Messages in this thread | | | Subject | Re: [PATCH 05/13] fs/kernel_read_file: Split into separate source file | From | Scott Branden <> | Date | Fri, 17 Jul 2020 12:11:24 -0700 |
| |
On 2020-07-17 10:43 a.m., Kees Cook wrote: > 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 <keescook@chromium.org> Acked-by: Scott Branden <scott.branden@broadcom.com> > --- > fs/Makefile | 3 +- > fs/exec.c | 132 ---------------------------------------- > fs/kernel_read_file.c | 138 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 140 insertions(+), 133 deletions(-) > create mode 100644 fs/kernel_read_file.c > > diff --git a/fs/Makefile b/fs/Makefile > index 2ce5112b02c8..a05fc247b2a7 100644 > --- a/fs/Makefile > +++ b/fs/Makefile > @@ -13,7 +13,8 @@ obj-y := open.o read_write.o file_table.o super.o \ > seq_file.o xattr.o libfs.o fs-writeback.o \ > pnode.o splice.o sync.o utimes.o d_path.o \ > stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \ > - fs_types.o fs_context.o fs_parser.o fsopen.o > + fs_types.o fs_context.o fs_parser.o fsopen.o \ > + kernel_read_file.o > > ifeq ($(CONFIG_BLOCK),y) > obj-y += buffer.o block_dev.o direct-io.o mpage.o > diff --git a/fs/exec.c b/fs/exec.c > index 07a7fe9ac5be..d619b79aab30 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -923,138 +923,6 @@ 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) > diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c > new file mode 100644 > index 000000000000..54d972d4befc > --- /dev/null > +++ b/fs/kernel_read_file.c > @@ -0,0 +1,138 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +#include <linux/fs.h> > +#include <linux/fs_struct.h> > +#include <linux/kernel_read_file.h> > +#include <linux/security.h> > +#include <linux/vmalloc.h> > + > +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);
| |