1 // SPDX-License-Identifier: GPL-2.0
11 #include <linux/sched/signal.h>
23 	return p1->mnt == p2->mnt && p1->dentry == p2->dentry;  in fanotify_path_equal()
28 	return hash_ptr(path->dentry, FANOTIFY_EVENT_HASH_BITS) ^  in fanotify_hash_path()
29 		hash_ptr(path->mnt, FANOTIFY_EVENT_HASH_BITS);  in fanotify_hash_path()
35 	return fsid1->val[0] == fsid2->val[0] && fsid1->val[1] == fsid2->val[1];  in fanotify_fsid_equal()
40 	return hash_32(fsid->val[0], FANOTIFY_EVENT_HASH_BITS) ^  in fanotify_hash_fsid()
41 		hash_32(fsid->val[1], FANOTIFY_EVENT_HASH_BITS);  in fanotify_hash_fsid()
47 	if (fh1->type != fh2->type || fh1->len != fh2->len)  in fanotify_fh_equal()
50 	return !fh1->len ||  in fanotify_fh_equal()
51 		!memcmp(fanotify_fh_buf(fh1), fanotify_fh_buf(fh2), fh1->len);  in fanotify_fh_equal()
56 	long salt = (long)fh->type | (long)fh->len << 8;  in fanotify_hash_fh()
61 	return full_name_hash((void *)salt, fanotify_fh_buf(fh), fh->len);  in fanotify_hash_fh()
68 	if (!ffe1->object_fh.len)  in fanotify_fid_event_equal()
71 	return fanotify_fsid_equal(&ffe1->fsid, &ffe2->fsid) &&  in fanotify_fid_event_equal()
72 		fanotify_fh_equal(&ffe1->object_fh, &ffe2->object_fh);  in fanotify_fid_event_equal()
78 	if (info1->dir_fh_totlen != info2->dir_fh_totlen ||  in fanotify_info_equal()
79 	    info1->dir2_fh_totlen != info2->dir2_fh_totlen ||  in fanotify_info_equal()
80 	    info1->file_fh_totlen != info2->file_fh_totlen ||  in fanotify_info_equal()
81 	    info1->name_len != info2->name_len ||  in fanotify_info_equal()
82 	    info1->name2_len != info2->name2_len)  in fanotify_info_equal()
85 	if (info1->dir_fh_totlen &&  in fanotify_info_equal()
90 	if (info1->dir2_fh_totlen &&  in fanotify_info_equal()
95 	if (info1->file_fh_totlen &&  in fanotify_info_equal()
100 	if (info1->name_len &&  in fanotify_info_equal()
102 		   info1->name_len))  in fanotify_info_equal()
105 	return !info1->name2_len ||  in fanotify_info_equal()
107 			info1->name2_len);  in fanotify_info_equal()
113 	struct fanotify_info *info1 = &fne1->info;  in fanotify_name_event_equal()
114 	struct fanotify_info *info2 = &fne2->info;  in fanotify_name_event_equal()
117 	if (!info1->dir_fh_totlen)  in fanotify_name_event_equal()
120 	if (!fanotify_fsid_equal(&fne1->fsid, &fne2->fsid))  in fanotify_name_event_equal()
130 	if (!fanotify_fsid_equal(&fee1->fsid, &fee2->fsid))  in fanotify_error_event_equal()
141 	if (old->hash != new->hash ||  in fanotify_should_merge()
142 	    old->type != new->type || old->pid != new->pid)  in fanotify_should_merge()
153 	if ((old->mask & FS_ISDIR) != (new->mask & FS_ISDIR))  in fanotify_should_merge()
160 	if ((old->mask & FAN_RENAME) != (new->mask & FAN_RENAME))  in fanotify_should_merge()
163 	switch (old->type) {  in fanotify_should_merge()
187 static int fanotify_merge(struct fsnotify_group *group,  in fanotify_merge()  argument
191 	unsigned int bucket = fanotify_event_hash_bucket(group, new);  in fanotify_merge()
192 	struct hlist_head *hlist = &group->fanotify_data.merge_hash[bucket];  in fanotify_merge()
195 	pr_debug("%s: group=%p event=%p bucket=%u\n", __func__,  in fanotify_merge()
196 		 group, event, bucket);  in fanotify_merge()
203 	if (fanotify_is_perm_event(new->mask))  in fanotify_merge()
210 			old->mask |= new->mask;  in fanotify_merge()
212 			if (fanotify_is_error_event(old->mask))  in fanotify_merge()
213 				FANOTIFY_EE(old)->err_count++;  in fanotify_merge()
225  * by a signal). The function returns 0 in case access got allowed by userspace,
226  * -EPERM in case userspace disallowed the access, and -ERESTARTSYS in case
227  * the wait got interrupted by a signal.
229 static int fanotify_get_response(struct fsnotify_group *group,  in fanotify_get_response()  argument
235 	pr_debug("%s: group=%p event=%p\n", __func__, group, event);  in fanotify_get_response()
237 	ret = wait_event_killable(group->fanotify_data.access_waitq,  in fanotify_get_response()
238 				  event->state == FAN_EVENT_ANSWERED);  in fanotify_get_response()
239 	/* Signal pending? */  in fanotify_get_response()
241 		spin_lock(&group->notification_lock);  in fanotify_get_response()
243 		if (event->state == FAN_EVENT_REPORTED) {  in fanotify_get_response()
245 			event->state = FAN_EVENT_CANCELED;  in fanotify_get_response()
246 			spin_unlock(&group->notification_lock);  in fanotify_get_response()
250 		if (event->state == FAN_EVENT_INIT) {  in fanotify_get_response()
251 			fsnotify_remove_queued_event(group, &event->fae.fse);  in fanotify_get_response()
253 			WARN_ON_ONCE(!hlist_unhashed(&event->fae.merge_list));  in fanotify_get_response()
256 		 * Event may be also answered in case signal delivery raced  in fanotify_get_response()
260 		spin_unlock(&group->notification_lock);  in fanotify_get_response()
265 	switch (event->response & ~FAN_AUDIT) {  in fanotify_get_response()
271 		ret = -EPERM;  in fanotify_get_response()
275 	if (event->response & FAN_AUDIT)  in fanotify_get_response()
276 		audit_fanotify(event->response & ~FAN_AUDIT);  in fanotify_get_response()
278 	pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__,  in fanotify_get_response()
279 		 group, event, ret);  in fanotify_get_response()
281 	fsnotify_destroy_event(group, &event->fae.fse);  in fanotify_get_response()
292 static u32 fanotify_group_event_mask(struct fsnotify_group *group,  in fanotify_group_event_mask()  argument
302 	unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);  in fanotify_group_event_mask()
308 		 __func__, iter_info->report_mask, event_mask, data, data_type);  in fanotify_group_event_mask()
315 		if (!d_is_reg(path->dentry) && !d_can_lookup(path->dentry))  in fanotify_group_event_mask()
333 		if (!fsnotify_mask_applicable(mark->mask, ondir, type))  in fanotify_group_event_mask()
336 		marks_mask |= mark->mask;  in fanotify_group_event_mask()
338 		/* Record the mark types of this group that matched the event */  in fanotify_group_event_mask()
354 	 * fanotify_alloc_event() when group is reporting fid as indication  in fanotify_group_event_mask()
408 	void *buf = fh->buf;  in fanotify_encode_fh()
411 	fh->type = FILEID_ROOT;  in fanotify_encode_fh()
412 	fh->len = 0;  in fanotify_encode_fh()
413 	fh->flags = 0;  in fanotify_encode_fh()
427 	err = -ENOENT;  in fanotify_encode_fh()
434 		err = -ENOMEM;  in fanotify_encode_fh()
441 		fh->flags |= FANOTIFY_FH_FLAG_EXT_BUF;  in fanotify_encode_fh()
446 	err = -EINVAL;  in fanotify_encode_fh()
450 	fh->type = type;  in fanotify_encode_fh()
451 	fh->len = fh_len;  in fanotify_encode_fh()
469 	fh->type = FILEID_INVALID;  in fanotify_encode_fh()
470 	fh->len = 0;  in fanotify_encode_fh()
492  * and the group flags.
494  * With the group flag FAN_REPORT_TARGET_FID, always report the child fid.
496  * Without the group flag FAN_REPORT_TARGET_FID, report the modified directory
531 	if (inode && S_ISDIR(inode->i_mode))  in fanotify_dfid_inode()
547 	pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH;  in fanotify_alloc_path_event()
548 	pevent->path = *path;  in fanotify_alloc_path_event()
552 	return &pevent->fae;  in fanotify_alloc_path_event()
564 	pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH_PERM;  in fanotify_alloc_perm_event()
565 	pevent->response = 0;  in fanotify_alloc_perm_event()
566 	pevent->state = FAN_EVENT_INIT;  in fanotify_alloc_perm_event()
567 	pevent->path = *path;  in fanotify_alloc_perm_event()
570 	return &pevent->fae;  in fanotify_alloc_perm_event()
584 	ffe->fae.type = FANOTIFY_EVENT_TYPE_FID;  in fanotify_alloc_fid_event()
585 	ffe->fsid = *fsid;  in fanotify_alloc_fid_event()
587 	fanotify_encode_fh(&ffe->object_fh, id, fanotify_encode_fh_len(id),  in fanotify_alloc_fid_event()
590 	return &ffe->fae;  in fanotify_alloc_fid_event()
604 	struct inode *dir2 = moved ? d_inode(moved->d_parent) : NULL;  in fanotify_alloc_name_event()
605 	const struct qstr *name2 = moved ? &moved->d_name : NULL;  in fanotify_alloc_name_event()
609 	unsigned long name_len = name ? name->len : 0;  in fanotify_alloc_name_event()
610 	unsigned long name2_len = name2 ? name2->len : 0;  in fanotify_alloc_name_event()
625 	fne->fae.type = FANOTIFY_EVENT_TYPE_FID_NAME;  in fanotify_alloc_name_event()
626 	fne->fsid = *fsid;  in fanotify_alloc_name_event()
628 	info = &fne->info;  in fanotify_alloc_name_event()
647 		*hash ^= full_name_hash((void *)name_len, name->name, name_len);  in fanotify_alloc_name_event()
651 		*hash ^= full_name_hash((void *)name2_len, name2->name,  in fanotify_alloc_name_event()
657 		 info->name_len, info->name_len, fanotify_info_name(info));  in fanotify_alloc_name_event()
661 			 __func__, dir2_fh_len, info->name2_len,  in fanotify_alloc_name_event()
662 			 info->name2_len, fanotify_info_name2(info));  in fanotify_alloc_name_event()
665 	return &fne->fae;  in fanotify_alloc_name_event()
669 						struct fsnotify_group *group,  in fanotify_alloc_error_event()  argument
683 	fee = mempool_alloc(&group->fanotify_data.error_events_pool, GFP_NOFS);  in fanotify_alloc_error_event()
687 	fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR;  in fanotify_alloc_error_event()
688 	fee->error = report->error;  in fanotify_alloc_error_event()
689 	fee->err_count = 1;  in fanotify_alloc_error_event()
690 	fee->fsid = *fsid;  in fanotify_alloc_error_event()
692 	inode = report->inode;  in fanotify_alloc_error_event()
699 	fanotify_encode_fh(&fee->object_fh, inode, fh_len, NULL, 0);  in fanotify_alloc_error_event()
703 	return &fee->fae;  in fanotify_alloc_error_event()
707 				struct fsnotify_group *group,  in fanotify_alloc_event()  argument
714 	unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);  in fanotify_alloc_event()
729 		 * For certain events and group flags, report the child fid  in fanotify_alloc_event()
738 		 * We record file name only in a group with FAN_REPORT_NAME  in fanotify_alloc_event()
744 		 * For event on non-directory that is reported to parent, we  in fanotify_alloc_event()
796 	if (group->max_events == UINT_MAX)  in fanotify_alloc_event()
802 	old_memcg = set_active_memcg(group->memcg);  in fanotify_alloc_event()
807 		event = fanotify_alloc_error_event(group, fsid, data,  in fanotify_alloc_event()
821 	if (FAN_GROUP_FLAG(group, FAN_REPORT_TID))  in fanotify_alloc_event()
829 	event->pid = pid;  in fanotify_alloc_event()
850 		conn = READ_ONCE(mark->connector);  in fanotify_get_fsid()
854 		if (!(conn->flags & FSNOTIFY_CONN_FLAG_HAS_FSID))  in fanotify_get_fsid()
858 		fsid = conn->fsid;  in fanotify_get_fsid()
870 static void fanotify_insert_event(struct fsnotify_group *group,  in fanotify_insert_event()  argument
874 	unsigned int bucket = fanotify_event_hash_bucket(group, event);  in fanotify_insert_event()
875 	struct hlist_head *hlist = &group->fanotify_data.merge_hash[bucket];  in fanotify_insert_event()
877 	assert_spin_locked(&group->notification_lock);  in fanotify_insert_event()
879 	if (!fanotify_is_hashed_event(event->mask))  in fanotify_insert_event()
882 	pr_debug("%s: group=%p event=%p bucket=%u\n", __func__,  in fanotify_insert_event()
883 		 group, event, bucket);  in fanotify_insert_event()
885 	hlist_add_head(&event->merge_list, hlist);  in fanotify_insert_event()
888 static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,  in fanotify_handle_event()  argument
924 	mask = fanotify_group_event_mask(group, iter_info, &match_mask,  in fanotify_handle_event()
929 	pr_debug("%s: group=%p mask=%x report_mask=%x\n", __func__,  in fanotify_handle_event()
930 		 group, mask, match_mask);  in fanotify_handle_event()
941 	if (FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS)) {  in fanotify_handle_event()
948 	event = fanotify_alloc_event(group, mask, data, data_type, dir,  in fanotify_handle_event()
950 	ret = -ENOMEM;  in fanotify_handle_event()
957 			fsnotify_queue_overflow(group);  in fanotify_handle_event()
961 	fsn_event = &event->fse;  in fanotify_handle_event()
962 	ret = fsnotify_insert_event(group, fsn_event, fanotify_merge,  in fanotify_handle_event()
968 		fsnotify_destroy_event(group, fsn_event);  in fanotify_handle_event()
972 		ret = fanotify_get_response(group, FANOTIFY_PERM(event),  in fanotify_handle_event()
982 static void fanotify_free_group_priv(struct fsnotify_group *group)  in fanotify_free_group_priv()  argument
984 	kfree(group->fanotify_data.merge_hash);  in fanotify_free_group_priv()
985 	if (group->fanotify_data.ucounts)  in fanotify_free_group_priv()
986 		dec_ucount(group->fanotify_data.ucounts,  in fanotify_free_group_priv()
989 	if (mempool_initialized(&group->fanotify_data.error_events_pool))  in fanotify_free_group_priv()
990 		mempool_exit(&group->fanotify_data.error_events_pool);  in fanotify_free_group_priv()
1009 	if (fanotify_fh_has_ext_buf(&ffe->object_fh))  in fanotify_free_fid_event()
1010 		kfree(fanotify_fh_ext_buf(&ffe->object_fh));  in fanotify_free_fid_event()
1019 static void fanotify_free_error_event(struct fsnotify_group *group,  in fanotify_free_error_event()  argument
1024 	mempool_free(fee, &group->fanotify_data.error_events_pool);  in fanotify_free_error_event()
1027 static void fanotify_free_event(struct fsnotify_group *group,  in fanotify_free_event()  argument
1033 	put_pid(event->pid);  in fanotify_free_event()
1034 	switch (event->type) {  in fanotify_free_event()
1051 		fanotify_free_error_event(group, event);  in fanotify_free_event()
1059 				  struct fsnotify_group *group)  in fanotify_freeing_mark()  argument
1061 	if (!FAN_GROUP_FLAG(group, FAN_UNLIMITED_MARKS))  in fanotify_freeing_mark()
1062 		dec_ucount(group->fanotify_data.ucounts, UCOUNT_FANOTIFY_MARKS);  in fanotify_freeing_mark()