From a8a3bc2e3277858a7457da15225b08ca65a99b0b Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Tue, 4 Mar 2025 16:57:47 +1100 Subject: [PATCH] initramfs: avoid memcpy for hex header fields newc/crc cpio headers contain a bunch of 8-character hexadecimal fields which we convert via simple_strtoul(), following memcpy() into a zero-terminated stack buffer. The new simple_strntoul() helper allows us to pass in max_chars=8 to avoid zero-termination and memcpy(). Signed-off-by: David Disseldorp Link: https://lore.kernel.org/r/20250304061020.9815-5-ddiss@suse.de Signed-off-by: Christian Brauner --- init/initramfs.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/init/initramfs.c b/init/initramfs.c index 002e83ae12ac..6dd3b02c15d7 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -189,14 +189,11 @@ static __initdata u32 hdr_csum; static void __init parse_header(char *s) { unsigned long parsed[13]; - char buf[9]; int i; - buf[8] = '\0'; - for (i = 0, s += 6; i < 13; i++, s += 8) { - memcpy(buf, s, 8); - parsed[i] = simple_strtoul(buf, NULL, 16); - } + for (i = 0, s += 6; i < 13; i++, s += 8) + parsed[i] = simple_strntoul(s, NULL, 16, 8); + ino = parsed[0]; mode = parsed[1]; uid = parsed[2]; -- 2.50.1