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kexec: replace call to copy_file_from_fd() with kernel version

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Replace copy_file_from_fd() with kernel_read_file_from_fd().

Two new identifiers named READING_KEXEC_IMAGE and READING_KEXEC_INITRAMFS
are defined for measuring, appraising or auditing the kexec image and
initramfs.

Changelog v3:
- return -EBADF, not -ENOEXEC
- identifier change
- split patch, moving copy_file_from_fd() to a separate patch
- split patch, moving IMA changes to a separate patch
v0:
- use kstat file size type loff_t, not size_t
- Calculate the file hash from the in memory buffer - Dave Young

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Acked-by: Dave Young <dyoung@redhat.com>
This commit is contained in:
Mimi Zohar 2016-01-14 20:59:14 -05:00
parent c6af8efe97
commit b804defe42
2 changed files with 11 additions and 64 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/fs.h
View File

@ -2579,6 +2579,8 @@ extern int do_pipe_flags(int *, int);
enum kernel_read_file_id {
READING_FIRMWARE = 1,
READING_MODULE,
READING_KEXEC_IMAGE,
READING_KEXEC_INITRAMFS,
READING_MAX_ID
};

73
kernel/kexec_file.c
View File

@ -18,6 +18,7 @@
#include <linux/kexec.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/fs.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
#include <linux/syscalls.h>
@ -33,65 +34,6 @@ size_t __weak kexec_purgatory_size = 0;
static int kexec_calculate_store_digests(struct kimage *image);
static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len)
{
struct fd f = fdget(fd);
int ret;
struct kstat stat;
loff_t pos;
ssize_t bytes = 0;
if (!f.file)
return -EBADF;
ret = vfs_getattr(&f.file->f_path, &stat);
if (ret)
goto out;
if (stat.size > INT_MAX) {
ret = -EFBIG;
goto out;
}
/* Don't hand 0 to vmalloc, it whines. */
if (stat.size == 0) {
ret = -EINVAL;
goto out;
}
*buf = vmalloc(stat.size);
if (!*buf) {
ret = -ENOMEM;
goto out;
}
pos = 0;
while (pos < stat.size) {
bytes = kernel_read(f.file, pos, (char *)(*buf) + pos,
stat.size - pos);
if (bytes < 0) {
vfree(*buf);
ret = bytes;
goto out;
}
if (bytes == 0)
break;
pos += bytes;
}
if (pos != stat.size) {
ret = -EBADF;
vfree(*buf);
goto out;
}
*buf_len = pos;
out:
fdput(f);
return ret;
}
/* Architectures can provide this probe function */
int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
unsigned long buf_len)
@ -182,16 +124,17 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
{
int ret = 0;
void *ldata;
loff_t size;
ret = copy_file_from_fd(kernel_fd, &image->kernel_buf,
&image->kernel_buf_len);
ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf,
&size, INT_MAX, READING_KEXEC_IMAGE);
if (ret)
return ret;
image->kernel_buf_len = size;
/* Call arch image probe handlers */
ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
image->kernel_buf_len);
if (ret)
goto out;
@ -206,10 +149,12 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
#endif
/* It is possible that there no initramfs is being loaded */
if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
ret = copy_file_from_fd(initrd_fd, &image->initrd_buf,
&image->initrd_buf_len);
ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf,
&size, INT_MAX,
READING_KEXEC_INITRAMFS);
if (ret)
goto out;
image->initrd_buf_len = size;
}
if (cmdline_len) {