From 7c79eddbec32d8258df701d95d8b432f9835110b Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 4 Nov 2020 09:59:14 -0700 Subject: [PATCH] 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 Reviewed-by: Bin Meng --- arch/x86/lib/zimage.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/lib/zimage.c b/arch/x86/lib/zimage.c index 7418c9a5fe..d425ded596 100644 --- a/arch/x86/lib/zimage.c +++ b/arch/x86/lib/zimage.c @@ -31,6 +31,7 @@ #include #endif #include +#include #include /* @@ -175,11 +176,19 @@ static const char *get_kernel_version(struct boot_params *params, { struct setup_header *hdr = ¶ms->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; } -- 2.39.5