diff options
| author | Benjamin Gray <bgray@linux.ibm.com> | 2023-03-20 15:08:38 +1100 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2023-04-16 17:37:01 +0900 |
| commit | 5efb685bb3af112038af78a2cdf28f0ffdad45f5 (patch) | |
| tree | 49ea55e7ce2803846e6399e0ccc6d09e3a7bb64d | |
| parent | aa7d233f45b4c549750044c9921f7afcbe50925b (diff) | |
initramfs: Check negative timestamp to prevent broken cpio archive
Similar to commit 4c9d410f32b3 ("initramfs: Check timestamp to prevent
broken cpio archive"), except asserts that the timestamp is
non-negative. This can happen when the KBUILD_BUILD_TIMESTAMP is a value
before UNIX epoch, which may be set when making reproducible builds that
don't want to look like they use a valid date.
While support for dates before 1970 might not be supported, this is more
about preventing undetected CPIO corruption. The printf's use a minimum
length format specifier, and will happily make the field longer than 8
characters if they need to.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Tested-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| -rw-r--r-- | usr/gen_init_cpio.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/usr/gen_init_cpio.c b/usr/gen_init_cpio.c index ee01e40e8bc6..61230532fef1 100644 --- a/usr/gen_init_cpio.c +++ b/usr/gen_init_cpio.c @@ -353,6 +353,12 @@ static int cpio_mkfile(const char *name, const char *location, buf.st_mtime = 0xffffffff; } + if (buf.st_mtime < 0) { + fprintf(stderr, "%s: Timestamp negative, clipping.\n", + location); + buf.st_mtime = 0; + } + if (buf.st_size > 0xffffffff) { fprintf(stderr, "%s: Size exceeds maximum cpio file size\n", location); @@ -602,10 +608,10 @@ int main (int argc, char *argv[]) /* * Timestamps after 2106-02-07 06:28:15 UTC have an ascii hex time_t * representation that exceeds 8 chars and breaks the cpio header - * specification. + * specification. Negative timestamps similarly exceed 8 chars. */ - if (default_mtime > 0xffffffff) { - fprintf(stderr, "ERROR: Timestamp too large for cpio format\n"); + if (default_mtime > 0xffffffff || default_mtime < 0) { + fprintf(stderr, "ERROR: Timestamp out of range for cpio format\n"); exit(1); } |