Commit 88535288 authored by Kees Cook's avatar Kees Cook Committed by Greg Kroah-Hartman
Browse files

fs/kernel_read_file: Add file_size output argument 



In preparation for adding partial read support, add an optional output
argument to kernel_read_file*() that reports the file size so callers
can reason more easily about their reading progress.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarMimi Zohar <zohar@linux.ibm.com>
Reviewed-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: default avatarJames Morris <jamorris@linux.microsoft.com>
Acked-by: default avatarScott Branden <scott.branden@broadcom.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-8-keescook@chromium.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 113eeb51

drivers/base/firmware_loader/main.c

+1 −0
Original line number Diff line number Diff line
@@ -500,6 +500,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, 


		/* load firmware files from the mount namespace of init */

		rc = kernel_read_file_from_path_initns(path, &buffer, msize,

						       NULL,

						       READING_FIRMWARE);

		if (rc < 0) {

			if (rc != -ENOENT)

fs/kernel_read_file.c

+13 −6
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 
 *		@buf_size will be ignored)

 * @buf_size	size of buf, if already allocated. If @buf not

 *		allocated, this is the largest size to allocate.

 * @file_size	if non-NULL, the full size of @file will be

 *		written here.

 * @id		the kernel_read_file_id identifying the type of

 *		file contents being read (for LSMs to examine)

 *
@@ -22,7 +24,8 @@ 
 *

 */

int kernel_read_file(struct file *file, void **buf,

		     size_t buf_size, enum kernel_read_file_id id)

		     size_t buf_size, size_t *file_size,

		     enum kernel_read_file_id id)

{

	loff_t i_size, pos;

	ssize_t bytes = 0;
@@ -49,6 +52,8 @@ int kernel_read_file(struct file *file, void **buf, 
		ret = -EFBIG;

		goto out;

	}

	if (file_size)

		*file_size = i_size;



	if (!*buf)

		*buf = allocated = vmalloc(i_size);
@@ -91,7 +96,8 @@ out: 
EXPORT_SYMBOL_GPL(kernel_read_file);



int kernel_read_file_from_path(const char *path, void **buf,

			       size_t buf_size, enum kernel_read_file_id id)

			       size_t buf_size, size_t *file_size,

			       enum kernel_read_file_id id)

{

	struct file *file;

	int ret;
@@ -103,14 +109,14 @@ int kernel_read_file_from_path(const char *path, void **buf, 
	if (IS_ERR(file))

		return PTR_ERR(file);



	ret = kernel_read_file(file, buf, buf_size, id);

	ret = kernel_read_file(file, buf, buf_size, file_size, id);

	fput(file);

	return ret;

}

EXPORT_SYMBOL_GPL(kernel_read_file_from_path);



int kernel_read_file_from_path_initns(const char *path, void **buf,

				      size_t buf_size,

				      size_t buf_size, size_t *file_size,

				      enum kernel_read_file_id id)

{

	struct file *file;
@@ -129,13 +135,14 @@ int kernel_read_file_from_path_initns(const char *path, void **buf, 
	if (IS_ERR(file))

		return PTR_ERR(file);



	ret = kernel_read_file(file, buf, buf_size, id);

	ret = kernel_read_file(file, buf, buf_size, file_size, id);

	fput(file);

	return ret;

}

EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);



int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size,

			     size_t *file_size,

			     enum kernel_read_file_id id)

{

	struct fd f = fdget(fd);
@@ -144,7 +151,7 @@ int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size, 
	if (!f.file)

		goto out;



	ret = kernel_read_file(f.file, buf, buf_size, id);

	ret = kernel_read_file(f.file, buf, buf_size, file_size, id);

out:

	fdput(f);

	return ret;

include/linux/kernel_read_file.h

+4 −0
Original line number Diff line number Diff line
@@ -37,15 +37,19 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) 


int kernel_read_file(struct file *file,

		     void **buf, size_t buf_size,

		     size_t *file_size,

		     enum kernel_read_file_id id);

int kernel_read_file_from_path(const char *path,

			       void **buf, size_t buf_size,

			       size_t *file_size,

			       enum kernel_read_file_id id);

int kernel_read_file_from_path_initns(const char *path,

				      void **buf, size_t buf_size,

				      size_t *file_size,

				      enum kernel_read_file_id id);

int kernel_read_file_from_fd(int fd,

			     void **buf, size_t buf_size,

			     size_t *file_size,

			     enum kernel_read_file_id id);



#endif /* _LINUX_KERNEL_READ_FILE_H */

kernel/kexec_file.c

+2 −2
Original line number Diff line number Diff line
@@ -222,7 +222,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, 
	void *ldata;



	ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,

				       INT_MAX, READING_KEXEC_IMAGE);

				       INT_MAX, NULL, READING_KEXEC_IMAGE);

	if (ret < 0)

		return ret;

	image->kernel_buf_len = ret;
@@ -242,7 +242,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, 
	/* It is possible that there no initramfs is being loaded */

	if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {

		ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,

					       INT_MAX,

					       INT_MAX, NULL,

					       READING_KEXEC_INITRAMFS);

		if (ret < 0)

			goto out;

kernel/module.c

+1 −1
Original line number Diff line number Diff line
@@ -4048,7 +4048,7 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) 
		      |MODULE_INIT_IGNORE_VERMAGIC))

		return -EINVAL;



	err = kernel_read_file_from_fd(fd, &hdr, INT_MAX,

	err = kernel_read_file_from_fd(fd, &hdr, INT_MAX, NULL,

				       READING_MODULE);

	if (err < 0)

		return err;

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