diff options
| -rw-r--r-- | include/linux/lsm_hooks.h | 210 | ||||
| -rw-r--r-- | security/security.c | 334 |
2 files changed, 334 insertions, 210 deletions
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 7c58683b9288..5578a13729bd 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -32,216 +32,6 @@ /** * union security_list_options - Linux Security Module hook function list * - * Security hooks for task operations. - * - * @task_alloc: - * @task task being allocated. - * @clone_flags contains the flags indicating what should be shared. - * Handle allocation of task-related resources. - * Returns a zero on success, negative values on failure. - * @task_free: - * @task task about to be freed. - * Handle release of task-related resources. (Note that this can be called - * from interrupt context.) - * @cred_alloc_blank: - * @cred points to the credentials. - * @gfp indicates the atomicity of any memory allocations. - * Only allocate sufficient memory and attach to @cred such that - * cred_transfer() will not get ENOMEM. - * Return 0 on success, negative values on failure. - * @cred_free: - * @cred points to the credentials. - * Deallocate and clear the cred->security field in a set of credentials. - * @cred_prepare: - * @new points to the new credentials. - * @old points to the original credentials. - * @gfp indicates the atomicity of any memory allocations. - * Prepare a new set of credentials by copying the data from the old set. - * Return 0 on success, negative values on failure. - * @cred_transfer: - * @new points to the new credentials. - * @old points to the original credentials. - * Transfer data from original creds to new creds - * @cred_getsecid: - * Retrieve the security identifier of the cred structure @c - * @c contains the credentials, secid will be placed into @secid. - * In case of failure, @secid will be set to zero. - * @kernel_act_as: - * Set the credentials for a kernel service to act as (subjective context). - * @new points to the credentials to be modified. - * @secid specifies the security ID to be set. - * The current task must be the one that nominated @secid. - * Return 0 if successful. - * @kernel_create_files_as: - * Set the file creation context in a set of credentials to be the same as - * the objective context of the specified inode. - * @new points to the credentials to be modified. - * @inode points to the inode to use as a reference. - * The current task must be the one that nominated @inode. - * Return 0 if successful. - * @kernel_module_request: - * Ability to trigger the kernel to automatically upcall to userspace for - * userspace to load a kernel module with the given name. - * @kmod_name name of the module requested by the kernel. - * Return 0 if successful. - * @kernel_load_data: - * Load data provided by userspace. - * @id kernel load data identifier. - * @contents if a subsequent @kernel_post_load_data will be called. - * Return 0 if permission is granted. - * @kernel_post_load_data: - * Load data provided by a non-file source (usually userspace buffer). - * @buf pointer to buffer containing the data contents. - * @size length of the data contents. - * @id kernel load data identifier. - * @description a text description of what was loaded, @id-specific. - * Return 0 if permission is granted. - * This must be paired with a prior @kernel_load_data call that had - * @contents set to true. - * @kernel_read_file: - * Read a file specified by userspace. - * @file contains the file structure pointing to the file being read - * by the kernel. - * @id kernel read file identifier. - * @contents if a subsequent @kernel_post_read_file will be called. - * Return 0 if permission is granted. - * @kernel_post_read_file: - * Read a file specified by userspace. - * @file contains the file structure pointing to the file being read - * by the kernel. - * @buf pointer to buffer containing the file contents. - * @size length of the file contents. - * @id kernel read file identifier. - * This must be paired with a prior @kernel_read_file call that had - * @contents set to true. - * Return 0 if permission is granted. - * @task_fix_setuid: - * Update the module's state after setting one or more of the user - * identity attributes of the current process. The @flags parameter - * indicates which of the set*uid system calls invoked this hook. If - * @new is the set of credentials that will be installed. Modifications - * should be made to this rather than to @current->cred. - * @old is the set of credentials that are being replaced. - * @flags contains one of the LSM_SETID_* values. - * Return 0 on success. - * @task_fix_setgid: - * Update the module's state after setting one or more of the group - * identity attributes of the current process. The @flags parameter - * indicates which of the set*gid system calls invoked this hook. - * @new is the set of credentials that will be installed. Modifications - * should be made to this rather than to @current->cred. - * @old is the set of credentials that are being replaced. - * @flags contains one of the LSM_SETID_* values. - * Return 0 on success. - * @task_fix_setgroups: - * Update the module's state after setting the supplementary group - * identity attributes of the current process. - * @new is the set of credentials that will be installed. Modifications - * should be made to this rather than to @current->cred. - * @old is the set of credentials that are being replaced. - * Return 0 on success. - * @task_setpgid: - * Check permission before setting the process group identifier of the - * process @p to @pgid. - * @p contains the task_struct for process being modified. - * @pgid contains the new pgid. - * Return 0 if permission is granted. - * @task_getpgid: - * Check permission before getting the process group identifier of the - * process @p. - * @p contains the task_struct for the process. - * Return 0 if permission is granted. - * @task_getsid: - * Check permission before getting the session identifier of the process - * @p. - * @p contains the task_struct for the process. - * Return 0 if permission is granted. - * @current_getsecid_subj: - * Retrieve the subjective security identifier of the current task and - * return it in @secid. - * In case of failure, @secid will be set to zero. - * @task_getsecid_obj: - * Retrieve the objective security identifier of the task_struct in @p - * and return it in @secid. - * In case of failure, @secid will be set to zero. - * - * @task_setnice: - * Check permission before setting the nice value of @p to @nice. - * @p contains the task_struct of process. - * @nice contains the new nice value. - * Return 0 if permission is granted. - * @task_setioprio: - * Check permission before setting the ioprio value of @p to @ioprio. - * @p contains the task_struct of process. - * @ioprio contains the new ioprio value. - * Return 0 if permission is granted. - * @task_getioprio: - * Check permission before getting the ioprio value of @p. - * @p contains the task_struct of process. - * Return 0 if permission is granted. - * @task_prlimit: - * Check permission before getting and/or setting the resource limits of - * another task. - * @cred points to the cred structure for the current task. - * @tcred points to the cred structure for the target task. - * @flags contains the LSM_PRLIMIT_* flag bits indicating whether the - * resource limits are being read, modified, or both. - * Return 0 if permission is granted. - * @task_setrlimit: - * Check permission before setting the resource limits of process @p - * for @resource to @new_rlim. The old resource limit values can - * be examined by dereferencing (p->signal->rlim + resource). - * @p points to the task_struct for the target task's group leader. - * @resource contains the resource whose limit is being set. - * @new_rlim contains the new limits for @resource. - * Return 0 if permission is granted. - * @task_setscheduler: - * Check permission before setting scheduling policy and/or parameters of - * process @p. - * @p contains the task_struct for process. - * Return 0 if permission is granted. - * @task_getscheduler: - * Check permission before obtaining scheduling information for process - * @p. - * @p contains the task_struct for process. - * Return 0 if permission is granted. - * @task_movememory: - * Check permission before moving memory owned by process @p. - * @p contains the task_struct for process. - * Return 0 if permission is granted. - * @task_kill: - * Check permission before sending signal @sig to @p. @info can be NULL, - * the constant 1, or a pointer to a kernel_siginfo structure. If @info is 1 or - * SI_FROMKERNEL(info) is true, then the signal should be viewed as coming - * from the kernel and should typically be permitted. - * SIGIO signals are handled separately by the send_sigiotask hook in - * file_security_ops. - * @p contains the task_struct for process. - * @info contains the signal information. - * @sig contains the signal value. - * @cred contains the cred of the process where the signal originated, or - * NULL if the current task is the originator. - * Return 0 if permission is granted. - * @task_prctl: - * Check permission before performing a process control operation on the - * current process. - * @option contains the operation. - * @arg2 contains a argument. - * @arg3 contains a argument. - * @arg4 contains a argument. - * @arg5 contains a argument. - * Return -ENOSYS if no-one wanted to handle this op, any other value to - * cause prctl() to return immediately with that value. - * @task_to_inode: - * Set the security attributes for an inode based on an associated task's - * security attributes, e.g. for /proc/pid inodes. - * @p contains the task_struct for the task. - * @inode contains the inode structure for the inode. - * @userns_create: - * Check permission prior to creating a new user namespace. - * @cred points to prepared creds. - * Return 0 if successful, otherwise < 0 error code. - * * Security hooks for Netlink messaging. * * @netlink_send: diff --git a/security/security.c b/security/security.c index a527291c191d..766595a76ab4 100644 --- a/security/security.c +++ b/security/security.c @@ -2656,6 +2656,15 @@ int security_file_truncate(struct file *file) return call_int_hook(file_truncate, 0, file); } +/** + * security_task_alloc() - Allocate a task's LSM blob + * @task: the task + * @clone_flags: flags indicating what is being shared + * + * Handle allocation of task-related resources. + * + * Return: Returns a zero on success, negative values on failure. + */ int security_task_alloc(struct task_struct *task, unsigned long clone_flags) { int rc = lsm_task_alloc(task); @@ -2668,6 +2677,13 @@ int security_task_alloc(struct task_struct *task, unsigned long clone_flags) return rc; } +/** + * security_task_free() - Free a task's LSM blob and related resources + * @task: task + * + * Handle release of task-related resources. Note that this can be called from + * interrupt context. + */ void security_task_free(struct task_struct *task) { call_void_hook(task_free, task); @@ -2676,6 +2692,16 @@ void security_task_free(struct task_struct *task) task->security = NULL; } +/** + * security_cred_alloc_blank() - Allocate the min memory to allow cred_transfer + * @cred: credentials + * @gfp: gfp flags + * + * Only allocate sufficient memory and attach to @cred such that + * cred_transfer() will not get ENOMEM. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) { int rc = lsm_cred_alloc(cred, gfp); @@ -2689,6 +2715,12 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) return rc; } +/** + * security_cred_free() - Free the cred's LSM blob and associated resources + * @cred: credentials + * + * Deallocate and clear the cred->security field in a set of credentials. + */ void security_cred_free(struct cred *cred) { /* @@ -2704,6 +2736,16 @@ void security_cred_free(struct cred *cred) cred->security = NULL; } +/** + * security_prepare_creds() - Prepare a new set of credentials + * @new: new credentials + * @old: original credentials + * @gfp: gfp flags + * + * Prepare a new set of credentials by copying the data from the old set. + * + * Return: Returns 0 on success, negative values on failure. + */ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) { int rc = lsm_cred_alloc(new, gfp); @@ -2717,11 +2759,26 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) return rc; } +/** + * security_transfer_creds() - Transfer creds + * @new: target credentials + * @old: original credentials + * + * Transfer data from original creds to new creds. + */ void security_transfer_creds(struct cred *new, const struct cred *old) { call_void_hook(cred_transfer, new, old); } +/** + * security_cred_getsecid() - Get the secid from a set of credentials + * @c: credentials + * @secid: secid value + * + * Retrieve the security identifier of the cred structure @c. In case of + * failure, @secid will be set to zero. + */ void security_cred_getsecid(const struct cred *c, u32 *secid) { *secid = 0; @@ -2729,16 +2786,46 @@ void security_cred_getsecid(const struct cred *c, u32 *secid) } EXPORT_SYMBOL(security_cred_getsecid); +/** + * security_kernel_act_as() - Set the kernel credentials to act as secid + * @new: credentials + * @secid: secid + * + * Set the credentials for a kernel service to act as (subjective context). + * The current task must be the one that nominated @secid. + * + * Return: Returns 0 if successful. + */ int security_kernel_act_as(struct cred *new, u32 secid) { return call_int_hook(kernel_act_as, 0, new, secid); } +/** + * security_kernel_create_files_as() - Set file creation context using an inode + * @new: target credentials + * @inode: reference inode + * + * Set the file creation context in a set of credentials to be the same as the + * objective context of the specified inode. The current task must be the one + * that nominated @inode. + * + * Return: Returns 0 if successful. + */ int security_kernel_create_files_as(struct cred *new, struct inode *inode) { return call_int_hook(kernel_create_files_as, 0, new, inode); } +/** + * security_kernel_module_request() - Check is loading a module is allowed + * @kmod_name: module name + * + * Ability to trigger the kernel to automatically upcall to userspace for + * userspace to load a kernel module with the given name. + * + * Return: Returns 0 if successful. + */ int security_kernel_module_request(char *kmod_name) { int ret; @@ -2749,6 +2836,16 @@ int security_kernel_module_request(char *kmod_name) return integrity_kernel_module_request(kmod_name); } +/** + * security_kernel_read_file() - Read a file specified by userspace + * @file: file + * @id: file identifier + * @contents: trust if security_kernel_post_read_file() will be called + * + * Read a file specified by userspace. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_read_file(struct file *file, enum kernel_read_file_id id, bool contents) { @@ -2761,6 +2858,19 @@ int security_kernel_read_file(struct file *file, enum kernel_read_file_id id, } EXPORT_SYMBOL_GPL(security_kernel_read_file); +/** + * security_kernel_post_read_file() - Read a file specified by userspace + * @file: file + * @buf: file contents + * @size: size of file contents + * @id: file identifier + * + * Read a file specified by userspace. This must be paired with a prior call + * to security_kernel_read_file() call that indicated this hook would also be + * called, see security_kernel_read_file() for more information. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id) { @@ -2773,6 +2883,15 @@ int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, } EXPORT_SYMBOL_GPL(security_kernel_post_read_file); +/** + * security_kernel_load_data() - Load data provided by userspace + * @id: data identifier + * @contents: true if security_kernel_post_load_data() will be called + * + * Load data provided by userspace. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_load_data(enum kernel_load_data_id id, bool contents) { int ret; @@ -2784,6 +2903,20 @@ int security_kernel_load_data(enum kernel_load_data_id id, bool contents) } EXPORT_SYMBOL_GPL(security_kernel_load_data); +/** + * security_kernel_post_load_data() - Load userspace data from a non-file source + * @buf: data + * @size: size of data + * @id: data identifier + * @description: text description of data, specific to the id value + * + * Load data provided by a non-file source (usually userspace buffer). This + * must be paired with a prior security_kernel_load_data() call that indicated + * this hook would also be called, see security_kernel_load_data() for more + * information. + * + * Return: Returns 0 if permission is granted. + */ int security_kernel_post_load_data(char *buf, loff_t size, enum kernel_load_data_id id, char *description) @@ -2798,38 +2931,112 @@ int security_kernel_post_load_data(char *buf, loff_t size, } EXPORT_SYMBOL_GPL(security_kernel_post_load_data); +/** + * security_task_fix_setuid() - Update LSM with new user id attributes + * @new: updated credentials + * @old: credentials being replaced + * @flags: LSM_SETID_* flag values + * + * Update the module's state after setting one or more of the user identity + * attributes of the current process. The @flags parameter indicates which of + * the set*uid system calls invoked this hook. If @new is the set of + * credentials that will be installed. Modifications should be made to this + * rather than to @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { return call_int_hook(task_fix_setuid, 0, new, old, flags); } +/** + * security_task_fix_setgid() - Update LSM with new group id attributes + * @new: updated credentials + * @old: credentials being replaced + * @flags: LSM_SETID_* flag value + * + * Update the module's state after setting one or more of the group identity + * attributes of the current process. The @flags parameter indicates which of + * the set*gid system calls invoked this hook. @new is the set of credentials + * that will be installed. Modifications should be made to this rather than to + * @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setgid(struct cred *new, const struct cred *old, int flags) { return call_int_hook(task_fix_setgid, 0, new, old, flags); } +/** + * security_task_fix_setgroups() - Update LSM with new supplementary groups + * @new: updated credentials + * @old: credentials being replaced + * + * Update the module's state after setting the supplementary group identity + * attributes of the current process. @new is the set of credentials that will + * be installed. Modifications should be made to this rather than to + * @current->cred. + * + * Return: Returns 0 on success. + */ int security_task_fix_setgroups(struct cred *new, const struct cred *old) { return call_int_hook(task_fix_setgroups, 0, new, old); } +/** + * security_task_setpgid() - Check if setting the pgid is allowed + * @p: task being modified + * @pgid: new pgid + * + * Check permission before setting the process group identifier of the process + * @p to @pgid. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setpgid(struct task_struct *p, pid_t pgid) { return call_int_hook(task_setpgid, 0, p, pgid); } +/** + * security_task_getpgid() - Check if getting the pgid is allowed + * @p: task + * + * Check permission before getting the process group identifier of the process + * @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getpgid(struct task_struct *p) { return call_int_hook(task_getpgid, 0, p); } +/** + * security_task_getsid() - Check if getting the session id is allowed + * @p: task + * + * Check permission before getting the session identifier of the process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getsid(struct task_struct *p) { return call_int_hook(task_getsid, 0, p); } +/** + * security_current_getsecid_subj() - Get the current task's subjective secid + * @secid: secid value + * + * Retrieve the subjective security identifier of the current task and return + * it in @secid. In case of failure, @secid will be set to zero. + */ void security_current_getsecid_subj(u32 *secid) { *secid = 0; @@ -2837,6 +3044,14 @@ void security_current_getsecid_subj(u32 *secid) } EXPORT_SYMBOL(security_current_getsecid_subj); +/** + * security_task_getsecid_obj() - Get a task's objective secid + * @p: target task + * @secid: secid value + * + * Retrieve the objective security identifier of the task_struct in @p and + * return it in @secid. In case of failure, @secid will be set to zero. + */ void security_task_getsecid_obj(struct task_struct *p, u32 *secid) { *secid = 0; @@ -2844,54 +3059,157 @@ void security_task_getsecid_obj(struct task_struct *p, u32 *secid) } EXPORT_SYMBOL(security_task_getsecid_obj); +/** + * security_task_setnice() - Check if setting a task's nice value is allowed + * @p: target task + * @nice: nice value + * + * Check permission before setting the nice value of @p to @nice. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setnice(struct task_struct *p, int nice) { return call_int_hook(task_setnice, 0, p, nice); } +/** + * security_task_setioprio() - Check if setting a task's ioprio is allowed + * @p: target task + * @ioprio: ioprio value + * + * Check permission before setting the ioprio value of @p to @ioprio. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setioprio(struct task_struct *p, int ioprio) { return call_int_hook(task_setioprio, 0, p, ioprio); } +/** + * security_task_getioprio() - Check if getting a task's ioprio is allowed + * @p: task + * + * Check permission before getting the ioprio value of @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getioprio(struct task_struct *p) { return call_int_hook(task_getioprio, 0, p); } +/** + * security_task_prlimit() - Check if get/setting resources limits is allowed + * @cred: current task credentials + * @tcred: target task credentials + * @flags: LSM_PRLIMIT_* flag bits indicating a get/set/both + * + * Check permission before getting and/or setting the resource limits of + * another task. + * + * Return: Returns 0 if permission is granted. + */ int security_task_prlimit(const struct cred *cred, const struct cred *tcred, unsigned int flags) { return call_int_hook(task_prlimit, 0, cred, tcred, flags); } +/** + * security_task_setrlimit() - Check if setting a new rlimit value is allowed + * @p: target task's group leader + * @resource: resource whose limit is being set + * @new_rlim: new resource limit + * + * Check permission before setting the resource limits of process @p for + * @resource to @new_rlim. The old resource limit values can be examined by + * dereferencing (p->signal->rlim + resource). + * + * Return: Returns 0 if permission is granted. + */ int security_task_setrlimit(struct task_struct *p, unsigned int resource, struct rlimit *new_rlim) { return call_int_hook(task_setrlimit, 0, p, resource, new_rlim); } +/** + * security_task_setscheduler() - Check if setting sched policy/param is allowed + * @p: target task + * + * Check permission before setting scheduling policy and/or parameters of + * process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_setscheduler(struct task_struct *p) { return call_int_hook(task_setscheduler, 0, p); } +/** + * security_task_getscheduler() - Check if getting scheduling info is allowed + * @p: target task + * + * Check permission before obtaining scheduling information for process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_getscheduler(struct task_struct *p) { return call_int_hook(task_getscheduler, 0, p); } +/** + * security_task_movememory() - Check if moving memory is allowed + * @p: task + * + * Check permission before moving memory owned by process @p. + * + * Return: Returns 0 if permission is granted. + */ int security_task_movememory(struct task_struct *p) { return call_int_hook(task_movememory, 0, p); } +/** + * security_task_kill() - Check if sending a signal is allowed + * @p: target process + * @info: signal information + * @sig: signal value + * @cred: credentials of the signal sender, NULL if @current + * + * Check permission before sending signal @sig to @p. @info can be NULL, the + * constant 1, or a pointer to a kernel_siginfo structure. If @info is 1 or + * SI_FROMKERNEL(info) is true, then the signal should be viewed as coming from + * the kernel and should typically be permitted. SIGIO signals are handled + * separately by the send_sigiotask hook in file_security_ops. + * + * Return: Returns 0 if permission is granted. + */ int security_task_kill(struct task_struct *p, struct kernel_siginfo *info, int sig, const struct cred *cred) { return call_int_hook(task_kill, 0, p, info, sig, cred); } +/** + * security_task_prctl() - Check if a prctl op is allowed + * @option: operation + * @arg2: argument + * @arg3: argument + * @arg4: argument + * @arg5: argument + * + * Check permission before performing a process control operation on the + * current process. + * + * Return: Return -ENOSYS if no-one wanted to handle this op, any other value + * to cause prctl() to return immediately with that value. + */ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { @@ -2910,11 +3228,27 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, return rc; } +/** + * security_task_to_inode() - Set the security attributes of a task's inode + * @p: task + * @inode: inode + * + * Set the security attributes for an inode based on an associated task's + * security attributes, e.g. for /proc/pid inodes. + */ void security_task_to_inode(struct task_struct *p, struct inode *inode) { call_void_hook(task_to_inode, p, inode); } +/** + * security_create_user_ns() - Check if creating a new userns is allowed + * @cred: prepared creds + * + * Check permission prior to creating a new user namespace. + * + * Return: Returns 0 if successful, otherwise < 0 error code. + */ int security_create_user_ns(const struct cred *cred) { return call_int_hook(userns_create, 0, cred); |