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-rw-r--r--fs/notify/fanotify/fanotify.c5
-rw-r--r--fs/notify/fanotify/fanotify.h4
-rw-r--r--fs/notify/fanotify/fanotify_user.c86
-rw-r--r--include/linux/fanotify.h5
-rw-r--r--include/uapi/linux/fanotify.h30
5 files changed, 107 insertions, 23 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index a2a15bc4df28..24ec1d66d5a8 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -262,7 +262,7 @@ static int fanotify_get_response(struct fsnotify_group *group,
}
/* userspace responded, convert to something usable */
- switch (event->response & ~FAN_AUDIT) {
+ switch (event->response & FANOTIFY_RESPONSE_ACCESS) {
case FAN_ALLOW:
ret = 0;
break;
@@ -563,6 +563,9 @@ static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path,
pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH_PERM;
pevent->response = 0;
+ pevent->hdr.type = FAN_RESPONSE_INFO_NONE;
+ pevent->hdr.pad = 0;
+ pevent->hdr.len = 0;
pevent->state = FAN_EVENT_INIT;
pevent->path = *path;
path_get(path);
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index f899d610bc08..e8a3c28c5d12 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -428,6 +428,10 @@ struct fanotify_perm_event {
u32 response; /* userspace answer to the event */
unsigned short state; /* state of the event */
int fd; /* fd we passed to userspace for this event */
+ union {
+ struct fanotify_response_info_header hdr;
+ struct fanotify_response_info_audit_rule audit_rule;
+ };
};
static inline struct fanotify_perm_event *
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index caa1211bac8c..8f430bfad487 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -283,19 +283,42 @@ static int create_fd(struct fsnotify_group *group, const struct path *path,
return client_fd;
}
+static int process_access_response_info(const char __user *info,
+ size_t info_len,
+ struct fanotify_response_info_audit_rule *friar)
+{
+ if (info_len != sizeof(*friar))
+ return -EINVAL;
+
+ if (copy_from_user(friar, info, sizeof(*friar)))
+ return -EFAULT;
+
+ if (friar->hdr.type != FAN_RESPONSE_INFO_AUDIT_RULE)
+ return -EINVAL;
+ if (friar->hdr.pad != 0)
+ return -EINVAL;
+ if (friar->hdr.len != sizeof(*friar))
+ return -EINVAL;
+
+ return info_len;
+}
+
/*
* Finish processing of permission event by setting it to ANSWERED state and
* drop group->notification_lock.
*/
static void finish_permission_event(struct fsnotify_group *group,
- struct fanotify_perm_event *event,
- u32 response)
+ struct fanotify_perm_event *event, u32 response,
+ struct fanotify_response_info_audit_rule *friar)
__releases(&group->notification_lock)
{
bool destroy = false;
assert_spin_locked(&group->notification_lock);
- event->response = response;
+ event->response = response & ~FAN_INFO;
+ if (response & FAN_INFO)
+ memcpy(&event->audit_rule, friar, sizeof(*friar));
+
if (event->state == FAN_EVENT_CANCELED)
destroy = true;
else
@@ -306,20 +329,27 @@ static void finish_permission_event(struct fsnotify_group *group,
}
static int process_access_response(struct fsnotify_group *group,
- struct fanotify_response *response_struct)
+ struct fanotify_response *response_struct,
+ const char __user *info,
+ size_t info_len)
{
struct fanotify_perm_event *event;
int fd = response_struct->fd;
u32 response = response_struct->response;
+ int ret = info_len;
+ struct fanotify_response_info_audit_rule friar;
- pr_debug("%s: group=%p fd=%d response=%u\n", __func__, group,
- fd, response);
+ pr_debug("%s: group=%p fd=%d response=%u buf=%p size=%zu\n", __func__,
+ group, fd, response, info, info_len);
/*
* make sure the response is valid, if invalid we do nothing and either
* userspace can send a valid response or we will clean it up after the
* timeout
*/
- switch (response & ~FAN_AUDIT) {
+ if (response & ~FANOTIFY_RESPONSE_VALID_MASK)
+ return -EINVAL;
+
+ switch (response & FANOTIFY_RESPONSE_ACCESS) {
case FAN_ALLOW:
case FAN_DENY:
break;
@@ -327,10 +357,20 @@ static int process_access_response(struct fsnotify_group *group,
return -EINVAL;
}
- if (fd < 0)
+ if ((response & FAN_AUDIT) && !FAN_GROUP_FLAG(group, FAN_ENABLE_AUDIT))
return -EINVAL;
- if ((response & FAN_AUDIT) && !FAN_GROUP_FLAG(group, FAN_ENABLE_AUDIT))
+ if (response & FAN_INFO) {
+ ret = process_access_response_info(info, info_len, &friar);
+ if (ret < 0)
+ return ret;
+ if (fd == FAN_NOFD)
+ return ret;
+ } else {
+ ret = 0;
+ }
+
+ if (fd < 0)
return -EINVAL;
spin_lock(&group->notification_lock);
@@ -340,9 +380,9 @@ static int process_access_response(struct fsnotify_group *group,
continue;
list_del_init(&event->fae.fse.list);
- finish_permission_event(group, event, response);
+ finish_permission_event(group, event, response, &friar);
wake_up(&group->fanotify_data.access_waitq);
- return 0;
+ return ret;
}
spin_unlock(&group->notification_lock);
@@ -804,7 +844,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
if (ret <= 0) {
spin_lock(&group->notification_lock);
finish_permission_event(group,
- FANOTIFY_PERM(event), FAN_DENY);
+ FANOTIFY_PERM(event), FAN_DENY, NULL);
wake_up(&group->fanotify_data.access_waitq);
} else {
spin_lock(&group->notification_lock);
@@ -827,28 +867,32 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
{
- struct fanotify_response response = { .fd = -1, .response = -1 };
+ struct fanotify_response response;
struct fsnotify_group *group;
int ret;
+ const char __user *info_buf = buf + sizeof(struct fanotify_response);
+ size_t info_len;
if (!IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS))
return -EINVAL;
group = file->private_data;
+ pr_debug("%s: group=%p count=%zu\n", __func__, group, count);
+
if (count < sizeof(response))
return -EINVAL;
- count = sizeof(response);
-
- pr_debug("%s: group=%p count=%zu\n", __func__, group, count);
-
- if (copy_from_user(&response, buf, count))
+ if (copy_from_user(&response, buf, sizeof(response)))
return -EFAULT;
- ret = process_access_response(group, &response);
+ info_len = count - sizeof(response);
+
+ ret = process_access_response(group, &response, info_buf, info_len);
if (ret < 0)
count = ret;
+ else
+ count = sizeof(response) + ret;
return count;
}
@@ -876,7 +920,7 @@ static int fanotify_release(struct inode *ignored, struct file *file)
event = list_first_entry(&group->fanotify_data.access_list,
struct fanotify_perm_event, fae.fse.list);
list_del_init(&event->fae.fse.list);
- finish_permission_event(group, event, FAN_ALLOW);
+ finish_permission_event(group, event, FAN_ALLOW, NULL);
spin_lock(&group->notification_lock);
}
@@ -893,7 +937,7 @@ static int fanotify_release(struct inode *ignored, struct file *file)
fsnotify_destroy_event(group, fsn_event);
} else {
finish_permission_event(group, FANOTIFY_PERM(event),
- FAN_ALLOW);
+ FAN_ALLOW, NULL);
}
spin_lock(&group->notification_lock);
}
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index 8ad743def6f3..4f1c4f603118 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -122,6 +122,11 @@
#define ALL_FANOTIFY_EVENT_BITS (FANOTIFY_OUTGOING_EVENTS | \
FANOTIFY_EVENT_FLAGS)
+/* These masks check for invalid bits in permission responses. */
+#define FANOTIFY_RESPONSE_ACCESS (FAN_ALLOW | FAN_DENY)
+#define FANOTIFY_RESPONSE_FLAGS (FAN_AUDIT | FAN_INFO)
+#define FANOTIFY_RESPONSE_VALID_MASK (FANOTIFY_RESPONSE_ACCESS | FANOTIFY_RESPONSE_FLAGS)
+
/* Do not use these old uapi constants internally */
#undef FAN_ALL_CLASS_BITS
#undef FAN_ALL_INIT_FLAGS
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 436258214bb0..cd14c94e9a1e 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -188,15 +188,43 @@ struct fanotify_event_info_error {
__u32 error_count;
};
+/*
+ * User space may need to record additional information about its decision.
+ * The extra information type records what kind of information is included.
+ * The default is none. We also define an extra information buffer whose
+ * size is determined by the extra information type.
+ *
+ * If the information type is Audit Rule, then the information following
+ * is the rule number that triggered the user space decision that
+ * requires auditing.
+ */
+
+#define FAN_RESPONSE_INFO_NONE 0
+#define FAN_RESPONSE_INFO_AUDIT_RULE 1
+
struct fanotify_response {
__s32 fd;
__u32 response;
};
+struct fanotify_response_info_header {
+ __u8 type;
+ __u8 pad;
+ __u16 len;
+};
+
+struct fanotify_response_info_audit_rule {
+ struct fanotify_response_info_header hdr;
+ __u32 rule_number;
+ __u32 subj_trust;
+ __u32 obj_trust;
+};
+
/* Legit userspace responses to a _PERM event */
#define FAN_ALLOW 0x01
#define FAN_DENY 0x02
-#define FAN_AUDIT 0x10 /* Bit mask to create audit record for result */
+#define FAN_AUDIT 0x10 /* Bitmask to create audit record for result */
+#define FAN_INFO 0x20 /* Bitmask to indicate additional information */
/* No fd set in event */
#define FAN_NOFD -1
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-30 19:24:02 +0000