Merge tag 'fsnotify_for_v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify updates from Jan Kara:
 "A couple of small fsnotify fixes and cleanups"

* tag 'fsnotify_for_v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fanotify: replace deprecated strcpy in fanotify_info_copy_{name,name2}
  fsnotify: inotify: pass mark connector to fsnotify_recalc_mask()
  fanotify: call fanotify_events_supported() before path_permission() and security_path_notify()
  fanotify: avoid/silence premature LSM capability checks
  inotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails

3 files changed, 28 insertions, 30 deletions

diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 39e60218df7c..a0619e7694d5 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -2,6 +2,7 @@
 #include <linux/fsnotify_backend.h>
 #include <linux/path.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/exportfs.h>
 #include <linux/hashtable.h>
 
@@ -218,7 +219,7 @@ static inline void fanotify_info_copy_name(struct fanotify_info *info,
 		return;
 
 	info->name_len = name->len;
-	strcpy(fanotify_info_name(info), name->name);
+	strscpy(fanotify_info_name(info), name->name, name->len + 1);
 }
 
 static inline void fanotify_info_copy_name2(struct fanotify_info *info,
@@ -228,7 +229,7 @@ static inline void fanotify_info_copy_name2(struct fanotify_info *info,
 		return;
 
 	info->name2_len = name->len;
-	strcpy(fanotify_info_name2(info), name->name);
+	strscpy(fanotify_info_name2(info), name->name, name->len + 1);
 }
 
 /*
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index c2dcb25151de..ae904451dfc0 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -1210,6 +1210,7 @@ static int fanotify_find_path(int dfd, const char __user *filename,
 
 		*path = fd_file(f)->f_path;
 		path_get(path);
+		ret = 0;
 	} else {
 		unsigned int lookup_flags = 0;
 
@@ -1219,22 +1220,7 @@ static int fanotify_find_path(int dfd, const char __user *filename,
 			lookup_flags |= LOOKUP_DIRECTORY;
 
 		ret = user_path_at(dfd, filename, lookup_flags, path);
-		if (ret)
-			goto out;
-	}
-
-	/* you can only watch an inode if you have read permissions on it */
-	ret = path_permission(path, MAY_READ);
-	if (ret) {
-		path_put(path);
-		goto out;
 	}
-
-	ret = security_path_notify(path, mask, obj_type);
-	if (ret)
-		path_put(path);
-
-out:
 	return ret;
 }
 
@@ -1615,17 +1601,18 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 	pr_debug("%s: flags=%x event_f_flags=%x\n",
 		 __func__, flags, event_f_flags);
 
-	if (!capable(CAP_SYS_ADMIN)) {
-		/*
-		 * An unprivileged user can setup an fanotify group with
-		 * limited functionality - an unprivileged group is limited to
-		 * notification events with file handles or mount ids and it
-		 * cannot use unlimited queue/marks.
-		 */
-		if ((flags & FANOTIFY_ADMIN_INIT_FLAGS) ||
-		    !(flags & (FANOTIFY_FID_BITS | FAN_REPORT_MNT)))
-			return -EPERM;
+	/*
+	 * An unprivileged user can setup an fanotify group with limited
+	 * functionality - an unprivileged group is limited to notification
+	 * events with file handles or mount ids and it cannot use unlimited
+	 * queue/marks.
+	 */
+	if (((flags & FANOTIFY_ADMIN_INIT_FLAGS) ||
+	     !(flags & (FANOTIFY_FID_BITS | FAN_REPORT_MNT))) &&
+	    !capable(CAP_SYS_ADMIN))
+		return -EPERM;
 
+	if (!ns_capable_noaudit(&init_user_ns, CAP_SYS_ADMIN)) {
 		/*
 		 * Setting the internal flag FANOTIFY_UNPRIV on the group
 		 * prevents setting mount/filesystem marks on this group and
@@ -1990,8 +1977,8 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
 	 * A user is allowed to setup sb/mount/mntns marks only if it is
 	 * capable in the user ns where the group was created.
 	 */
-	if (!ns_capable(group->user_ns, CAP_SYS_ADMIN) &&
-	    mark_type != FAN_MARK_INODE)
+	if (mark_type != FAN_MARK_INODE &&
+	    !ns_capable(group->user_ns, CAP_SYS_ADMIN))
 		return -EPERM;
 
 	/*
@@ -2057,6 +2044,15 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
 			goto path_put_and_out;
 	}
 
+	/* you can only watch an inode if you have read permissions on it */
+	ret = path_permission(&path, MAY_READ);
+	if (ret)
+		goto path_put_and_out;
+
+	ret = security_path_notify(&path, mask, obj_type);
+	if (ret)
+		goto path_put_and_out;
+
 	if (fid_mode) {
 		ret = fanotify_test_fsid(path.dentry, flags, &__fsid);
 		if (ret)
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 5e1845f2c25d..ed37491c1618 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -573,7 +573,7 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
 
 		/* update the inode with this new fsn_mark */
 		if (dropped || do_inode)
-			fsnotify_recalc_mask(inode->i_fsnotify_marks);
+			fsnotify_recalc_mask(fsn_mark->connector);
 
 	}
 
@@ -621,6 +621,7 @@ static int inotify_new_watch(struct fsnotify_group *group,
 	if (ret) {
 		/* we failed to get on the inode, get off the idr */
 		inotify_remove_from_idr(group, tmp_i_mark);
+		dec_inotify_watches(group->inotify_data.ucounts);
 		goto out_err;
 	}