From df3de9e92c3b0f268b0479c452b4710cf39380ff Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 27 Sep 2018 09:21:55 -0500 Subject: x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one error [ Upstream commit 51fbf14f2528a8c6401290e37f1c893a2412f1d3 ] The only use of KEXEC_BACKUP_SRC_END is as an argument to walk_system_ram_res(): int crash_load_segments(struct kimage *image) { ... walk_system_ram_res(KEXEC_BACKUP_SRC_START, KEXEC_BACKUP_SRC_END, image, determine_backup_region); walk_system_ram_res() expects "start, end" arguments that are inclusive, i.e., the range to be walked includes both the start and end addresses. KEXEC_BACKUP_SRC_END was previously defined as (640 * 1024UL), which is the first address *past* the desired 0-640KB range. Define KEXEC_BACKUP_SRC_END as (640 * 1024UL - 1) so the KEXEC_BACKUP_SRC region is [0-0x9ffff], not [0-0xa0000]. Fixes: dd5f726076cc ("kexec: support for kexec on panic using new system call") Signed-off-by: Bjorn Helgaas Signed-off-by: Borislav Petkov CC: "H. Peter Anvin" CC: Andrew Morton CC: Brijesh Singh CC: Greg Kroah-Hartman CC: Ingo Molnar CC: Lianbo Jiang CC: Takashi Iwai CC: Thomas Gleixner CC: Tom Lendacky CC: Vivek Goyal CC: baiyaowei@cmss.chinamobile.com CC: bhe@redhat.com CC: dan.j.williams@intel.com CC: dyoung@redhat.com CC: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/153805811578.1157.6948388946904655969.stgit@bhelgaas-glaptop.roam.corp.google.com Signed-off-by: Sasha Levin --- arch/x86/include/asm/kexec.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index d2434c1cad05..414f9b52e58e 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -66,7 +66,7 @@ struct kimage; /* Memory to backup during crash kdump */ #define KEXEC_BACKUP_SRC_START (0UL) -#define KEXEC_BACKUP_SRC_END (640 * 1024UL) /* 640K */ +#define KEXEC_BACKUP_SRC_END (640 * 1024UL - 1) /* 640K */ /* * CPU does not save ss and sp on stack if execution is already -- cgit v1.2.3