diff options
| author | David Disseldorp <ddiss@suse.de> | 2022-05-09 18:29:20 -0700 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-05-09 18:29:20 -0700 |
| commit | 800c24dc34b93d2014f3952683f8d5e9309e1b73 (patch) | |
| tree | 4c93bda186b6636f6054909d065322298ac2add4 /init | |
| parent | ea8048719a0c46d95e6ab925bf0924e7198d9971 (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.c | 29 |
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; |