From: Kairui Song Date: Wed, 14 Oct 2020 09:24:28 +0000 (+0800) Subject: x86/kexec: Use up-to-dated screen_info copy to fill boot params X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=afc18069a2cb7ead5f86623a5f3d4ad6e21f940d;p=linux.git x86/kexec: Use up-to-dated screen_info copy to fill boot params kexec_file_load() currently reuses the old boot_params.screen_info, but if drivers have change the hardware state, boot_param.screen_info could contain invalid info. For example, the video type might be no longer VGA, or the frame buffer address might be changed. If the kexec kernel keeps using the old screen_info, kexec'ed kernel may attempt to write to an invalid framebuffer memory region. There are two screen_info instances globally available, boot_params.screen_info and screen_info. Later one is a copy, and is updated by drivers. So let kexec_file_load use the updated copy. [ mingo: Tidied up the changelog. ] Signed-off-by: Kairui Song Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20201014092429.1415040-2-kasong@redhat.com --- diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index 57c2ecf431343..ce831f9448e71 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -200,8 +200,7 @@ setup_boot_parameters(struct kimage *image, struct boot_params *params, params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch; /* Copying screen_info will do? */ - memcpy(¶ms->screen_info, &boot_params.screen_info, - sizeof(struct screen_info)); + memcpy(¶ms->screen_info, &screen_info, sizeof(struct screen_info)); /* Fill in memsize later */ params->screen_info.ext_mem_k = 0;