/
procmon.c
1441 lines (1324 loc) · 35.9 KB
/
procmon.c
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/*-
* xnumon - monitor macOS for malicious activity
* https://www.roe.ch/xnumon
*
* Copyright (c) 2017-2019, Daniel Roethlisberger <daniel@roe.ch>.
* All rights reserved.
*
* Licensed under the Open Software License version 3.0.
*/
/*
* Process monitoring core.
*
* Plenty of refactoring opportunities here.
*/
#include "procmon.h"
#include "tommylist.h"
#include "proc.h"
#include "hashes.h"
#include "cachehash.h"
#include "cachecsig.h"
#include "time.h"
#include "work.h"
#include "filemon.h"
#include "atomic.h"
#include <stdbool.h>
#include <stdint.h>
#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <fcntl.h>
#include <signal.h>
#include <errno.h>
#include <time.h>
#include <pthread.h>
static config_t *config;
/* prepq state */
static tommy_list pqlist;
pthread_mutex_t pqmutex; /* protects pqlist */
static uint64_t pqsize; /* current number of elements in pqlist */
static uint64_t pqlookup; /* counts total number of lookups in pq */
static uint64_t pqmiss; /* counts no preloaded image found in pq */
static uint64_t pqdrop; /* counts preloaded imgs removed due max TTL */
static uint64_t pqskip; /* counts non-matching entries skipped in pq */
static atomic32_t images;
static uint64_t liveacq; /* counts live process acquisitions */
static uint64_t miss_bypid; /* counts various miss conditions */
static uint64_t miss_forksubj;
static uint64_t miss_execsubj;
static uint64_t miss_execinterp;
static uint64_t miss_chdirsubj;
static uint64_t miss_getcwd;
static atomic64_t ooms; /* counts events impaired due to OOM */
setstr_t *suppress_image_exec_by_ident;
setstr_t *suppress_image_exec_by_path;
setstr_t *suppress_image_exec_by_ancestor_ident;
setstr_t *suppress_image_exec_by_ancestor_path;
static int image_exec_work(image_exec_t *);
/*
* Ownership of path will be transfered to image_exec; caller must not assume
* that path still exists after calling this function. Path is also freed when
* this function fails and returns NULL.
*
* Thread-safe.
*/
static image_exec_t *
image_exec_new(char *path) {
image_exec_t *image;
assert(path);
image = malloc(sizeof(image_exec_t));
if (!image) {
free(path);
atomic64_inc(&ooms);
return NULL;
}
bzero(image, sizeof(image_exec_t));
pthread_mutex_init(&image->refsmutex, NULL);
image->refs = 1;
#ifdef DEBUG_REFS
fprintf(stderr, "DEBUG_REFS: image_exec_new(%p) refs=%zu\n",
image, image->refs);
#endif
image->path = path;
image->fd = -1;
image->hdr.code = LOGEVT_IMAGE_EXEC;
image->hdr.le_work = (__typeof__(image->hdr.le_work))image_exec_work;
image->hdr.le_free = (__typeof__(image->hdr.le_free))image_exec_free;
atomic32_inc(&images);
return image;
}
/*
* Must not use config because config will be set to NULL before the last
* instances of image_exec are drained out of the log queue.
*/
void
image_exec_free(image_exec_t *image) {
assert(image);
pthread_mutex_lock(&image->refsmutex);
image->refs--;
#ifdef DEBUG_REFS
fprintf(stderr, "DEBUG_REFS: image_exec_free(%p) refs=%zu (was %zu)\n",
image, image->refs, image->refs + 1);
#endif
if (image->refs > 0) {
pthread_mutex_unlock(&image->refsmutex);
return;
}
pthread_mutex_unlock(&image->refsmutex);
pthread_mutex_destroy(&image->refsmutex);
if (image->script)
image_exec_free(image->script);
if (image->prev)
image_exec_free(image->prev);
if (image->argv)
free(image->argv);
if (image->envv)
free(image->envv);
if (image->path)
free(image->path);
if (image->cwd)
free(image->cwd);
if (image->codesign)
codesign_free(image->codesign);
atomic32_dec(&images);
free(image);
}
static void
image_exec_ref(image_exec_t *image) {
assert(image);
pthread_mutex_lock(&image->refsmutex);
image->refs++;
#ifdef DEBUG_REFS
fprintf(stderr, "DEBUG_REFS: image_exec_ref(%p) refs=%zu (was %zu)\n",
image, image->refs, image->refs - 1);
#endif
pthread_mutex_unlock(&image->refsmutex);
}
/*
* Prune history of exec images to config->ancestors previous levels. Go
* back in history and free previous image iff on the whole path, all images
* were exclusively owned by this one, i.e. had a refcount of 1, in order to
* make sure that we are not cutting short another fork's exec history.
*/
static void
image_exec_prune_ancestors(image_exec_t *image, size_t level) {
assert(image);
#ifdef DEBUG_REFS
fprintf(stderr, "DEBUG_REFS: image_exec_prune_ancestors(%p, level %zu) "
"refs=%zu\n", image, level, image->refs);
#endif
if (!image->prev)
return;
if (level >= config->ancestors) {
image_exec_free(image->prev);
image->prev = NULL;
return;
}
if (image->refs == 1)
image_exec_prune_ancestors(image->prev, level + 1);
}
/*
* This function is called multiple times on the same image_exec_t if
* kextlevel > 0.
* Partially thread-safe: only a single thread may call functions on a given
* image_exec_t instance at a time.
* Kern indicates if we are currently handling a kernel module callback.
* Note that attr may be NULL depending on where this function is called from.
*/
static int
image_exec_open(image_exec_t *image, const audit_attr_t *attr, bool kern)
{
char buf[2];
int rv;
int oflag;
if (image->flags & (EIFLAG_STAT|EIFLAG_ATTR)) {
#ifdef DEBUG_EXECIMAGE
fprintf(stderr, "DEBUG_EXECIMAGE: already have stat\n");
#endif
/*
* Switch the file descritor to blocking if we are called on
* an instance that was opened in kext prep queue mode. This
* way we do not have to change all the code to retry all file
* operations when outside of prep queue mode.
*/
if (image->fd != -1 && !kern &&
sys_fd_setblocking(image->fd) == -1)
return -1;
return 0;
}
if (image->flags & EIFLAG_NOPATH) {
if (attr)
goto fallback;
return -1;
}
assert(!!strncmp(image->path, "/dev/", 5));
/*
* Open the image file non-blocking if the kext is waiting for us.
* This is to avoid blocking processes in the kext while a long-running
* low-level disk operation is in progress, such as while Boot Camp
* Assistant is editing partitions or Disk Utility is running fsck.
*/
oflag = O_RDONLY;
if (kern)
oflag |= O_NONBLOCK;
image->fd = open(image->path, oflag);
if (image->fd == -1) {
if (attr)
goto fallback;
return -1;
}
rv = sys_fdattr(&image->stat, image->fd);
if (rv == -1) {
if (attr)
goto fallback;
return -1;
}
if (attr && ((image->stat.mode != attr->mode) ||
(image->stat.uid != attr->uid) ||
(image->stat.gid != attr->gid) ||
(image->stat.dev != attr->dev) ||
(image->stat.ino != attr->ino)))
goto fallback;
/* https://www.in-ulm.de/~mascheck/various/shebang/ */
rv = pread(image->fd, buf, sizeof(buf), 0);
if (rv == -1) {
close(image->fd);
image->fd = -1;
if (attr)
goto fallback;
return -1;
} else if ((rv == 2) && (buf[0] == '#' && buf[1] == '!'))
image->flags |= EIFLAG_SHEBANG;
image->flags |= EIFLAG_STAT;
#ifdef DEBUG_EXECIMAGE
fprintf(stderr, "DEBUG_EXECIMAGE: stat from path=%s\n", image->path);
#endif
return 0;
fallback:
image->stat.mode = attr->mode;
image->stat.uid = attr->uid;
image->stat.gid = attr->gid;
image->stat.dev = attr->dev;
image->stat.ino = attr->ino;
image->flags |= EIFLAG_ATTR;
return 0;
}
/*
* Partially thread-safe: only a single thread may call functions on a given
* image_exec_t instance at a time.
*/
static void
image_exec_close(image_exec_t *image) {
assert(image);
if (image->fd != -1) {
close(image->fd);
image->fd = -1;
}
}
/*
* Kern indicates if we are currently handling a kernel module callback.
*
* Partially thread-safe: only a single thread may call functions on a given
* image_exec_t instance at a time.
*/
static int
image_exec_acquire(image_exec_t *image, bool kern) {
stat_attr_t st;
off_t sz;
bool hit;
int rv;
assert(image);
if (image->flags & EIFLAG_DONE)
return 0;
/* postpone hashes for later offline processing */
if (kern && config->kextlevel < KEXTLEVEL_HASH)
return 0;
/* postpone large binaries for later offline processing */
if (kern && image->stat.size > 1024*1024*8)
return 0;
if (!(image->flags & EIFLAG_HASHES)) {
if (!(image->flags & EIFLAG_STAT) || image->fd == -1) {
image->flags |= EIFLAG_DONE;
return -1;
}
hit = cachehash_get(&image->hashes,
image->stat.dev,
image->stat.ino,
&image->stat.mtime,
&image->stat.ctime,
&image->stat.btime);
if (!hit) {
/* cache miss, calculate hashes */
rv = hashes_fd(&sz, &image->hashes, config->hflags,
image->fd);
if ((rv == -1) || (sz != image->stat.size)) {
close(image->fd);
image->fd = -1;
image->flags |= EIFLAG_DONE;
return -1;
}
/*
* If 2nd stat does not match 1st, invalidate hashes.
*/
rv = sys_fdattr(&st, image->fd);
if (rv == -1) {
close(image->fd);
image->fd = -1;
image->flags |= EIFLAG_DONE;
return -1;
}
/* fd still open, no need to compare dev and ino */
if ((image->stat.size != st.size) ||
(image->stat.mtime.tv_sec != st.mtime.tv_sec) ||
(image->stat.mtime.tv_nsec != st.mtime.tv_nsec) ||
(image->stat.ctime.tv_sec != st.ctime.tv_sec) ||
(image->stat.ctime.tv_nsec != st.ctime.tv_nsec) ||
(image->stat.btime.tv_sec != st.btime.tv_sec) ||
(image->stat.btime.tv_nsec != st.btime.tv_nsec)) {
image->flags &= ~EIFLAG_HASHES;
close(image->fd);
image->fd = -1;
image->flags |= EIFLAG_DONE;
return -1;
}
cachehash_put(image->stat.dev,
image->stat.ino,
&image->stat.mtime,
&image->stat.ctime,
&image->stat.btime,
&image->hashes);
#ifdef DEBUG_EXECIMAGE
fprintf(stderr, "DEBUG_EXECIMAGE: hashes from path=%s\n", image->path);
#endif
}
#ifdef DEBUG_EXECIMAGE
else
fprintf(stderr, "DEBUG_EXECIMAGE: hashes from cache\n");
#endif
image->flags |= EIFLAG_HASHES;
}
#ifdef DEBUG_EXECIMAGE
else
fprintf(stderr, "DEBUG_EXECIMAGE: already have hashes\n");
#endif
/* everything below operates on paths, not open file descriptors */
if (image->fd != -1) {
close(image->fd);
image->fd = -1;
}
/* postpone codesign for later offline processing? */
if (kern && config->kextlevel < KEXTLEVEL_CSIG) {
return 0;
}
/* skip code signing for scripts */
if (image->flags & EIFLAG_SHEBANG) {
image->flags |= EIFLAG_DONE;
return 0;
}
#ifdef DEBUG_EXECIMAGE
if (image->codesign)
fprintf(stderr, "DEBUG_EXECIMAGE: already have codesign\n");
#endif
if (!image->codesign && (image->flags & EIFLAG_HASHES)) {
image->codesign = cachecsig_get(&image->hashes);
if (!image->codesign) {
if (errno == ENOMEM) {
image->flags |= EIFLAG_ENOMEM;
image->flags |= EIFLAG_DONE;
return -1;
}
}
#ifdef DEBUG_EXECIMAGE
else
fprintf(stderr, "DEBUG_EXECIMAGE: codesign from cache\n");
#endif
}
if (!image->codesign && config->codesign) {
/* Postpone codesign verification of processes spawned as part
* of codesign verification during KAuth handling. */
if (kern && (!strcmp(image->path, "/usr/libexec/xpcproxy") ||
!strcmp(image->path, "/usr/sbin/ocspd")))
return 0;
/* Check code signature (can be very slow!) */
image->codesign = codesign_new(image->path, -1);
if (!image->codesign) {
if (errno == ENOMEM)
image->flags |= EIFLAG_ENOMEM;
image->flags |= EIFLAG_DONE;
return -1;
}
/*
* If 3rd stat does not match 1st, invalidate codesign.
* If 3rd stat fails, return error but don't invalidate.
* The codesign routines fail internally if the data is changed
* during signature verification.
*/
rv = sys_pathattr(&st, image->path);
if (rv == -1) {
image->flags |= EIFLAG_DONE;
return -1;
}
if ((image->stat.size != st.size) ||
(image->stat.dev != st.dev) ||
(image->stat.ino != st.ino) ||
(image->stat.mtime.tv_sec != st.mtime.tv_sec) ||
(image->stat.mtime.tv_nsec != st.mtime.tv_nsec) ||
(image->stat.ctime.tv_sec != st.ctime.tv_sec) ||
(image->stat.ctime.tv_nsec != st.ctime.tv_nsec) ||
(image->stat.btime.tv_sec != st.btime.tv_sec) ||
(image->stat.btime.tv_nsec != st.btime.tv_nsec)) {
codesign_free(image->codesign);
image->codesign = NULL;
image->flags |= EIFLAG_DONE;
return -1;
}
cachecsig_put(&image->hashes, image->codesign);
#ifdef DEBUG_EXECIMAGE
fprintf(stderr, "DEBUG_EXECIMAGE: codesign from path=%s\n",
image->path);
#endif
}
image->flags |= EIFLAG_DONE;
return 0;
}
/*
* Return true iff exec image matches either one of the idents in by_ident or
* one of the paths in by_path.
*/
bool
image_exec_match_suppressions(image_exec_t *ie,
setstr_t *by_ident, setstr_t *by_path) {
if (ie->codesign && codesign_is_good(ie->codesign)) {
if (setstr_contains3(by_ident, ie->codesign->ident,
ie->codesign->teamid))
return true;
}
if (ie->path) {
if (setstr_contains(by_path, ie->path))
return true;
}
if (ie->script && ie->script->path) {
if (setstr_contains(by_path, ie->script->path))
return true;
}
return false;
}
/*
* Work function to be executed in the worker thread.
*
* Returning 0 leads to the event being logged, -1 indicates that this event
* should not be logged (may or may not be due to an error).
*
* Partially thread-safe: only a single thread may call functions on a given
* image_exec_t instance at a time.
*/
static int
image_exec_work(image_exec_t *ei) {
#ifdef DEBUG_REFS
fprintf(stderr, "DEBUG_REFS: image_exec_work(%p)\n", ei);
#endif
image_exec_acquire(ei, false);
image_exec_close(ei);
if (ei->script) {
image_exec_acquire(ei->script, false);
image_exec_close(ei->script);
}
if (config->ancestors < SIZE_MAX)
image_exec_prune_ancestors(ei, false);
if (ei->flags & EIFLAG_ENOMEM) {
atomic64_inc(&ooms);
return -1;
}
if (ei->flags & EIFLAG_NOLOG)
return -1;
if (image_exec_match_suppressions(ei, suppress_image_exec_by_ident,
suppress_image_exec_by_path))
return -1;
return 0;
}
/*
* Create new image_exec from pid using runtime lookups.
*/
static image_exec_t *
image_exec_from_pid(pid_t pid) {
image_exec_t *ei;
char *path;
int nopath = 0;
int rv;
path = sys_pidpath(pid);
#ifdef DEBUG_PROCMON
DEBUG(config->debug, "image_exec_from_pid",
"pid=%i path=%s", pid, path);
#endif
if (!path) {
if (errno == ENOMEM) {
atomic64_inc(&ooms);
return NULL;
}
if (asprintf(&path, "<%i>", pid) == -1) {
atomic64_inc(&ooms);
free(path);
return NULL;
}
nopath = 1;
}
ei = image_exec_new(path);
if (!ei)
return NULL;
rv = timespec_nanotime(&ei->hdr.tv);
if (rv == -1) {
image_exec_free(ei);
return NULL;
}
if (nopath)
ei->flags |= EIFLAG_NOPATH;
ei->flags |= EIFLAG_PIDLOOKUP;
ei->pid = pid;
return ei;
}
/*
* Create new proc from pid using runtime lookups. Called after looking up a
* subject in proctab fails and for examination of processes which executed
* before xnumon.
*
* Returns NULL on oom or if the process is not running anymore.
*
* Does oom counting, caller does not need to.
* However, caller needs to count and report miss if this fails.
*/
static proc_t *
procmon_proc_from_pid(pid_t pid, bool log_event, struct timespec *tv) {
proc_t *proc;
pid_t ppid;
proc = proctab_find_or_create(pid);
if (!proc) {
atomic64_inc(&ooms);
return NULL;
}
if (sys_pidbsdinfo(&proc->fork_tv, &ppid, pid) == -1) {
/* process not alive anymore */
proctab_remove(pid, tv);
return NULL;
}
if (proc->cwd) {
free(proc->cwd);
}
proc->cwd = sys_pidcwd(pid);
if (!proc->cwd) {
if (errno == ENOMEM)
atomic64_inc(&ooms);
/* process not alive anymore unless ENOMEM */
proctab_remove(pid, tv);
return NULL;
}
if (proc->image_exec) {
image_exec_free(proc->image_exec);
}
proc->image_exec = image_exec_from_pid(pid);
if (!proc->image_exec) {
/* process not alive anymore unless ENOMEM */
proctab_remove(pid, tv);
return NULL;
}
image_exec_open(proc->image_exec, NULL, false);
/* after acquiring all info from process, go after parent before
* submitting the child into the queues */
if ((ppid >= 0) && (ppid != pid)) {
proc_t *pproc = proctab_find(ppid);
if (!pproc) {
pproc = procmon_proc_from_pid(ppid, log_event, tv);
if (!pproc) {
if (errno == ENOMEM) {
proctab_remove(pid, tv);
return NULL;
}
/* parent not alive anymore */
ppid = -1;
}
}
if (pproc) {
proc->image_exec->prev = pproc->image_exec;
if (proc->image_exec->prev) {
image_exec_ref(proc->image_exec->prev);
}
}
}
if (!log_event || pid == 0)
proc->image_exec->flags |= EIFLAG_NOLOG;
#ifdef DEBUG_REFS
fprintf(stderr, "DEBUG_REFS: work_submit(%p)\n",
proc->image_exec);
#endif
image_exec_ref(proc->image_exec); /* ref is owned by proc */
work_submit(proc->image_exec);
return proc;
}
/*
* Retrieve the current executable image for a given pid.
* Intended to be called from other subsystems when logging process context
* for an event related to a pid.
* Caller must free the returned image_exec_t with image_exec_free().
* On error returns NULL.
* Not thread-safe - must be called from the main thread, not worker or logger!
*
* Caller does error counting and reporting.
*/
image_exec_t *
image_exec_by_pid(pid_t pid, struct timespec *tv) {
proc_t *proc;
proc = proctab_find(pid);
if (!proc) {
proc = procmon_proc_from_pid(pid, true, tv);
if (!proc) {
if (errno != ENOMEM) {
miss_bypid++;
DEBUG(config->debug, "miss_bypid",
"pid=%i", pid);
}
return NULL;
}
liveacq++;
}
image_exec_ref(proc->image_exec);
return proc->image_exec;
}
/*
* Handles fork.
*/
void
procmon_fork(struct timespec *tv,
audit_proc_t *subject, pid_t childpid) {
proc_t *parent, *child;
#ifdef DEBUG_PROCMON
DEBUG(config->debug, "procmon_fork",
"subject->pid=%i childpid=%i\n",
subject->pid, childpid);
#endif
parent = proctab_find(subject->pid);
if (!parent) {
parent = procmon_proc_from_pid(subject->pid, true, tv);
if (!parent) {
if (errno != ENOMEM) {
miss_forksubj++;
DEBUG(config->debug, "miss_forksubj",
"subject.pid=%i childpid=%i",
subject->pid, childpid);
}
return;
}
liveacq++;
}
assert(parent);
proctab_remove(childpid, tv);
child = proctab_create(childpid);
if (!child) {
atomic64_inc(&ooms);
return;
}
child->fork_tv = *tv;
assert(parent->cwd);
child->cwd = strdup(parent->cwd);
if (!child->cwd) {
proctab_remove(childpid, tv);
atomic64_inc(&ooms);
return;
}
assert(parent->image_exec);
child->image_exec = parent->image_exec;
image_exec_ref(child->image_exec);
}
/*
* Only handles true posix_spawn without the POSIX_SPAWN_SETEXEC attribute set.
* POSIX_SPAWN_SETEXEC is treated as regular exec.
*
* Ownership of argv and imagepath is transfered; procmon guarantees that they
* will be freed.
*/
void
procmon_spawn(struct timespec *tv,
audit_proc_t *subject,
pid_t childpid,
char *imagepath, audit_attr_t *attr,
char **argv, char **envv) {
#ifdef DEBUG_PROCMON
DEBUG(config->debug, "procmon_spawn",
"subject->pid=%i childpid=%i imagepath=%s",
subject->pid, childpid, imagepath);
#endif
procmon_fork(tv, subject, childpid);
subject->pid = childpid;
procmon_exec(tv, subject, imagepath, attr, argv, envv);
}
/*
* Append an element to the prepq.
* Called from the kext event handler, if kextlevel is > 0.
*/
static void
prepq_append(image_exec_t *ei) {
pthread_mutex_lock(&pqmutex);
tommy_list_insert_tail(&pqlist, &ei->hdr.node, ei);
pqsize++;
pthread_mutex_unlock(&pqmutex);
}
/*
* Remove an existing (!) element from the prepq.
* Called from the exec handler only (!).
*
* The chosen locking strategy only works if only a single thread is removing
* elements and one or more other threads are only adding elements.
*/
static void
prepq_remove_existing(image_exec_t *ei) {
pthread_mutex_lock(&pqmutex);
tommy_list_remove_existing(&pqlist,
&ei->hdr.node);
pqsize--;
pthread_mutex_unlock(&pqmutex);
}
/*
* Look up the corresponding exec images acquired by kext events before the
* audit event was committed. Linking the audit event to the correct kext
* events even when events are being lost for some reason is probably the most
* tricky part of all of this.
*/
static void
prepq_lookup(image_exec_t **image, image_exec_t **interp,
proc_t *proc, char *imagepath, audit_attr_t *attr, char **argv) {
*image = NULL;
*interp = NULL;
pqlookup++;
for (tommy_node *node = tommy_list_head(&pqlist);
node; node = node->next) {
image_exec_t *ei = node->data;
assert(ei);
if (!*image) {
/*
* Find the image based on (pid,dev,ino) or
* (pid,basename(path)) as a fallback if no attr is
* available from the audit event. When the kernel
* passes a wrong path to the audit framework, it does
* not provide attributes; in that case we have to rely
* on just the pid and the basename.
*/
if (ei->pid == proc->pid &&
((attr && ei->stat.dev == attr->dev &&
ei->stat.ino == attr->ino) ||
(!attr &&
!sys_basenamecmp(ei->path, imagepath)))) {
/* we have a match */
prepq_remove_existing(ei);
*image = ei;
/* script executions always have the
* interpreter as argv[0] and the script file
* as argv[1]. The remaining arguments are the
* arguments passed to the scripts, if any */
if (((*image)->flags & EIFLAG_SHEBANG) &&
argv && argv[0] && argv[1])
continue;
break;
}
} else {
assert(!*interp);
assert(argv && argv[0] && argv[1]);
/* #! can be relative path and we have no attr now.
* Using (pid,basename(path)) is the best we can do
* at this point. */
if (ei->pid == proc->pid &&
!sys_basenamecmp(ei->path, argv[0])) {
/* we have a match */
prepq_remove_existing(ei);
*interp = ei;
break;
}
}
pqskip++;
#if 0
DEBUG(config->debug, "prepq_skip",
"looking for %s[%i]: skipped %s[%i]",
imagepath, proc->pid, ei->path, ei->pid);
#endif
if (++ei->pqttl == MAXPQTTL) {
DEBUG(config->debug, "prepq_drop",
"looking for %s[%i]: dropped %s[%i]",
imagepath, proc->pid, ei->path, ei->pid);
prepq_remove_existing(ei);
image_exec_free(ei);
pqdrop++;
}
}
assert(!(*interp && !*image));
}
/*
* For scripts, this will be called once, with argv[0] as the interpreter and
* argv[1+] as argv[0+] of the script execution, imagepath as the script and
* attr as the file attributes of the script.
*
* Ownership of argv and imagepath is transfered, procmon guarantees that they
* will be freed. Only argv and attr can be NULL.
*/
void
procmon_exec(struct timespec *tv,
audit_proc_t *subject,
char *imagepath, audit_attr_t *attr,
char **argv, char **envv) {
proc_t *proc;
image_exec_t *prev_image_exec;
char *cwd;
#ifdef DEBUG_PROCMON
DEBUG(config->debug, "procmon_exec",
"subject->pid=%i imagepath=%s", subject->pid, imagepath);
#endif
proc = proctab_find(subject->pid);
if (!proc) {
proc = procmon_proc_from_pid(subject->pid, true, tv);
if (!proc) {
if (errno != ENOMEM) {
miss_execsubj++;
DEBUG(config->debug, "miss_execsubj",
"subject.pid=%i imagepath=%s argv[0]=%s",
subject->pid, imagepath,
argv ? argv[0] : NULL);
}
free(imagepath);
if (argv)
free(argv);
if (envv)
free(envv);
return;
}
liveacq++;
}
assert(proc);
image_exec_t *image, *interp;
prepq_lookup(&image, &interp, proc, imagepath, attr, argv);
#if 0
if (image)
fprintf(stderr, "found kext image "
"pid=%i path=%s is_script=%i\n",
image->pid, image->path,
image->flags & EIFLAG_SHEBANG);
if (interp)
fprintf(stderr, "found kext interp "
"pid=%i path=%s is_script=%i\n",
interp->pid, interp->path,
interp->flags & EIFLAG_SHEBANG);
#endif
if (!image) {
DEBUG(config->debug && config->kextlevel > 0,
"prepq_miss",
"looking for %s[%i]: not found (image)",
imagepath, proc->pid);
pqmiss++;
image = image_exec_new(imagepath);
if (!image) {
/* no counter, oom is the only reason this can happen */
if (argv)
free(argv);
if (envv)
free(envv);
assert(!interp);
return;
}
} else {
free(imagepath);
}
assert(image);
image_exec_open(image, attr, false);
/*
* XXX why are we not using the shebang from the script file here if
* argv is unavailable?
*/
if (image->flags & EIFLAG_SHEBANG) {
if (!interp) {
DEBUG(config->debug && config->kextlevel > 0,
"prepq_miss",
"looking for %s[%i]: not found (interp "
"argv[0]=%s)",
imagepath, proc->pid, argv ? argv[0] : NULL);
pqmiss++;
if (!argv) {
miss_execinterp++;
DEBUG(config->debug, "miss_execinterp",
"subject.pid=%i imagepath=%s "
"argv=NULL attr:%s",
subject->pid, imagepath,
attr ? "y" : "n");
image_exec_free(image);
if (envv)
free(envv);
return;
}
if (argv[0][0] == '/' || proc->cwd) {
char *p = sys_realpath(argv[0], proc->cwd);
if (!p) {
if (errno == ENOMEM)
atomic64_inc(&ooms);
miss_execinterp++;
DEBUG(config->debug,
"miss_execinterp",
"subject.pid=%i imagepath=%s "
"argv[0]=%s argv[1]=%s "
"attr:%s",
subject->pid, imagepath,
argv[0], argv[1],
attr ? "y" : "n");
image_exec_free(image);
free(argv);
if (envv)
free(envv);
return;
}
interp = image_exec_new(p);
}
if (!interp) {
miss_execinterp++;
DEBUG(config->debug, "miss_execinterp",
"subject.pid=%i imagepath=%s "
"argv[0]=%s argv[1]=%s attr:%s",
subject->pid, imagepath,
argv[0], argv[1],
attr ? "y" : "n");
image_exec_free(image);
free(argv);
if (envv)