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authorDavid Disseldorp <ddiss@suse.de>2022-05-09 18:29:20 -0700
committerakpm <akpm@linux-foundation.org>2022-05-09 18:29:20 -0700
commit800c24dc34b93d2014f3952683f8d5e9309e1b73 (patch)
tree4c93bda186b6636f6054909d065322298ac2add4 /init
parentea8048719a0c46d95e6ab925bf0924e7198d9971 (diff)
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@suse.de Signed-off-by: David Disseldorp <ddiss@suse.de> Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Martin Wilck <mwilck@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'init')
-rw-r--r--init/initramfs.c29
1 files changed, 24 insertions, 5 deletions
diff --git a/init/initramfs.c b/init/initramfs.c
index b5bfed859fa9..dc84cf756cea 100644
--- a/init/initramfs.c
+++ b/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 *file, const char *p, size_t count,
} 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, name_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;