb_statfs, .sb_mount = smack_sb_mount, .sb_umount = smack_sb_umount, .inode_alloc_security = smack_inode_alloc_security, .inode_free_security = smack_inode_free_security, .inode_init_security = smack_inode_init_security, .inode_link = smack_inode_link, .inode_unlink = smack_inode_unlink, .inode_rmdir = smack_inode_rmdir, .inode_rename = smack_inode_rename, .inode_permission = smack_inode_permission, .inode_setattr = smack_inode_setattr, .inode_getattr = smack_inode_getattr, .inode_setxattr = smack_inode_setxattr, .inode_post_setxattr = smack_inode_post_setxattr, .inode_getxattr = smack_inode_getxattr, .inode_removexattr = smack_inode_removexattr, .inode_need_killpriv = cap_inode_need_killpriv, .inode_killpriv = cap_inode_killpriv, .inode_getsecurity = smack_inode_getsecurity, .inode_setsecurity = smack_inode_setsecurity, .inode_listsecurity = smack_inode_listsecurity, .inode_getsecid = smack_inode_getsecid, .file_permission = smack_file_permission, .file_alloc_security = smack_file_alloc_security, .file_free_security = smack_file_free_security, .file_ioctl = smack_file_ioctl, .file_lock = smack_file_lock, .file_fcntl = smack_file_fcntl, .file_set_fowner = smack_file_set_fowner, .file_send_sigiotask = smack_file_send_sigiotask, .file_receive = smack_file_receive, .task_alloc_security = smack_task_alloc_security, .task_free_security = smack_task_free_security, .task_post_setuid = cap_task_post_setuid, .task_setpgid = smack_task_setpgid, .task_getpgid = smack_task_getpgid, .task_getsid = smack_task_getsid, .task_getsecid = smack_task_getsecid, .task_setnice = smack_task_setnice, .task_setioprio = smack_task_setioprio, .task_getioprio = smack_task_getioprio, .task_setscheduler = smack_task_setscheduler, .task_getscheduler = smack_task_getscheduler, .task_movememory = smack_task_movememory, .task_kill = smack_task_kill, .task_wait = smack_task_wait, .task_reparent_to_init = cap_task_reparent_to_init, .task_to_inode = smack_task_to_inode, .task_prctl = cap_task_prctl, .ipc_permission = smack_ipc_permission, .ipc_getsecid = smack_ipc_getsecid, .msg_msg_alloc_security = smack_msg_msg_alloc_security, .msg_msg_free_security = smack_msg_msg_free_security, .msg_queue_alloc_security = smack_msg_queue_alloc_security, .msg_queue_free_security = smack_msg_queue_free_security, .msg_queue_associate = smack_msg_queue_associate, .msg_queue_msgctl = smack_msg_queue_msgctl, .msg_queue_msgsnd = smack_msg_queue_msgsnd, .msg_queue_msgrcv = smack_msg_queue_msgrcv, .shm_alloc_security = smack_shm_alloc_security, .shm_free_security = smack_shm_free_security, .shm_associate = smack_shm_associate, .shm_shmctl = smack_shm_shmctl, .shm_shmat = smack_shm_shmat, .sem_alloc_security = smack_sem_alloc_security, .sem_free_security = smack_sem_free_security, .sem_associate = smack_sem_associate, .sem_semctl = smack_sem_semctl, .sem_semop = smack_sem_semop, .netlink_send = cap_netlink_send, .netlink_recv = cap_netlink_recv, .d_instantiate = smack_d_instantiate, .getprocattr = smack_getprocattr, .setprocattr = smack_setprocattr, .unix_stream_connect = smack_unix_stream_connect, .unix_may_send = smack_unix_may_send, .socket_post_create = smack_socket_post_create, .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, .socket_getpeersec_stream = smack_socket_getpeersec_stream, .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, .sk_alloc_security = smack_sk_alloc_security, .sk_free_security = smack_sk_free_security, .sock_graft = smack_sock_graft, .inet_conn_request = smack_inet_conn_request, /* key management security hooks */ #ifdef CONFIG_KEYS .key_alloc = smack_key_alloc, .key_free = smack_key_free, .key_permission = smack_key_permission, #endif /* CONFIG_KEYS */ /* Audit hooks */ #ifdef CONFIG_AUDIT .audit_rule_init = smack_audit_rule_init, .audit_rule_known = smack_audit_rule_known, .audit_rule_match = smack_audit_rule_match, .audit_rule_free = smack_audit_rule_free, #endif /* CONFIG_AUDIT */ .secid_to_secctx = smack_secid_to_secctx, .secctx_to_secid = smack_secctx_to_secid, .release_secctx = smack_release_secctx, }; /** * smack_init - initialize the smack system * * Returns 0 */ static __init int smack_init(void) { if (!security_module_enable(&smack_ops)) return 0; printk(KERN_INFO "Smack: Initializing.\n"); /* * Set the security state for the initial task. */ current->security = &smack_known_floor.smk_known; /* * Initialize locks */ spin_lock_init(&smack_known_unset.smk_cipsolock); spin_lock_init(&smack_known_huh.smk_cipsolock); spin_lock_init(&smack_known_hat.smk_cipsolock); spin_lock_init(&smack_known_star.smk_cipsolock); spin_lock_init(&smack_known_floor.smk_cipsolock); spin_lock_init(&smack_known_invalid.smk_cipsolock); /* * Register with LSM */ if (register_security(&smack_ops)) panic("smack: Unable to register with kernel.\n"); return 0; } /* * Smack requires early initialization in order to label * all processes and objects when they are created. */ security_initcall(smack_init);