From 5287b07f6d7cc366528954e2c3cae22e47cb76a4 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 2 Oct 2020 10:38:16 -0700 Subject: fs/kernel_read_file: Split into separate source file These routines are used in places outside of exec(2), so in preparation for refactoring them, move them into a separate source file, fs/kernel_read_file.c. Signed-off-by: Kees Cook Reviewed-by: Mimi Zohar Reviewed-by: Luis Chamberlain Acked-by: Scott Branden Link: https://lore.kernel.org/r/20201002173828.2099543-5-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman --- fs/exec.c | 132 -------------------------------------------------------------- 1 file changed, 132 deletions(-) (limited to 'fs/exec.c') diff --git a/fs/exec.c b/fs/exec.c index c454af329413..9f094406ea82 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -950,138 +950,6 @@ struct file *open_exec(const char *name) } EXPORT_SYMBOL(open_exec); -int kernel_read_file(struct file *file, void **buf, loff_t *size, - loff_t max_size, enum kernel_read_file_id id) -{ - loff_t i_size, pos; - ssize_t bytes = 0; - void *allocated = NULL; - int ret; - - if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0) - return -EINVAL; - - ret = deny_write_access(file); - if (ret) - return ret; - - ret = security_kernel_read_file(file, id); - if (ret) - goto out; - - i_size = i_size_read(file_inode(file)); - if (i_size <= 0) { - ret = -EINVAL; - goto out; - } - if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { - ret = -EFBIG; - goto out; - } - - if (!*buf) - *buf = allocated = vmalloc(i_size); - if (!*buf) { - ret = -ENOMEM; - goto out; - } - - pos = 0; - while (pos < i_size) { - bytes = kernel_read(file, *buf + pos, i_size - pos, &pos); - if (bytes < 0) { - ret = bytes; - goto out_free; - } - - if (bytes == 0) - break; - } - - if (pos != i_size) { - ret = -EIO; - goto out_free; - } - - ret = security_kernel_post_read_file(file, *buf, i_size, id); - if (!ret) - *size = pos; - -out_free: - if (ret < 0) { - if (allocated) { - vfree(*buf); - *buf = NULL; - } - } - -out: - allow_write_access(file); - return ret; -} -EXPORT_SYMBOL_GPL(kernel_read_file); - -int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, - loff_t max_size, enum kernel_read_file_id id) -{ - struct file *file; - int ret; - - if (!path || !*path) - return -EINVAL; - - file = filp_open(path, O_RDONLY, 0); - if (IS_ERR(file)) - return PTR_ERR(file); - - ret = kernel_read_file(file, buf, size, max_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, - loff_t *size, loff_t max_size, - enum kernel_read_file_id id) -{ - struct file *file; - struct path root; - int ret; - - if (!path || !*path) - return -EINVAL; - - task_lock(&init_task); - get_fs_root(init_task.fs, &root); - task_unlock(&init_task); - - file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0); - path_put(&root); - if (IS_ERR(file)) - return PTR_ERR(file); - - ret = kernel_read_file(file, buf, size, max_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, loff_t *size, loff_t max_size, - enum kernel_read_file_id id) -{ - struct fd f = fdget(fd); - int ret = -EBADF; - - if (!f.file) - goto out; - - ret = kernel_read_file(f.file, buf, size, max_size, id); -out: - fdput(f); - return ret; -} -EXPORT_SYMBOL_GPL(kernel_read_file_from_fd); - #if defined(CONFIG_HAVE_AOUT) || defined(CONFIG_BINFMT_FLAT) || \ defined(CONFIG_BINFMT_ELF_FDPIC) ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len) -- cgit v1.2.3