diff options
| -rw-r--r-- | include/linux/lsm_hooks.h | 168 | ||||
| -rw-r--r-- | security/security.c | 231 |
2 files changed, 231 insertions, 168 deletions
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 8e006df1db56..ddbbe89a7a48 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -29,174 +29,6 @@ #include <linux/init.h> #include <linux/rculist.h> -/** - * union security_list_options - Linux Security Module hook function list - * - * @ptrace_access_check: - * Check permission before allowing the current process to trace the - * @child process. - * Security modules may also want to perform a process tracing check - * during an execve in the set_security or apply_creds hooks of - * tracing check during an execve in the bprm_set_creds hook of - * binprm_security_ops if the process is being traced and its security - * attributes would be changed by the execve. - * @child contains the task_struct structure for the target process. - * @mode contains the PTRACE_MODE flags indicating the form of access. - * Return 0 if permission is granted. - * @ptrace_traceme: - * Check that the @parent process has sufficient permission to trace the - * current process before allowing the current process to present itself - * to the @parent process for tracing. - * @parent contains the task_struct structure for debugger process. - * Return 0 if permission is granted. - * @capget: - * Get the @effective, @inheritable, and @permitted capability sets for - * the @target process. The hook may also perform permission checking to - * determine if the current process is allowed to see the capability sets - * of the @target process. - * @target contains the task_struct structure for target process. - * @effective contains the effective capability set. - * @inheritable contains the inheritable capability set. - * @permitted contains the permitted capability set. - * Return 0 if the capability sets were successfully obtained. - * @capset: - * Set the @effective, @inheritable, and @permitted capability sets for - * the current process. - * @new contains the new credentials structure for target process. - * @old contains the current credentials structure for target process. - * @effective contains the effective capability set. - * @inheritable contains the inheritable capability set. - * @permitted contains the permitted capability set. - * Return 0 and update @new if permission is granted. - * @capable: - * Check whether the @tsk process has the @cap capability in the indicated - * credentials. - * @cred contains the credentials to use. - * @ns contains the user namespace we want the capability in. - * @cap contains the capability <include/linux/capability.h>. - * @opts contains options for the capable check <include/linux/security.h>. - * Return 0 if the capability is granted for @tsk. - * @quotactl: - * Check whether the quotactl syscall is allowed for this @sb. - * Return 0 if permission is granted. - * @quota_on: - * Check whether QUOTAON is allowed for this @dentry. - * Return 0 if permission is granted. - * @syslog: - * Check permission before accessing the kernel message ring or changing - * logging to the console. - * See the syslog(2) manual page for an explanation of the @type values. - * @type contains the SYSLOG_ACTION_* constant from - * <include/linux/syslog.h>. - * Return 0 if permission is granted. - * @settime: - * Check permission to change the system time. - * struct timespec64 is defined in <include/linux/time64.h> and timezone - * is defined in <include/linux/time.h> - * @ts contains new time. - * @tz contains new timezone. - * Return 0 if permission is granted. - * @vm_enough_memory: - * Check permissions for allocating a new virtual mapping. - * @mm contains the mm struct it is being added to. - * @pages contains the number of pages. - * Return 0 if permission is granted by the LSM infrastructure to the - * caller. If all LSMs return a positive value, __vm_enough_memory() will - * be called with cap_sys_admin set. If at least one LSM returns 0 or - * negative, __vm_enough_memory() will be called with cap_sys_admin - * cleared. - * - * @ismaclabel: - * Check if the extended attribute specified by @name - * represents a MAC label. Returns 1 if name is a MAC - * attribute otherwise returns 0. - * @name full extended attribute name to check against - * LSM as a MAC label. - * - * @secid_to_secctx: - * Convert secid to security context. If secdata is NULL the length of - * the result will be returned in seclen, but no secdata will be returned. - * This does mean that the length could change between calls to check the - * length and the next call which actually allocates and returns the - * secdata. - * @secid contains the security ID. - * @secdata contains the pointer that stores the converted security - * context. - * @seclen pointer which contains the length of the data. - * Return 0 on success, error on failure. - * @secctx_to_secid: - * Convert security context to secid. - * @secid contains the pointer to the generated security ID. - * @secdata contains the security context. - * Return 0 on success, error on failure. - * - * @release_secctx: - * Release the security context. - * @secdata contains the security context. - * @seclen contains the length of the security context. - * - * @inode_invalidate_secctx: - * Notify the security module that it must revalidate the security context - * of an inode. - * - * @inode_notifysecctx: - * Notify the security module of what the security context of an inode - * should be. Initializes the incore security context managed by the - * security module for this inode. Example usage: NFS client invokes - * this hook to initialize the security context in its incore inode to the - * value provided by the server for the file when the server returned the - * file's attributes to the client. - * Must be called with inode->i_mutex locked. - * @inode we wish to set the security context of. - * @ctx contains the string which we wish to set in the inode. - * @ctxlen contains the length of @ctx. - * Return 0 on success, error on failure. - * - * @inode_setsecctx: - * Change the security context of an inode. Updates the - * incore security context managed by the security module and invokes the - * fs code as needed (via __vfs_setxattr_noperm) to update any backing - * xattrs that represent the context. Example usage: NFS server invokes - * this hook to change the security context in its incore inode and on the - * backing filesystem to a value provided by the client on a SETATTR - * operation. - * Must be called with inode->i_mutex locked. - * @dentry contains the inode we wish to set the security context of. - * @ctx contains the string which we wish to set in the inode. - * @ctxlen contains the length of @ctx. - * Return 0 on success, error on failure. - * - * @inode_getsecctx: - * On success, returns 0 and fills out @ctx and @ctxlen with the security - * context for the given @inode. - * @inode we wish to get the security context of. - * @ctx is a pointer in which to place the allocated security context. - * @ctxlen points to the place to put the length of @ctx. - * Return 0 on success, error on failure. - * - * Security hooks for the general notification queue: - * - * @post_notification: - * Check to see if a watch notification can be posted to a particular - * queue. - * @w_cred: The credentials of the whoever set the watch. - * @cred: The event-triggerer's credentials. - * @n: The notification being posted. - * Return 0 if permission is granted. - * - * @watch_key: - * Check to see if a process is allowed to watch for event notifications - * from a key or keyring. - * @key: The key to watch. - * Return 0 if permission is granted. - * - * @locked_down: - * Determine whether a kernel feature that potentially enables arbitrary - * code execution in kernel space should be permitted. - * @what: kernel feature being accessed. - * Return 0 if permission is granted. - * - */ union security_list_options { #define LSM_HOOK(RET, DEFAULT, NAME, ...) RET (*NAME)(__VA_ARGS__); #include "lsm_hook_defs.h" diff --git a/security/security.c b/security/security.c index af1db3fa7cd0..190a701fe444 100644 --- a/security/security.c +++ b/security/security.c @@ -838,16 +838,54 @@ int security_binder_transfer_file(const struct cred *from, return call_int_hook(binder_transfer_file, 0, from, to, file); } +/** + * security_ptrace_access_check() - Check if tracing is allowed + * @child: target process + * @mode: PTRACE_MODE flags + * + * Check permission before allowing the current process to trace the @child + * process. Security modules may also want to perform a process tracing check + * during an execve in the set_security or apply_creds hooks of tracing check + * during an execve in the bprm_set_creds hook of binprm_security_ops if the + * process is being traced and its security attributes would be changed by the + * execve. + * + * Return: Returns 0 if permission is granted. + */ int security_ptrace_access_check(struct task_struct *child, unsigned int mode) { return call_int_hook(ptrace_access_check, 0, child, mode); } +/** + * security_ptrace_traceme() - Check if tracing is allowed + * @parent: tracing process + * + * Check that the @parent process has sufficient permission to trace the + * current process before allowing the current process to present itself to the + * @parent process for tracing. + * + * Return: Returns 0 if permission is granted. + */ int security_ptrace_traceme(struct task_struct *parent) { return call_int_hook(ptrace_traceme, 0, parent); } +/** + * security_capget() - Get the capability sets for a process + * @target: target process + * @effective: effective capability set + * @inheritable: inheritable capability set + * @permitted: permitted capability set + * + * Get the @effective, @inheritable, and @permitted capability sets for the + * @target process. The hook may also perform permission checking to determine + * if the current process is allowed to see the capability sets of the @target + * process. + * + * Return: Returns 0 if the capability sets were successfully obtained. + */ int security_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, @@ -857,6 +895,19 @@ int security_capget(struct task_struct *target, effective, inheritable, permitted); } +/** + * security_capset() - Set the capability sets for a process + * @new: new credentials for the target process + * @old: current credentials of the target process + * @effective: effective capability set + * @inheritable: inheritable capability set + * @permitted: permitted capability set + * + * Set the @effective, @inheritable, and @permitted capability sets for the + * current process. + * + * Return: Returns 0 and update @new if permission is granted. + */ int security_capset(struct cred *new, const struct cred *old, const kernel_cap_t *effective, const kernel_cap_t *inheritable, @@ -866,6 +917,19 @@ int security_capset(struct cred *new, const struct cred *old, effective, inheritable, permitted); } +/** + * security_capable() - Check if a process has the necessary capability + * @cred: credentials to examine + * @ns: user namespace + * @cap: capability requested + * @opts: capability check options + * + * Check whether the @tsk process has the @cap capability in the indicated + * credentials. @cap contains the capability <include/linux/capability.h>. + * @opts contains options for the capable check <include/linux/security.h>. + * + * Return: Returns 0 if the capability is granted. + */ int security_capable(const struct cred *cred, struct user_namespace *ns, int cap, @@ -874,26 +938,78 @@ int security_capable(const struct cred *cred, return call_int_hook(capable, 0, cred, ns, cap, opts); } +/** + * security_quotactl() - Check if a quotactl() syscall is allowed for this fs + * @cmds: commands + * @type: type + * @id: id + * @sb: filesystem + * + * Check whether the quotactl syscall is allowed for this @sb. + * + * Return: Returns 0 if permission is granted. + */ int security_quotactl(int cmds, int type, int id, struct super_block *sb) { return call_int_hook(quotactl, 0, cmds, type, id, sb); } +/** + * security_quota_on() - Check if QUOTAON is allowed for a dentry + * @dentry: dentry + * + * Check whether QUOTAON is allowed for @dentry. + * + * Return: Returns 0 if permission is granted. + */ int security_quota_on(struct dentry *dentry) { return call_int_hook(quota_on, 0, dentry); } +/** + * security_syslog() - Check if accessing the kernel message ring is allowed + * @type: SYSLOG_ACTION_* type + * + * Check permission before accessing the kernel message ring or changing + * logging to the console. See the syslog(2) manual page for an explanation of + * the @type values. + * + * Return: Return 0 if permission is granted. + */ int security_syslog(int type) { return call_int_hook(syslog, 0, type); } +/** + * security_settime64() - Check if changing the system time is allowed + * @ts: new time + * @tz: timezone + * + * Check permission to change the system time, struct timespec64 is defined in + * <include/linux/time64.h> and timezone is defined in <include/linux/time.h>. + * + * Return: Returns 0 if permission is granted. + */ int security_settime64(const struct timespec64 *ts, const struct timezone *tz) { return call_int_hook(settime, 0, ts, tz); } +/** + * security_vm_enough_memory_mm() - Check if allocating a new mem map is allowed + * @mm: mm struct + * @pages: number of pages + * + * Check permissions for allocating a new virtual mapping. If all LSMs return + * a positive value, __vm_enough_memory() will be called with cap_sys_admin + * set. If at least one LSM returns 0 or negative, __vm_enough_memory() will be + * called with cap_sys_admin cleared. + * + * Return: Returns 0 if permission is granted by the LSM infrastructure to the + * caller. + */ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) { struct security_hook_list *hp; @@ -3703,12 +3819,33 @@ int security_netlink_send(struct sock *sk, struct sk_buff *skb) return call_int_hook(netlink_send, 0, sk, skb); } +/** + * security_ismaclabel() - Check is the named attribute is a MAC label + * @name: full extended attribute name + * + * Check if the extended attribute specified by @name represents a MAC label. + * + * Return: Returns 1 if name is a MAC attribute otherwise returns 0. + */ int security_ismaclabel(const char *name) { return call_int_hook(ismaclabel, 0, name); } EXPORT_SYMBOL(security_ismaclabel); +/** + * security_secid_to_secctx() - Convert a secid to a secctx + * @secid: secid + * @secdata: secctx + * @seclen: secctx length + * + * Convert secid to security context. If @secdata is NULL the length of the + * result will be returned in @seclen, but no @secdata will be returned. This + * does mean that the length could change between calls to check the length and + * the next call which actually allocates and returns the @secdata. + * + * Return: Return 0 on success, error on failure. + */ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) { struct security_hook_list *hp; @@ -3728,6 +3865,16 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) } EXPORT_SYMBOL(security_secid_to_secctx); +/** + * security_secctx_to_secid() - Convert a secctx to a secid + * @secdata: secctx + * @seclen: length of secctx + * @secid: secid + * + * Convert security context to secid. + * + * Return: Returns 0 on success, error on failure. + */ int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) { *secid = 0; @@ -3735,30 +3882,86 @@ int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) } EXPORT_SYMBOL(security_secctx_to_secid); +/** + * security_release_secctx() - Free a secctx buffer + * @secdata: secctx + * @seclen: length of secctx + * + * Release the security context. + */ void security_release_secctx(char *secdata, u32 seclen) { call_void_hook(release_secctx, secdata, seclen); } EXPORT_SYMBOL(security_release_secctx); +/** + * security_inode_invalidate_secctx() - Invalidate an inode's security label + * @inode: inode + * + * Notify the security module that it must revalidate the security context of + * an inode. + */ void security_inode_invalidate_secctx(struct inode *inode) { call_void_hook(inode_invalidate_secctx, inode); } EXPORT_SYMBOL(security_inode_invalidate_secctx); +/** + * security_inode_notifysecctx() - Nofify the LSM of an inode's security label + * @inode: inode + * @ctx: secctx + * @ctxlen: length of secctx + * + * Notify the security module of what the security context of an inode should + * be. Initializes the incore security context managed by the security module + * for this inode. Example usage: NFS client invokes this hook to initialize + * the security context in its incore inode to the value provided by the server + * for the file when the server returned the file's attributes to the client. + * Must be called with inode->i_mutex locked. + * + * Return: Returns 0 on success, error on failure. + */ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) { return call_int_hook(inode_notifysecctx, 0, inode, ctx, ctxlen); } EXPORT_SYMBOL(security_inode_notifysecctx); +/** + * security_inode_setsecctx() - Change the security label of an inode + * @dentry: inode + * @ctx: secctx + * @ctxlen: length of secctx + * + * Change the security context of an inode. Updates the incore security + * context managed by the security module and invokes the fs code as needed + * (via __vfs_setxattr_noperm) to update any backing xattrs that represent the + * context. Example usage: NFS server invokes this hook to change the security + * context in its incore inode and on the backing filesystem to a value + * provided by the client on a SETATTR operation. Must be called with + * inode->i_mutex locked. + * + * Return: Returns 0 on success, error on failure. + */ int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) { return call_int_hook(inode_setsecctx, 0, dentry, ctx, ctxlen); } EXPORT_SYMBOL(security_inode_setsecctx); +/** + * security_inode_getsecctx() - Get the security label of an inode + * @inode: inode + * @ctx: secctx + * @ctxlen: length of secctx + * + * On success, returns 0 and fills out @ctx and @ctxlen with the security + * context for the given @inode. + * + * Return: Returns 0 on success, error on failure. + */ int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) { return call_int_hook(inode_getsecctx, -EOPNOTSUPP, inode, ctx, ctxlen); @@ -3766,6 +3969,16 @@ int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) EXPORT_SYMBOL(security_inode_getsecctx); #ifdef CONFIG_WATCH_QUEUE +/** + * security_post_notification() - Check if a watch notification can be posted + * @w_cred: credentials of the task that set the watch + * @cred: credentials of the task which triggered the watch + * @n: the notification + * + * Check to see if a watch notification can be posted to a particular queue. + * + * Return: Returns 0 if permission is granted. + */ int security_post_notification(const struct cred *w_cred, const struct cred *cred, struct watch_notification *n) @@ -3775,6 +3988,15 @@ int security_post_notification(const struct cred *w_cred, #endif /* CONFIG_WATCH_QUEUE */ #ifdef CONFIG_KEY_NOTIFICATIONS +/** + * security_watch_key() - Check if a task is allowed to watch for key events + * @key: the key to watch + * + * Check to see if a process is allowed to watch for event notifications from + * a key or keyring. + * + * Return: Returns 0 if permission is granted. + */ int security_watch_key(struct key *key) { return call_int_hook(watch_key, 0, key); @@ -4920,6 +5142,15 @@ void security_bpf_prog_free(struct bpf_prog_aux *aux) } #endif /* CONFIG_BPF_SYSCALL */ +/** + * security_locked_down() - Check if a kernel feature is allowed + * @what: requested kernel feature + * + * Determine whether a kernel feature that potentially enables arbitrary code + * execution in kernel space should be permitted. + * + * Return: Returns 0 if permission is granted. + */ int security_locked_down(enum lockdown_reason what) { return call_int_hook(locked_down, 0, what); |