From d616f56d34e2a30a4c9d6574c70b15a6082c0edc Mon Sep 17 00:00:00 2001
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Tue, 4 May 2021 15:13:49 +0200
Subject: [PATCH] debugfs: only accept read attributes for blobs
Blobs can only be read. So, keep only 'read' file attributes because the
others will not work and only confuse users.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20210504131350.46586-1-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/debugfs/file.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index e813acfaa6e8a..54f827339c385 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -980,7 +980,8 @@ static const struct file_operations fops_blob = {
/**
* debugfs_create_blob - create a debugfs file that is used to read a binary blob
* @name: a pointer to a string containing the name of the file to create.
- * @mode: the permission that the file should have
+ * @mode: the read permission that the file should have (other permissions are
+ * masked out)
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the debugfs filesystem.
@@ -1004,7 +1005,7 @@ struct dentry *debugfs_create_blob(const char *name, umode_t mode,
struct dentry *parent,
struct debugfs_blob_wrapper *blob)
{
- return debugfs_create_file_unsafe(name, mode, parent, blob, &fops_blob);
+ return debugfs_create_file_unsafe(name, mode & 0444, parent, blob, &fops_blob);
}
EXPORT_SYMBOL_GPL(debugfs_create_blob);
--
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