From 04dd17822334871b23ea2862f7798fb0e0007777 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 11 May 2024 08:53:19 +0000
Subject: [PATCH] change otg to host mode

---
 kernel/fs/notify/fanotify/fanotify_user.c |   22 ++++++++++++++++++++--
 1 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/kernel/fs/notify/fanotify/fanotify_user.c b/kernel/fs/notify/fanotify/fanotify_user.c
index 18e014f..84de9f9 100644
--- a/kernel/fs/notify/fanotify/fanotify_user.c
+++ b/kernel/fs/notify/fanotify/fanotify_user.c
@@ -1090,8 +1090,11 @@
 	return 0;
 }
 
-static int fanotify_events_supported(struct path *path, __u64 mask)
+static int fanotify_events_supported(struct path *path, __u64 mask,
+				     unsigned int flags)
 {
+	unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
+
 	/*
 	 * Some filesystems such as 'proc' acquire unusual locks when opening
 	 * files. For them fanotify permission events have high chances of
@@ -1103,6 +1106,21 @@
 	if (mask & FANOTIFY_PERM_EVENTS &&
 	    path->mnt->mnt_sb->s_type->fs_flags & FS_DISALLOW_NOTIFY_PERM)
 		return -EINVAL;
+
+	/*
+	 * mount and sb marks are not allowed on kernel internal pseudo fs,
+	 * like pipe_mnt, because that would subscribe to events on all the
+	 * anonynous pipes in the system.
+	 *
+	 * SB_NOUSER covers all of the internal pseudo fs whose objects are not
+	 * exposed to user's mount namespace, but there are other SB_KERNMOUNT
+	 * fs, like nsfs, debugfs, for which the value of allowing sb and mount
+	 * mark is questionable. For now we leave them alone.
+	 */
+	if (mark_type != FAN_MARK_INODE &&
+	    path->mnt->mnt_sb->s_flags & SB_NOUSER)
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -1218,7 +1236,7 @@
 		goto fput_and_out;
 
 	if (flags & FAN_MARK_ADD) {
-		ret = fanotify_events_supported(&path, mask);
+		ret = fanotify_events_supported(&path, mask, flags);
 		if (ret)
 			goto path_put_and_out;
 	}

--
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