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grub2/SOURCES/0295-relocator-Protect-grub...

148 lines
4.8 KiB

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexey Makhalov <amakhalov@vmware.com>
Date: Wed, 15 Jul 2020 06:42:37 +0000
Subject: [PATCH] relocator: Protect grub_relocator_alloc_chunk_addr() input
args against integer underflow/overflow
Use arithmetic macros from safemath.h to accomplish it. In this commit,
I didn't want to be too paranoid to check every possible math equation
for overflow/underflow. Only obvious places (with non zero chance of
overflow/underflow) were refactored.
Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Upstream-commit-id: ebb15735f10
---
grub-core/loader/i386/linux.c | 9 +++++++--
grub-core/loader/i386/pc/linux.c | 9 +++++++--
grub-core/loader/i386/xen.c | 12 ++++++++++--
grub-core/loader/xnu.c | 11 +++++++----
4 files changed, 31 insertions(+), 10 deletions(-)
diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c
index 76304f057..b4a30f607 100644
--- a/grub-core/loader/i386/linux.c
+++ b/grub-core/loader/i386/linux.c
@@ -37,6 +37,7 @@
#include <grub/linux.h>
#include <grub/efi/sb.h>
#include <grub/tpm.h>
+#include <grub/safemath.h>
GRUB_MOD_LICENSE ("GPLv3+");
@@ -593,9 +594,13 @@ grub_linux_boot (void)
{
grub_relocator_chunk_t ch;
+ grub_size_t sz;
+
+ if (grub_add (ctx.real_size, efi_mmap_size, &sz))
+ return GRUB_ERR_OUT_OF_RANGE;
+
err = grub_relocator_alloc_chunk_addr (relocator, &ch,
- ctx.real_mode_target,
- (ctx.real_size + efi_mmap_size));
+ ctx.real_mode_target, sz);
if (err)
return err;
real_mode_mem = get_virtual_current_address (ch);
diff --git a/grub-core/loader/i386/pc/linux.c b/grub-core/loader/i386/pc/linux.c
index 783a3cd93..540891371 100644
--- a/grub-core/loader/i386/pc/linux.c
+++ b/grub-core/loader/i386/pc/linux.c
@@ -36,6 +36,7 @@
#include <grub/lib/cmdline.h>
#include <grub/linux.h>
#include <grub/efi/sb.h>
+#include <grub/safemath.h>
GRUB_MOD_LICENSE ("GPLv3+");
@@ -231,8 +232,12 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
setup_sects = GRUB_LINUX_DEFAULT_SETUP_SECTS;
real_size = setup_sects << GRUB_DISK_SECTOR_BITS;
- grub_linux16_prot_size = grub_file_size (file)
- - real_size - GRUB_DISK_SECTOR_SIZE;
+ if (grub_sub (grub_file_size (file), real_size, &grub_linux16_prot_size) ||
+ grub_sub (grub_linux16_prot_size, GRUB_DISK_SECTOR_SIZE, &grub_linux16_prot_size))
+ {
+ grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected"));
+ goto fail;
+ }
if (! grub_linux_is_bzimage
&& GRUB_LINUX_ZIMAGE_ADDR + grub_linux16_prot_size
diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
index 3073f64d5..85b93347b 100644
--- a/grub-core/loader/i386/xen.c
+++ b/grub-core/loader/i386/xen.c
@@ -40,6 +40,7 @@
#include <grub/xen_file.h>
#include <grub/linux.h>
#include <grub/i386/memory.h>
+#include <grub/safemath.h>
GRUB_MOD_LICENSE ("GPLv3+");
@@ -635,6 +636,7 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
grub_relocator_chunk_t ch;
grub_addr_t kern_start;
grub_addr_t kern_end;
+ grub_size_t sz;
if (argc == 0)
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
@@ -699,8 +701,14 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
xen_state.max_addr = ALIGN_UP (kern_end, PAGE_SIZE);
- err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch, kern_start,
- kern_end - kern_start);
+
+ if (grub_sub (kern_end, kern_start, &sz))
+ {
+ err = GRUB_ERR_OUT_OF_RANGE;
+ goto fail;
+ }
+
+ err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch, kern_start, sz);
if (err)
goto fail;
kern_chunk_src = get_virtual_current_address (ch);
diff --git a/grub-core/loader/xnu.c b/grub-core/loader/xnu.c
index dc7d5409e..2bf02489b 100644
--- a/grub-core/loader/xnu.c
+++ b/grub-core/loader/xnu.c
@@ -34,6 +34,7 @@
#include <grub/env.h>
#include <grub/i18n.h>
#include <grub/efi/sb.h>
+#include <grub/safemath.h>
GRUB_MOD_LICENSE ("GPLv3+");
@@ -59,15 +60,17 @@ grub_xnu_heap_malloc (int size, void **src, grub_addr_t *target)
{
grub_err_t err;
grub_relocator_chunk_t ch;
+ grub_addr_t tgt;
+
+ if (grub_add (grub_xnu_heap_target_start, grub_xnu_heap_size, &tgt))
+ return GRUB_ERR_OUT_OF_RANGE;
- err = grub_relocator_alloc_chunk_addr (grub_xnu_relocator, &ch,
- grub_xnu_heap_target_start
- + grub_xnu_heap_size, size);
+ err = grub_relocator_alloc_chunk_addr (grub_xnu_relocator, &ch, tgt, size);
if (err)
return err;
*src = get_virtual_current_address (ch);
- *target = grub_xnu_heap_target_start + grub_xnu_heap_size;
+ *target = tgt;
grub_xnu_heap_size += size;
grub_dprintf ("xnu", "val=%p\n", *src);
return GRUB_ERR_NONE;