x86: zimage: Sanity-check the kernel version before printing it

With Chrome OS the kernel setup block is stored in a separate place from
the kernel, so it is not possible to access the kernel version string.
At present, garbage is printed.

Add a sanity check to avoid this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass 2020-11-04 09:59:14 -07:00 committed by Bin Meng
parent b73d61a556
commit 7c79eddbec

View file

@ -31,6 +31,7 @@
#include <asm/arch/timestamp.h>
#endif
#include <linux/compiler.h>
#include <linux/ctype.h>
#include <linux/libfdt.h>
/*
@ -175,11 +176,19 @@ static const char *get_kernel_version(struct boot_params *params,
{
struct setup_header *hdr = &params->hdr;
int bootproto;
const char *s, *end;
bootproto = get_boot_protocol(hdr, false);
if (bootproto < 0x0200 || hdr->setup_sects < 15)
return NULL;
/* sanity-check the kernel version in case it is missing */
for (s = kernel_base + hdr->kernel_version + 0x200, end = s + 0x100; *s;
s++) {
if (!isprint(*s))
return NULL;
}
return kernel_base + hdr->kernel_version + 0x200;
}