diff options
Diffstat (limited to 'security/security.c')
| -rw-r--r-- | security/security.c | 117 |
1 files changed, 104 insertions, 13 deletions
diff --git a/security/security.c b/security/security.c index 344bf1327d7e..51de970fbb1e 100644 --- a/security/security.c +++ b/security/security.c @@ -34,6 +34,39 @@ /* How many LSMs were built into the kernel? */ #define LSM_COUNT (__end_lsm_info - __start_lsm_info) +/* + * These are descriptions of the reasons that can be passed to the + * security_locked_down() LSM hook. Placing this array here allows + * all security modules to use the same descriptions for auditing + * purposes. + */ +const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = { + [LOCKDOWN_NONE] = "none", + [LOCKDOWN_MODULE_SIGNATURE] = "unsigned module loading", + [LOCKDOWN_DEV_MEM] = "/dev/mem,kmem,port", + [LOCKDOWN_EFI_TEST] = "/dev/efi_test access", + [LOCKDOWN_KEXEC] = "kexec of unsigned images", + [LOCKDOWN_HIBERNATION] = "hibernation", + [LOCKDOWN_PCI_ACCESS] = "direct PCI access", + [LOCKDOWN_IOPORT] = "raw io port access", + [LOCKDOWN_MSR] = "raw MSR access", + [LOCKDOWN_ACPI_TABLES] = "modifying ACPI tables", + [LOCKDOWN_PCMCIA_CIS] = "direct PCMCIA CIS storage", + [LOCKDOWN_TIOCSSERIAL] = "reconfiguration of serial port IO", + [LOCKDOWN_MODULE_PARAMETERS] = "unsafe module parameters", + [LOCKDOWN_MMIOTRACE] = "unsafe mmio", + [LOCKDOWN_DEBUGFS] = "debugfs access", + [LOCKDOWN_XMON_WR] = "xmon write access", + [LOCKDOWN_INTEGRITY_MAX] = "integrity", + [LOCKDOWN_KCORE] = "/proc/kcore access", + [LOCKDOWN_KPROBES] = "use of kprobes", + [LOCKDOWN_BPF_READ] = "use of bpf to read kernel RAM", + [LOCKDOWN_PERF] = "unsafe use of perf", + [LOCKDOWN_TRACEFS] = "use of tracefs", + [LOCKDOWN_XMON_RW] = "xmon read and write access", + [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality", +}; + struct security_hook_heads security_hook_heads __lsm_ro_after_init; static BLOCKING_NOTIFIER_HEAD(blocking_lsm_notifier_chain); @@ -636,6 +669,25 @@ static void __init lsm_early_task(struct task_struct *task) } /* + * The default value of the LSM hook is defined in linux/lsm_hook_defs.h and + * can be accessed with: + * + * LSM_RET_DEFAULT(<hook_name>) + * + * The macros below define static constants for the default value of each + * LSM hook. + */ +#define LSM_RET_DEFAULT(NAME) (NAME##_default) +#define DECLARE_LSM_RET_DEFAULT_void(DEFAULT, NAME) +#define DECLARE_LSM_RET_DEFAULT_int(DEFAULT, NAME) \ + static const int LSM_RET_DEFAULT(NAME) = (DEFAULT); +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ + DECLARE_LSM_RET_DEFAULT_##RET(DEFAULT, NAME) + +#include <linux/lsm_hook_defs.h> +#undef LSM_HOOK + +/* * Hook list operation macros. * * call_void_hook: @@ -1305,16 +1357,16 @@ int security_inode_getsecurity(struct inode *inode, const char *name, void **buf int rc; if (unlikely(IS_PRIVATE(inode))) - return -EOPNOTSUPP; + return LSM_RET_DEFAULT(inode_getsecurity); /* * Only one module will provide an attribute with a given name. */ hlist_for_each_entry(hp, &security_hook_heads.inode_getsecurity, list) { rc = hp->hook.inode_getsecurity(inode, name, buffer, alloc); - if (rc != -EOPNOTSUPP) + if (rc != LSM_RET_DEFAULT(inode_getsecurity)) return rc; } - return -EOPNOTSUPP; + return LSM_RET_DEFAULT(inode_getsecurity); } int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) @@ -1323,17 +1375,17 @@ int security_inode_setsecurity(struct inode *inode, const char *name, const void int rc; if (unlikely(IS_PRIVATE(inode))) - return -EOPNOTSUPP; + return LSM_RET_DEFAULT(inode_setsecurity); /* * Only one module will provide an attribute with a given name. */ hlist_for_each_entry(hp, &security_hook_heads.inode_setsecurity, list) { rc = hp->hook.inode_setsecurity(inode, name, value, size, flags); - if (rc != -EOPNOTSUPP) + if (rc != LSM_RET_DEFAULT(inode_setsecurity)) return rc; } - return -EOPNOTSUPP; + return LSM_RET_DEFAULT(inode_setsecurity); } int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) @@ -1707,12 +1759,12 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { int thisrc; - int rc = -ENOSYS; + int rc = LSM_RET_DEFAULT(task_prctl); struct security_hook_list *hp; hlist_for_each_entry(hp, &security_hook_heads.task_prctl, list) { thisrc = hp->hook.task_prctl(option, arg2, arg3, arg4, arg5); - if (thisrc != -ENOSYS) { + if (thisrc != LSM_RET_DEFAULT(task_prctl)) { rc = thisrc; if (thisrc != 0) break; @@ -1884,7 +1936,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, continue; return hp->hook.getprocattr(p, name, value); } - return -EINVAL; + return LSM_RET_DEFAULT(getprocattr); } int security_setprocattr(const char *lsm, const char *name, void *value, @@ -1897,7 +1949,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value, continue; return hp->hook.setprocattr(name, value, size); } - return -EINVAL; + return LSM_RET_DEFAULT(setprocattr); } int security_netlink_send(struct sock *sk, struct sk_buff *skb) @@ -1913,8 +1965,20 @@ EXPORT_SYMBOL(security_ismaclabel); int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) { - return call_int_hook(secid_to_secctx, -EOPNOTSUPP, secid, secdata, - seclen); + struct security_hook_list *hp; + int rc; + + /* + * Currently, only one LSM can implement secid_to_secctx (i.e this + * LSM hook is not "stackable"). + */ + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { + rc = hp->hook.secid_to_secctx(secid, secdata, seclen); + if (rc != LSM_RET_DEFAULT(secid_to_secctx)) + return rc; + } + + return LSM_RET_DEFAULT(secid_to_secctx); } EXPORT_SYMBOL(security_secid_to_secctx); @@ -2282,7 +2346,7 @@ int security_xfrm_state_pol_flow_match(struct xfrm_state *x, const struct flowi *fl) { struct security_hook_list *hp; - int rc = 1; + int rc = LSM_RET_DEFAULT(xfrm_state_pol_flow_match); /* * Since this function is expected to return 0 or 1, the judgment @@ -2403,3 +2467,30 @@ int security_locked_down(enum lockdown_reason what) return call_int_hook(locked_down, 0, what); } EXPORT_SYMBOL(security_locked_down); + +#ifdef CONFIG_PERF_EVENTS +int security_perf_event_open(struct perf_event_attr *attr, int type) +{ + return call_int_hook(perf_event_open, 0, attr, type); +} + +int security_perf_event_alloc(struct perf_event *event) +{ + return call_int_hook(perf_event_alloc, 0, event); +} + +void security_perf_event_free(struct perf_event *event) +{ + call_void_hook(perf_event_free, event); +} + +int security_perf_event_read(struct perf_event *event) +{ + return call_int_hook(perf_event_read, 0, event); +} + +int security_perf_event_write(struct perf_event *event) +{ + return call_int_hook(perf_event_write, 0, event); +} +#endif /* CONFIG_PERF_EVENTS */ |