On 15/08/06, Paul Moore wrote:
On Wednesday, August 05, 2015 04:29:37 PM Richard Guy Briggs wrote:
> This adds the ability audit the actions of a not-yet-running process.
>
> This patch implements the ability to filter on the executable path. Instead
> of just hard coding the ino and dev of the executable we care about at the
> moment the rule is inserted into the kernel, use the new audit_fsnotify
> infrastructure to manage this dynamically. This means that if the filename
> does not yet exist but the containing directory does, or if the inode in
> question is unlinked and creat'd (aka updated) the rule will just continue
> to work. If the containing directory is moved or deleted or the filesystem
> is unmounted, the rule is deleted automatically. A future enhancement
> would be to have the rule survive across directory disruptions.
>
> This is a heavily modified version of a patch originally submitted by Eric
> Paris with some ideas from Peter Moody.
>
> Cc: Peter Moody <peter(a)hda3.com>
> Cc: Eric Paris <eparis(a)redhat.com>
> Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
> ---
> include/linux/audit.h | 1 +
> include/uapi/linux/audit.h | 5 +++-
> kernel/audit.h | 4 +++
> kernel/audit_tree.c | 2 +
> kernel/audit_watch.c | 31 +++++++++++++++++++++++++
> kernel/auditfilter.c | 53 ++++++++++++++++++++++++++++++++++++++++-
> kernel/auditsc.c | 3 ++
> 7 files changed, 97 insertions(+), 2 deletions(-)
Merged, although some more minor whitespace tweaks were necessary for
checkpatch. On a related note, if you're not running ./scripts/checlpatch.pl
on your patches before sending them out, I would recommend it. It isn't
perfect, but it can catch some silly things that we all do from time to time.
No excuses... I have been running it pretty regularly and got lazy and
distracted with patch revisions. I can't say I agree with the no space
before closing round parenthesis due to legibility, but will comply.
Also, one last thing. It is pretty late in the -rcX cycle to merge
these two
patches, but considering that we've been talking about these for a while, I'm
reasonably okay merging them. In the future, if it isn't in audit#next by the
time -rc5 is released, it isn't going to make the merge window.
I've been quite aware of that looming merge window... This feature has
been iterating for a while, so there are no big surprises. I was aiming
for earlier. :)
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index c2e7e3a..aee456f 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -59,6 +59,7 @@ struct audit_krule {
> struct audit_field *inode_f; /* quick access to an inode field */
> struct audit_watch *watch; /* associated watch */
> struct audit_tree *tree; /* associated watched tree */
> + struct audit_fsnotify_mark *exe;
> struct list_head rlist; /* entry in audit_{watch,tree}.rules list */
> struct list_head list; /* for AUDIT_LIST* purposes only */
> u64 prio;
> diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> index 971df22..e2ca600 100644
> --- a/include/uapi/linux/audit.h
> +++ b/include/uapi/linux/audit.h
> @@ -266,6 +266,7 @@
> #define AUDIT_OBJ_UID 109
> #define AUDIT_OBJ_GID 110
> #define AUDIT_FIELD_COMPARE 111
> +#define AUDIT_EXE 112
>
> #define AUDIT_ARG0 200
> #define AUDIT_ARG1 (AUDIT_ARG0+1)
> @@ -324,8 +325,10 @@ enum {
>
> #define AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT 0x00000001
> #define AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME 0x00000002
> +#define AUDIT_FEATURE_BITMAP_EXECUTABLE_PATH 0x00000004
> #define AUDIT_FEATURE_BITMAP_ALL (AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT | \
> - AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME)
> + AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME | \
> + AUDIT_FEATURE_BITMAP_EXECUTABLE_PATH )
>
> /* deprecated: AUDIT_VERSION_* */
> #define AUDIT_VERSION_LATEST AUDIT_FEATURE_BITMAP_ALL
> diff --git a/kernel/audit.h b/kernel/audit.h
> index 46d10dd..dadf86a 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -277,6 +277,8 @@ extern char *audit_mark_path(struct audit_fsnotify_mark
> *mark); extern void audit_remove_mark(struct audit_fsnotify_mark
> *audit_mark); extern void audit_remove_mark_rule(struct audit_krule
> *krule);
> extern int audit_mark_compare(struct audit_fsnotify_mark *mark, unsigned
> long ino, dev_t dev); +extern int audit_dupe_exe(struct audit_krule *new,
> struct audit_krule *old); +extern int audit_exe_compare(struct task_struct
> *tsk, struct audit_fsnotify_mark *mark);
>
> #else
> #define audit_put_watch(w) {}
> @@ -292,6 +294,8 @@ extern int audit_mark_compare(struct audit_fsnotify_mark
> *mark, unsigned long in #define audit_remove_mark(m)
> #define audit_remove_mark_rule(k)
> #define audit_mark_compare(m, i, d) 0
> +#define audit_exe_compare(t, m) (-EINVAL)
> +#define audit_dupe_exe(n, o) (-EINVAL)
> #endif /* CONFIG_AUDIT_WATCH */
>
> #ifdef CONFIG_AUDIT_TREE
> diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
> index b0f9877..94ecdab 100644
> --- a/kernel/audit_tree.c
> +++ b/kernel/audit_tree.c
> @@ -479,6 +479,8 @@ static void kill_rules(struct audit_tree *tree)
> if (rule->tree) {
> /* not a half-baked one */
> audit_tree_log_remove_rule(rule);
> + if (entry->rule.exe)
> + audit_remove_mark(entry->rule.exe);
> rule->tree = NULL;
> list_del_rcu(&entry->list);
> list_del(&entry->rule.list);
> diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
> index c668bfc..1255dbf 100644
> --- a/kernel/audit_watch.c
> +++ b/kernel/audit_watch.c
> @@ -312,6 +312,8 @@ static void audit_update_watch(struct audit_parent
> *parent, list_replace(&oentry->rule.list,
> &nentry->rule.list);
> }
> + if (oentry->rule.exe)
> + audit_remove_mark(oentry->rule.exe);
>
> audit_watch_log_rule_change(r, owatch, "updated_rules");
>
> @@ -342,6 +344,8 @@ static void audit_remove_parent_watches(struct
> audit_parent *parent) list_for_each_entry_safe(r, nextr, &w->rules, rlist)
> {
> e = container_of(r, struct audit_entry, rule);
> audit_watch_log_rule_change(r, w, "remove_rule");
> + if (e->rule.exe)
> + audit_remove_mark(e->rule.exe);
> list_del(&r->rlist);
> list_del(&r->list);
> list_del_rcu(&e->list);
> @@ -514,3 +518,30 @@ static int __init audit_watch_init(void)
> return 0;
> }
> device_initcall(audit_watch_init);
> +
> +int audit_dupe_exe(struct audit_krule *new, struct audit_krule *old)
> +{
> + struct audit_fsnotify_mark *audit_mark;
> + char *pathname;
> +
> + pathname = kstrdup(audit_mark_path(old->exe), GFP_KERNEL);
> + if (!pathname)
> + return -ENOMEM;
> +
> + audit_mark = audit_alloc_mark(new, pathname, strlen(pathname));
> + if (IS_ERR(audit_mark)) {
> + kfree(pathname);
> + return PTR_ERR(audit_mark);
> + }
> + new->exe = audit_mark;
> +
> + return 0;
> +}
> +
> +int audit_exe_compare(struct task_struct *tsk, struct audit_fsnotify_mark
> *mark) +{
> + unsigned long ino = tsk->mm->exe_file->f_inode->i_ino;
> + dev_t dev = tsk->mm->exe_file->f_inode->i_sb->s_dev;
> +
> + return audit_mark_compare(mark, ino, dev);
> +}
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index 3d99196..c662638 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -405,6 +405,12 @@ static int audit_field_valid(struct audit_entry *entry,
> struct audit_field *f) if (f->val > AUDIT_MAX_FIELD_COMPARE)
> return -EINVAL;
> break;
> + case AUDIT_EXE:
> + if (f->op != Audit_equal)
> + return -EINVAL;
> + if (entry->rule.listnr != AUDIT_FILTER_EXIT)
> + return -EINVAL;
> + break;
> };
> return 0;
> }
> @@ -419,6 +425,7 @@ static struct audit_entry *audit_data_to_entry(struct
> audit_rule_data *data, size_t remain = datasz - sizeof(struct
> audit_rule_data);
> int i;
> char *str;
> + struct audit_fsnotify_mark *audit_mark;
>
> entry = audit_to_entry_common(data);
> if (IS_ERR(entry))
> @@ -539,6 +546,24 @@ static struct audit_entry *audit_data_to_entry(struct
> audit_rule_data *data, entry->rule.buflen += f->val;
> entry->rule.filterkey = str;
> break;
> + case AUDIT_EXE:
> + if (entry->rule.exe || f->val > PATH_MAX)
> + goto exit_free;
> + str = audit_unpack_string(&bufp, &remain, f->val);
> + if (IS_ERR(str)) {
> + err = PTR_ERR(str);
> + goto exit_free;
> + }
> + entry->rule.buflen += f->val;
> +
> + audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
> + if (IS_ERR(audit_mark)) {
> + kfree(str);
> + err = PTR_ERR(audit_mark);
> + goto exit_free;
> + }
> + entry->rule.exe = audit_mark;
> + break;
> }
> }
>
> @@ -551,6 +576,8 @@ exit_nofree:
> exit_free:
> if (entry->rule.tree)
> audit_put_tree(entry->rule.tree); /* that's the temporary one */
> + if (entry->rule.exe)
> + audit_remove_mark(entry->rule.exe); /* that's the template one */
> audit_free_rule(entry);
> return ERR_PTR(err);
> }
> @@ -615,6 +642,10 @@ static struct audit_rule_data
> *audit_krule_to_data(struct audit_krule *krule) data->buflen +=
> data->values[i] =
> audit_pack_string(&bufp, krule->filterkey);
> break;
> + case AUDIT_EXE:
> + data->buflen += data->values[i] =
> + audit_pack_string(&bufp, audit_mark_path(krule->exe));
> + break;
> case AUDIT_LOGINUID_SET:
> if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
> data->fields[i] = AUDIT_LOGINUID;
> @@ -678,6 +709,12 @@ static int audit_compare_rule(struct audit_krule *a,
> struct audit_krule *b) if (strcmp(a->filterkey, b->filterkey))
> return 1;
> break;
> + case AUDIT_EXE:
> + /* both paths exist based on above type compare */
> + if (strcmp(audit_mark_path(a->exe),
> + audit_mark_path(b->exe)))
> + return 1;
> + break;
> case AUDIT_UID:
> case AUDIT_EUID:
> case AUDIT_SUID:
> @@ -799,8 +836,14 @@ struct audit_entry *audit_dupe_rule(struct audit_krule
> *old) err = -ENOMEM;
> else
> new->filterkey = fk;
> + break;
> + case AUDIT_EXE:
> + err = audit_dupe_exe(new, old);
> + break;
> }
> if (err) {
> + if (new->exe)
> + audit_remove_mark(new->exe);
> audit_free_rule(entry);
> return ERR_PTR(err);
> }
> @@ -963,6 +1006,9 @@ int audit_del_rule(struct audit_entry *entry)
> if (e->rule.tree)
> audit_remove_tree_rule(&e->rule);
>
> + if (e->rule.exe)
> + audit_remove_mark_rule(&e->rule);
> +
> #ifdef CONFIG_AUDITSYSCALL
> if (!dont_count)
> audit_n_rules--;
> @@ -1067,8 +1113,11 @@ int audit_rule_change(int type, __u32 portid, int
> seq, void *data, WARN_ON(1);
> }
>
> - if (err || type == AUDIT_DEL_RULE)
> + if (err || type == AUDIT_DEL_RULE) {
> + if (entry->rule.exe)
> + audit_remove_mark(entry->rule.exe);
> audit_free_rule(entry);
> + }
>
> return err;
> }
> @@ -1360,6 +1409,8 @@ static int update_lsm_rule(struct audit_krule *r)
> return 0;
>
> nentry = audit_dupe_rule(r);
> + if (entry->rule.exe)
> + audit_remove_mark(entry->rule.exe);
> if (IS_ERR(nentry)) {
> /* save the first error encountered for the
> * return value */
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 701ea5c..e9bac2b 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -466,6 +466,9 @@ static int audit_filter_rules(struct task_struct *tsk,
> result = audit_comparator(ctx->ppid, f->op, f->val);
> }
> break;
> + case AUDIT_EXE:
> + result = audit_exe_compare(tsk, rule->exe);
> + break;
> case AUDIT_UID:
> result = audit_uid_comparator(cred->uid, f->op, f->uid);
> break;
--
paul moore
security @ redhat
- RGB
--
Richard Guy Briggs <rbriggs(a)redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545