The patch titled
Subject: initramfs: support cpio extraction with file checksums
has been added to the -mm tree. Its filename is
initramfs-support-cpio-extraction-with-file-checksums.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/initramfs-support-cpio-extraction-with-file-checksums.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/initramfs-support-cpio-extraction-with-file-checksums.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: David Disseldorp <ddiss@xxxxxxx>
Subject: initramfs: support cpio extraction with file checksums
Add support for extraction of checksum-enabled "070702" cpio archives,
specified in Documentation/driver-api/early-userspace/buffer-format.rst.
Fail extraction if the calculated file data checksum doesn't match the
value carried in the header.
Link: https://lkml.kernel.org/r/20220404093429.27570-7-ddiss@xxxxxxx
Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
Suggested-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <christian.brauner@xxxxxxxxxx>
Cc: Martin Wilck <mwilck@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
init/initramfs.c | 29 ++++++++++++++++++++++++-----
1 file changed, 24 insertions(+), 5 deletions(-)
--- a/init/initramfs.c~initramfs-support-cpio-extraction-with-file-checksums
+++ a/init/initramfs.c
@@ -17,8 +17,11 @@
#include <linux/init_syscalls.h>
#include <linux/umh.h>
-static ssize_t __init xwrite(struct file *file, const char *p, size_t count,
- loff_t *pos)
+static __initdata bool csum_present;
+static __initdata u32 io_csum;
+
+static ssize_t __init xwrite(struct file *file, const unsigned char *p,
+ size_t count, loff_t *pos)
{
ssize_t out = 0;
@@ -33,6 +36,13 @@ static ssize_t __init xwrite(struct file
} else if (rv == 0)
break;
+ if (csum_present) {
+ ssize_t i;
+
+ for (i = 0; i < rv; i++)
+ io_csum += p[i];
+ }
+
p += rv;
out += rv;
count -= rv;
@@ -176,15 +186,16 @@ static __initdata unsigned long body_len
static __initdata uid_t uid;
static __initdata gid_t gid;
static __initdata unsigned rdev;
+static __initdata u32 hdr_csum;
static void __init parse_header(char *s)
{
- unsigned long parsed[12];
+ unsigned long parsed[13];
char buf[9];
int i;
buf[8] = '\0';
- for (i = 0, s += 6; i < 12; i++, s += 8) {
+ for (i = 0, s += 6; i < 13; i++, s += 8) {
memcpy(buf, s, 8);
parsed[i] = simple_strtoul(buf, NULL, 16);
}
@@ -199,6 +210,7 @@ static void __init parse_header(char *s)
minor = parsed[8];
rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
name_len = parsed[11];
+ hdr_csum = parsed[12];
}
/* FSM */
@@ -267,7 +279,11 @@ static int __init do_collect(void)
static int __init do_header(void)
{
- if (memcmp(collected, "070701", 6)) {
+ if (!memcmp(collected, "070701", 6)) {
+ csum_present = false;
+ } else if (!memcmp(collected, "070702", 6)) {
+ csum_present = true;
+ } else {
if (memcmp(collected, "070707", 6) == 0)
error("incorrect cpio method used: use -H newc option");
else
@@ -362,6 +378,7 @@ static int __init do_name(void)
if (IS_ERR(wfile))
return 0;
wfile_pos = 0;
+ io_csum = 0;
vfs_fchown(wfile, uid, gid);
vfs_fchmod(wfile, mode);
@@ -394,6 +411,8 @@ static int __init do_copy(void)
do_utime_path(&wfile->f_path, mtime);
fput(wfile);
+ if (csum_present && io_csum != hdr_csum)
+ error("bad data checksum");
eat(body_len);
state = SkipIt;
return 0;
_
Patches currently in -mm which might be from ddiss@xxxxxxx are
initramfs-refactor-do_header-cpio-magic-checks.patch
initramfs-make-dir_entryname-a-flexible-array-member.patch
initramfs-add-initramfs_preserve_mtime-kconfig-option.patch
gen_init_cpio-fix-short-read-file-handling.patch
gen_init_cpio-support-file-checksum-archiving.patch
initramfs-support-cpio-extraction-with-file-checksums.patch
