audit: fix event coverage of AUDIT_ANOM_LINK
The userspace audit tools didn't like the existing formatting of the
AUDIT_ANOM_LINK event. It needed to be expanded to emit an AUDIT_PATH
event as well, so this implements the change. The bulk of the patch is
moving code out of auditsc.c into audit.c and audit.h for general use.
It expands audit_log_name to include an optional "struct path" argument
for the simple case of just needing to report a pathname. This also
makes
audit_log_task_info available when syscall auditing is not enabled,
since
it is needed in either case for process details.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Steve Grubb <sgrubb@redhat.com>
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 17e9a26..add3086 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -76,11 +76,6 @@
#define AUDITSC_SUCCESS 1
#define AUDITSC_FAILURE 2
-/* AUDIT_NAMES is the number of slots we reserve in the audit_context
- * for saving names from getname(). If we get more names we will allocate
- * a name dynamically and also add those to the list anchored by names_list. */
-#define AUDIT_NAMES 5
-
/* no execve audit message should be longer than this (userspace limits) */
#define MAX_EXECVE_AUDIT_LEN 7500
@@ -90,44 +85,6 @@
/* determines whether we collect data for signals sent */
int audit_signals;
-struct audit_cap_data {
- kernel_cap_t permitted;
- kernel_cap_t inheritable;
- union {
- unsigned int fE; /* effective bit of a file capability */
- kernel_cap_t effective; /* effective set of a process */
- };
-};
-
-/* When fs/namei.c:getname() is called, we store the pointer in name and
- * we don't let putname() free it (instead we free all of the saved
- * pointers at syscall exit time).
- *
- * Further, in fs/namei.c:path_lookup() we store the inode and device.
- */
-struct audit_names {
- struct list_head list; /* audit_context->names_list */
- struct filename *name;
- unsigned long ino;
- dev_t dev;
- umode_t mode;
- kuid_t uid;
- kgid_t gid;
- dev_t rdev;
- u32 osid;
- struct audit_cap_data fcap;
- unsigned int fcap_ver;
- int name_len; /* number of name's characters to log */
- unsigned char type; /* record type */
- bool name_put; /* call __putname() for this name */
- /*
- * This was an allocated audit_names and not from the array of
- * names allocated in the task audit context. Thus this name
- * should be freed on syscall exit
- */
- bool should_free;
-};
-
struct audit_aux_data {
struct audit_aux_data *next;
int type;
@@ -175,106 +132,6 @@
struct audit_chunk *c[31];
};
-/* The per-task audit context. */
-struct audit_context {
- int dummy; /* must be the first element */
- int in_syscall; /* 1 if task is in a syscall */
- enum audit_state state, current_state;
- unsigned int serial; /* serial number for record */
- int major; /* syscall number */
- struct timespec ctime; /* time of syscall entry */
- unsigned long argv[4]; /* syscall arguments */
- long return_code;/* syscall return code */
- u64 prio;
- int return_valid; /* return code is valid */
- /*
- * The names_list is the list of all audit_names collected during this
- * syscall. The first AUDIT_NAMES entries in the names_list will
- * actually be from the preallocated_names array for performance
- * reasons. Except during allocation they should never be referenced
- * through the preallocated_names array and should only be found/used
- * by running the names_list.
- */
- struct audit_names preallocated_names[AUDIT_NAMES];
- int name_count; /* total records in names_list */
- struct list_head names_list; /* anchor for struct audit_names->list */
- char * filterkey; /* key for rule that triggered record */
- struct path pwd;
- struct audit_aux_data *aux;
- struct audit_aux_data *aux_pids;
- struct sockaddr_storage *sockaddr;
- size_t sockaddr_len;
- /* Save things to print about task_struct */
- pid_t pid, ppid;
- kuid_t uid, euid, suid, fsuid;
- kgid_t gid, egid, sgid, fsgid;
- unsigned long personality;
- int arch;
-
- pid_t target_pid;
- kuid_t target_auid;
- kuid_t target_uid;
- unsigned int target_sessionid;
- u32 target_sid;
- char target_comm[TASK_COMM_LEN];
-
- struct audit_tree_refs *trees, *first_trees;
- struct list_head killed_trees;
- int tree_count;
-
- int type;
- union {
- struct {
- int nargs;
- long args[AUDITSC_ARGS];
- } socketcall;
- struct {
- kuid_t uid;
- kgid_t gid;
- umode_t mode;
- u32 osid;
- int has_perm;
- uid_t perm_uid;
- gid_t perm_gid;
- umode_t perm_mode;
- unsigned long qbytes;
- } ipc;
- struct {
- mqd_t mqdes;
- struct mq_attr mqstat;
- } mq_getsetattr;
- struct {
- mqd_t mqdes;
- int sigev_signo;
- } mq_notify;
- struct {
- mqd_t mqdes;
- size_t msg_len;
- unsigned int msg_prio;
- struct timespec abs_timeout;
- } mq_sendrecv;
- struct {
- int oflag;
- umode_t mode;
- struct mq_attr attr;
- } mq_open;
- struct {
- pid_t pid;
- struct audit_cap_data cap;
- } capset;
- struct {
- int fd;
- int flags;
- } mmap;
- };
- int fds[2];
-
-#if AUDIT_DEBUG
- int put_count;
- int ino_count;
-#endif
-};
-
static inline int open_arg(int flags, int mask)
{
int n = ACC_MODE(flags);
@@ -1109,88 +966,6 @@
kfree(context);
}
-int audit_log_task_context(struct audit_buffer *ab)
-{
- char *ctx = NULL;
- unsigned len;
- int error;
- u32 sid;
-
- security_task_getsecid(current, &sid);
- if (!sid)
- return 0;
-
- error = security_secid_to_secctx(sid, &ctx, &len);
- if (error) {
- if (error != -EINVAL)
- goto error_path;
- return 0;
- }
-
- audit_log_format(ab, " subj=%s", ctx);
- security_release_secctx(ctx, len);
- return 0;
-
-error_path:
- audit_panic("error in audit_log_task_context");
- return error;
-}
-
-EXPORT_SYMBOL(audit_log_task_context);
-
-void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
-{
- const struct cred *cred;
- char name[sizeof(tsk->comm)];
- struct mm_struct *mm = tsk->mm;
- char *tty;
-
- if (!ab)
- return;
-
- /* tsk == current */
- cred = current_cred();
-
- spin_lock_irq(&tsk->sighand->siglock);
- if (tsk->signal && tsk->signal->tty)
- tty = tsk->signal->tty->name;
- else
- tty = "(none)";
- spin_unlock_irq(&tsk->sighand->siglock);
-
-
- audit_log_format(ab,
- " ppid=%ld pid=%d auid=%u uid=%u gid=%u"
- " euid=%u suid=%u fsuid=%u"
- " egid=%u sgid=%u fsgid=%u ses=%u tty=%s",
- sys_getppid(),
- tsk->pid,
- from_kuid(&init_user_ns, tsk->loginuid),
- from_kuid(&init_user_ns, cred->uid),
- from_kgid(&init_user_ns, cred->gid),
- from_kuid(&init_user_ns, cred->euid),
- from_kuid(&init_user_ns, cred->suid),
- from_kuid(&init_user_ns, cred->fsuid),
- from_kgid(&init_user_ns, cred->egid),
- from_kgid(&init_user_ns, cred->sgid),
- from_kgid(&init_user_ns, cred->fsgid),
- tsk->sessionid, tty);
-
- get_task_comm(name, tsk);
- audit_log_format(ab, " comm=");
- audit_log_untrustedstring(ab, name);
-
- if (mm) {
- down_read(&mm->mmap_sem);
- if (mm->exe_file)
- audit_log_d_path(ab, " exe=", &mm->exe_file->f_path);
- up_read(&mm->mmap_sem);
- }
- audit_log_task_context(ab);
-}
-
-EXPORT_SYMBOL(audit_log_task_info);
-
static int audit_log_pid_context(struct audit_context *context, pid_t pid,
kuid_t auid, kuid_t uid, unsigned int sessionid,
u32 sid, char *comm)
@@ -1408,35 +1183,6 @@
kfree(buf);
}
-static void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
-{
- int i;
-
- audit_log_format(ab, " %s=", prefix);
- CAP_FOR_EACH_U32(i) {
- audit_log_format(ab, "%08x", cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
- }
-}
-
-static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
-{
- kernel_cap_t *perm = &name->fcap.permitted;
- kernel_cap_t *inh = &name->fcap.inheritable;
- int log = 0;
-
- if (!cap_isclear(*perm)) {
- audit_log_cap(ab, "cap_fp", perm);
- log = 1;
- }
- if (!cap_isclear(*inh)) {
- audit_log_cap(ab, "cap_fi", inh);
- log = 1;
- }
-
- if (log)
- audit_log_format(ab, " cap_fe=%d cap_fver=%x", name->fcap.fE, name->fcap_ver);
-}
-
static void show_special(struct audit_context *context, int *call_panic)
{
struct audit_buffer *ab;
@@ -1534,68 +1280,6 @@
audit_log_end(ab);
}
-static void audit_log_name(struct audit_context *context, struct audit_names *n,
- int record_num, int *call_panic)
-{
- struct audit_buffer *ab;
- ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
- if (!ab)
- return; /* audit_panic has been called */
-
- audit_log_format(ab, "item=%d", record_num);
-
- if (n->name) {
- switch (n->name_len) {
- case AUDIT_NAME_FULL:
- /* log the full path */
- audit_log_format(ab, " name=");
- audit_log_untrustedstring(ab, n->name->name);
- break;
- case 0:
- /* name was specified as a relative path and the
- * directory component is the cwd */
- audit_log_d_path(ab, " name=", &context->pwd);
- break;
- default:
- /* log the name's directory component */
- audit_log_format(ab, " name=");
- audit_log_n_untrustedstring(ab, n->name->name,
- n->name_len);
- }
- } else
- audit_log_format(ab, " name=(null)");
-
- if (n->ino != (unsigned long)-1) {
- audit_log_format(ab, " inode=%lu"
- " dev=%02x:%02x mode=%#ho"
- " ouid=%u ogid=%u rdev=%02x:%02x",
- n->ino,
- MAJOR(n->dev),
- MINOR(n->dev),
- n->mode,
- from_kuid(&init_user_ns, n->uid),
- from_kgid(&init_user_ns, n->gid),
- MAJOR(n->rdev),
- MINOR(n->rdev));
- }
- if (n->osid != 0) {
- char *ctx = NULL;
- u32 len;
- if (security_secid_to_secctx(
- n->osid, &ctx, &len)) {
- audit_log_format(ab, " osid=%u", n->osid);
- *call_panic = 2;
- } else {
- audit_log_format(ab, " obj=%s", ctx);
- security_release_secctx(ctx, len);
- }
- }
-
- audit_log_fcaps(ab, n);
-
- audit_log_end(ab);
-}
-
static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
{
int i, call_panic = 0;
@@ -1713,7 +1397,7 @@
i = 0;
list_for_each_entry(n, &context->names_list, list)
- audit_log_name(context, n, i++, &call_panic);
+ audit_log_name(context, n, NULL, i++, &call_panic);
/* Send end of event record to help user space know we are finished */
ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
@@ -2078,41 +1762,6 @@
#endif
}
-static inline int audit_copy_fcaps(struct audit_names *name, const struct dentry *dentry)
-{
- struct cpu_vfs_cap_data caps;
- int rc;
-
- if (!dentry)
- return 0;
-
- rc = get_vfs_caps_from_disk(dentry, &caps);
- if (rc)
- return rc;
-
- name->fcap.permitted = caps.permitted;
- name->fcap.inheritable = caps.inheritable;
- name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
- name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
-
- return 0;
-}
-
-
-/* Copy inode data into an audit_names. */
-static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
- const struct inode *inode)
-{
- name->ino = inode->i_ino;
- name->dev = inode->i_sb->s_dev;
- name->mode = inode->i_mode;
- name->uid = inode->i_uid;
- name->gid = inode->i_gid;
- name->rdev = inode->i_rdev;
- security_inode_getsecid(inode, &name->osid);
- audit_copy_fcaps(name, dentry);
-}
-
/**
* __audit_inode - store the inode and device from a lookup
* @name: name being audited