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authorJakub Kicinski <kuba@kernel.org>2020-07-10 03:42:44 +0300
committerDavid S. Miller <davem@davemloft.net>2020-07-10 23:54:00 +0300
commita2b992c828f7651db369ba8f0eb0818d70232636 (patch)
treef66e1c6eeb40d7acf38ad802e80df4efdde2e2f3 /fs
parent8fb49c0109f47e4a25e8ba36abd8381afbfa7a08 (diff)
downloadlinux-a2b992c828f7651db369ba8f0eb0818d70232636.tar.xz
debugfs: make sure we can remove u32_array files cleanly
debugfs_create_u32_array() allocates a small structure to wrap the data and size information about the array. If users ever try to remove the file this leads to a leak since nothing ever frees this wrapper. That said there are no upstream users of debugfs_create_u32_array() that'd remove a u32 array file (we only have one u32 array user in CMA), so there is no real bug here. Make callers pass a wrapper they allocated. This way the lifetime management of the wrapper is on the caller, and we can avoid the potential leak in debugfs. CC: Chucheng Luo <luochucheng@vivo.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs')
-rw-r--r--fs/debugfs/file.c27
1 files changed, 7 insertions, 20 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index ae49a55bda00..d0ed71f37511 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -918,11 +918,6 @@ struct dentry *debugfs_create_blob(const char *name, umode_t mode,
}
EXPORT_SYMBOL_GPL(debugfs_create_blob);
-struct array_data {
- void *array;
- u32 elements;
-};
-
static size_t u32_format_array(char *buf, size_t bufsize,
u32 *array, int array_size)
{
@@ -943,8 +938,8 @@ static size_t u32_format_array(char *buf, size_t bufsize,
static int u32_array_open(struct inode *inode, struct file *file)
{
- struct array_data *data = inode->i_private;
- int size, elements = data->elements;
+ struct debugfs_u32_array *data = inode->i_private;
+ int size, elements = data->n_elements;
char *buf;
/*
@@ -959,7 +954,7 @@ static int u32_array_open(struct inode *inode, struct file *file)
buf[size] = 0;
file->private_data = buf;
- u32_format_array(buf, size, data->array, data->elements);
+ u32_format_array(buf, size, data->array, data->n_elements);
return nonseekable_open(inode, file);
}
@@ -996,8 +991,7 @@ static const struct file_operations u32_array_fops = {
* @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.
- * @array: u32 array that provides data.
- * @elements: total number of elements in the array.
+ * @array: wrapper struct containing data pointer and size of the array.
*
* This function creates a file in debugfs with the given name that exports
* @array as data. If the @mode variable is so set it can be read from.
@@ -1005,17 +999,10 @@ static const struct file_operations u32_array_fops = {
* Once array is created its size can not be changed.
*/
void debugfs_create_u32_array(const char *name, umode_t mode,
- struct dentry *parent, u32 *array, u32 elements)
+ struct dentry *parent,
+ struct debugfs_u32_array *array)
{
- struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
-
- if (data == NULL)
- return;
-
- data->array = array;
- data->elements = elements;
-
- debugfs_create_file_unsafe(name, mode, parent, data, &u32_array_fops);
+ debugfs_create_file_unsafe(name, mode, parent, array, &u32_array_fops);
}
EXPORT_SYMBOL_GPL(debugfs_create_u32_array);