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author | Jakub Kicinski <kuba@kernel.org> | 2020-07-09 17:42:44 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-07-10 13:54:00 -0700 |
commit | a2b992c828f7651db369ba8f0eb0818d70232636 (patch) | |
tree | f66e1c6eeb40d7acf38ad802e80df4efdde2e2f3 /fs | |
parent | 8fb49c0109f47e4a25e8ba36abd8381afbfa7a08 (diff) | |
download | linux-stable-a2b992c828f7651db369ba8f0eb0818d70232636.tar.gz linux-stable-a2b992c828f7651db369ba8f0eb0818d70232636.tar.bz2 linux-stable-a2b992c828f7651db369ba8f0eb0818d70232636.zip |
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.c | 27 |
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); |