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base/SOURCES/0314-relocator-Protect-grub...

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From 940b7872052d8539c7699e6323fda9467c87f67c Mon Sep 17 00:00:00 2001
From: Alexey Makhalov <amakhalov@vmware.com>
Date: Wed, 8 Jul 2020 01:44:38 +0000
Subject: [PATCH 314/336] relocator: Protect grub_relocator_alloc_chunk_align()
max_addr against integer underflow
This commit introduces integer underflow mitigation in max_addr calculation
in grub_relocator_alloc_chunk_align() invocation.
It consists of 2 fixes:
1. Introduced grub_relocator_alloc_chunk_align_safe() wrapper function to perform
sanity check for min/max and size values, and to make safe invocation of
grub_relocator_alloc_chunk_align() with validated max_addr value. Replace all
invocations such as grub_relocator_alloc_chunk_align(..., min_addr, max_addr - size, size, ...)
by grub_relocator_alloc_chunk_align_safe(..., min_addr, max_addr, size, ...).
2. Introduced UP_TO_TOP32(s) macro for the cases where max_addr is 32-bit top
address (0xffffffff - size + 1) or similar.
Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Upstream-commit-id: 10498c8ba17
---
grub-core/lib/i386/relocator.c | 28 ++++++++++----------------
grub-core/lib/mips/relocator.c | 6 ++----
grub-core/lib/powerpc/relocator.c | 6 ++----
grub-core/loader/i386/linux.c | 5 ++---
grub-core/loader/i386/multiboot_mbi.c | 7 +++----
grub-core/loader/i386/pc/linux.c | 6 ++----
grub-core/loader/mips/linux.c | 9 +++------
grub-core/loader/multiboot.c | 2 +-
grub-core/loader/multiboot_elfxx.c | 5 ++---
grub-core/loader/multiboot_mbi2.c | 11 ++++++----
grub-core/loader/xnu_resume.c | 2 +-
include/grub/relocator.h | 29 +++++++++++++++++++++++++++
12 files changed, 65 insertions(+), 51 deletions(-)
diff --git a/grub-core/lib/i386/relocator.c b/grub-core/lib/i386/relocator.c
index ffaf25f088d..08f6821f20c 100644
--- a/grub-core/lib/i386/relocator.c
+++ b/grub-core/lib/i386/relocator.c
@@ -84,11 +84,10 @@ grub_relocator32_boot (struct grub_relocator *rel,
/* Specific memory range due to Global Descriptor Table for use by payload
that we will store in returned chunk. The address range and preference
are based on "THE LINUX/x86 BOOT PROTOCOL" specification. */
- err = grub_relocator_alloc_chunk_align (rel, &ch, 0x1000,
- 0x9a000 - RELOCATOR_SIZEOF (32),
- RELOCATOR_SIZEOF (32), 16,
- GRUB_RELOCATOR_PREFERENCE_LOW,
- avoid_efi_bootservices);
+ err = grub_relocator_alloc_chunk_align_safe (rel, &ch, 0x1000, 0x9a000,
+ RELOCATOR_SIZEOF (32), 16,
+ GRUB_RELOCATOR_PREFERENCE_LOW,
+ avoid_efi_bootservices);
if (err)
return err;
@@ -126,13 +125,10 @@ grub_relocator16_boot (struct grub_relocator *rel,
grub_relocator_chunk_t ch;
/* Put it higher than the byte it checks for A20 check. */
- err = grub_relocator_alloc_chunk_align (rel, &ch, 0x8010,
- 0xa0000 - RELOCATOR_SIZEOF (16)
- - GRUB_RELOCATOR16_STACK_SIZE,
- RELOCATOR_SIZEOF (16)
- + GRUB_RELOCATOR16_STACK_SIZE, 16,
- GRUB_RELOCATOR_PREFERENCE_NONE,
- 0);
+ err = grub_relocator_alloc_chunk_align_safe (rel, &ch, 0x8010, 0xa0000,
+ RELOCATOR_SIZEOF (16) +
+ GRUB_RELOCATOR16_STACK_SIZE, 16,
+ GRUB_RELOCATOR_PREFERENCE_NONE, 0);
if (err)
return err;
@@ -184,11 +180,9 @@ grub_relocator64_boot (struct grub_relocator *rel,
void *relst;
grub_relocator_chunk_t ch;
- err = grub_relocator_alloc_chunk_align (rel, &ch, min_addr,
- max_addr - RELOCATOR_SIZEOF (64),
- RELOCATOR_SIZEOF (64), 16,
- GRUB_RELOCATOR_PREFERENCE_NONE,
- 0);
+ err = grub_relocator_alloc_chunk_align_safe (rel, &ch, min_addr, max_addr,
+ RELOCATOR_SIZEOF (64), 16,
+ GRUB_RELOCATOR_PREFERENCE_NONE, 0);
if (err)
return err;
diff --git a/grub-core/lib/mips/relocator.c b/grub-core/lib/mips/relocator.c
index 9d5f49cb93a..743b213e695 100644
--- a/grub-core/lib/mips/relocator.c
+++ b/grub-core/lib/mips/relocator.c
@@ -120,10 +120,8 @@ grub_relocator32_boot (struct grub_relocator *rel,
unsigned i;
grub_addr_t vtarget;
- err = grub_relocator_alloc_chunk_align (rel, &ch, 0,
- (0xffffffff - stateset_size)
- + 1, stateset_size,
- sizeof (grub_uint32_t),
+ err = grub_relocator_alloc_chunk_align (rel, &ch, 0, UP_TO_TOP32 (stateset_size),
+ stateset_size, sizeof (grub_uint32_t),
GRUB_RELOCATOR_PREFERENCE_NONE, 0);
if (err)
return err;
diff --git a/grub-core/lib/powerpc/relocator.c b/grub-core/lib/powerpc/relocator.c
index bdf2b111be7..8ffb8b68683 100644
--- a/grub-core/lib/powerpc/relocator.c
+++ b/grub-core/lib/powerpc/relocator.c
@@ -115,10 +115,8 @@ grub_relocator32_boot (struct grub_relocator *rel,
unsigned i;
grub_relocator_chunk_t ch;
- err = grub_relocator_alloc_chunk_align (rel, &ch, 0,
- (0xffffffff - stateset_size)
- + 1, stateset_size,
- sizeof (grub_uint32_t),
+ err = grub_relocator_alloc_chunk_align (rel, &ch, 0, UP_TO_TOP32 (stateset_size),
+ stateset_size, sizeof (grub_uint32_t),
GRUB_RELOCATOR_PREFERENCE_NONE, 0);
if (err)
return err;
diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c
index 1a36979a5ec..8531ca17437 100644
--- a/grub-core/loader/i386/linux.c
+++ b/grub-core/loader/i386/linux.c
@@ -230,9 +230,8 @@ allocate_pages (grub_size_t prot_size, grub_size_t *align,
for (; err && *align + 1 > min_align; (*align)--)
{
grub_errno = GRUB_ERR_NONE;
- err = grub_relocator_alloc_chunk_align (relocator, &ch,
- 0x1000000,
- 0xffffffff & ~prot_size,
+ err = grub_relocator_alloc_chunk_align (relocator, &ch, 0x1000000,
+ UP_TO_TOP32 (prot_size),
prot_size, 1 << *align,
GRUB_RELOCATOR_PREFERENCE_LOW,
1);
diff --git a/grub-core/loader/i386/multiboot_mbi.c b/grub-core/loader/i386/multiboot_mbi.c
index f10c087f724..adda5fd3a87 100644
--- a/grub-core/loader/i386/multiboot_mbi.c
+++ b/grub-core/loader/i386/multiboot_mbi.c
@@ -445,10 +445,9 @@ grub_multiboot_make_mbi (grub_uint32_t *target)
bufsize = grub_multiboot_get_mbi_size ();
- err = grub_relocator_alloc_chunk_align (grub_multiboot_relocator, &ch,
- 0x10000, 0xa0000 - bufsize,
- bufsize, 4,
- GRUB_RELOCATOR_PREFERENCE_NONE, 0);
+ err = grub_relocator_alloc_chunk_align_safe (grub_multiboot_relocator, &ch,
+ 0x10000, 0xa0000, bufsize, 4,
+ GRUB_RELOCATOR_PREFERENCE_NONE, 0);
if (err)
return err;
ptrorig = get_virtual_current_address (ch);
diff --git a/grub-core/loader/i386/pc/linux.c b/grub-core/loader/i386/pc/linux.c
index 4a801a7ab08..f217f5071b6 100644
--- a/grub-core/loader/i386/pc/linux.c
+++ b/grub-core/loader/i386/pc/linux.c
@@ -457,10 +457,8 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
{
grub_relocator_chunk_t ch;
- err = grub_relocator_alloc_chunk_align (relocator, &ch,
- addr_min, addr_max - size,
- size, 0x1000,
- GRUB_RELOCATOR_PREFERENCE_HIGH, 0);
+ err = grub_relocator_alloc_chunk_align_safe (relocator, &ch, addr_min, addr_max, size,
+ 0x1000, GRUB_RELOCATOR_PREFERENCE_HIGH, 0);
if (err)
return err;
initrd_chunk = get_virtual_current_address (ch);
diff --git a/grub-core/loader/mips/linux.c b/grub-core/loader/mips/linux.c
index 4a3e8c5dfa2..f4bfd1d8b20 100644
--- a/grub-core/loader/mips/linux.c
+++ b/grub-core/loader/mips/linux.c
@@ -434,12 +434,9 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
{
grub_relocator_chunk_t ch;
- err = grub_relocator_alloc_chunk_align (relocator, &ch,
- (target_addr & 0x1fffffff)
- + linux_size + 0x10000,
- (0x10000000 - size),
- size, 0x10000,
- GRUB_RELOCATOR_PREFERENCE_NONE, 0);
+ err = grub_relocator_alloc_chunk_align_safe (relocator, &ch, (target_addr & 0x1fffffff) +
+ linux_size + 0x10000, 0x10000000, size,
+ 0x10000, GRUB_RELOCATOR_PREFERENCE_NONE, 0);
if (err)
goto fail;
diff --git a/grub-core/loader/multiboot.c b/grub-core/loader/multiboot.c
index e4e696e8f89..e2d3a8b5b2e 100644
--- a/grub-core/loader/multiboot.c
+++ b/grub-core/loader/multiboot.c
@@ -343,7 +343,7 @@ grub_cmd_module (grub_command_t cmd __attribute__ ((unused)),
{
grub_relocator_chunk_t ch;
err = grub_relocator_alloc_chunk_align (grub_multiboot_relocator, &ch,
- lowest_addr, (0xffffffff - size) + 1,
+ lowest_addr, UP_TO_TOP32 (size),
size, MULTIBOOT_MOD_ALIGN,
GRUB_RELOCATOR_PREFERENCE_NONE, 1);
if (err)
diff --git a/grub-core/loader/multiboot_elfxx.c b/grub-core/loader/multiboot_elfxx.c
index c0ff1239dbf..6d87f08976f 100644
--- a/grub-core/loader/multiboot_elfxx.c
+++ b/grub-core/loader/multiboot_elfxx.c
@@ -201,9 +201,8 @@ CONCAT(grub_multiboot_load_elf, XX) (grub_file_t file, const char *filename, voi
grub_relocator_chunk_t ch;
err = grub_relocator_alloc_chunk_align (grub_multiboot_relocator,
&ch, 0,
- (0xffffffff - sh->sh_size)
- + 1, sh->sh_size,
- sh->sh_addralign,
+ UP_TO_TOP32 (sh->sh_size),
+ sh->sh_size, sh->sh_addralign,
GRUB_RELOCATOR_PREFERENCE_NONE,
0);
if (err)
diff --git a/grub-core/loader/multiboot_mbi2.c b/grub-core/loader/multiboot_mbi2.c
index 7e01dfb5ee7..e99d3177a4a 100644
--- a/grub-core/loader/multiboot_mbi2.c
+++ b/grub-core/loader/multiboot_mbi2.c
@@ -235,15 +235,18 @@ grub_multiboot_load (grub_file_t file, const char *filename)
grub_size_t code_size;
void *source;
grub_relocator_chunk_t ch;
+ int preference = GRUB_RELOCATOR_PREFERENCE_NONE;
if (addr_tag->bss_end_addr)
code_size = (addr_tag->bss_end_addr - load_addr);
else
code_size = load_size;
- err = grub_relocator_alloc_chunk_addr (grub_multiboot_relocator,
- &ch, load_addr,
- code_size);
+ err = grub_relocator_alloc_chunk_align_safe (grub_multiboot_relocator,
+ &ch, load_addr,
+ UP_TO_TOP32(load_addr),
+ code_size, 0, preference,
+ keep_bs);
if (err)
{
grub_dprintf ("multiboot_loader", "Error loading aout kludge\n");
@@ -647,7 +650,7 @@ grub_multiboot_make_mbi (grub_uint32_t *target)
COMPILE_TIME_ASSERT (MULTIBOOT_TAG_ALIGN % sizeof (grub_properly_aligned_t) == 0);
err = grub_relocator_alloc_chunk_align (grub_multiboot_relocator, &ch,
- 0, 0xffffffff - bufsize,
+ 0, UP_TO_TOP32 (bufsize),
bufsize, MULTIBOOT_TAG_ALIGN,
GRUB_RELOCATOR_PREFERENCE_NONE, 1);
if (err)
diff --git a/grub-core/loader/xnu_resume.c b/grub-core/loader/xnu_resume.c
index 534a74438b2..99119558d21 100644
--- a/grub-core/loader/xnu_resume.c
+++ b/grub-core/loader/xnu_resume.c
@@ -129,7 +129,7 @@ grub_xnu_resume (char *imagename)
{
grub_relocator_chunk_t ch;
err = grub_relocator_alloc_chunk_align (grub_xnu_relocator, &ch, 0,
- (0xffffffff - hibhead.image_size) + 1,
+ UP_TO_TOP32 (hibhead.image_size),
hibhead.image_size,
GRUB_XNU_PAGESIZE,
GRUB_RELOCATOR_PREFERENCE_NONE, 0);
diff --git a/include/grub/relocator.h b/include/grub/relocator.h
index 24d8672d22c..1b3bdd92ac6 100644
--- a/include/grub/relocator.h
+++ b/include/grub/relocator.h
@@ -49,6 +49,35 @@ grub_relocator_alloc_chunk_align (struct grub_relocator *rel,
int preference,
int avoid_efi_boot_services);
+/*
+ * Wrapper for grub_relocator_alloc_chunk_align() with purpose of
+ * protecting against integer underflow.
+ *
+ * Compare to its callee, max_addr has different meaning here.
+ * It covers entire chunk and not just start address of the chunk.
+ */
+static inline grub_err_t
+grub_relocator_alloc_chunk_align_safe (struct grub_relocator *rel,
+ grub_relocator_chunk_t *out,
+ grub_phys_addr_t min_addr,
+ grub_phys_addr_t max_addr,
+ grub_size_t size, grub_size_t align,
+ int preference,
+ int avoid_efi_boot_services)
+{
+ /* Sanity check and ensure following equation (max_addr - size) is safe. */
+ if (max_addr < size || (max_addr - size) < min_addr)
+ return GRUB_ERR_OUT_OF_RANGE;
+
+ return grub_relocator_alloc_chunk_align (rel, out, min_addr,
+ max_addr - size,
+ size, align, preference,
+ avoid_efi_boot_services);
+}
+
+/* Top 32-bit address minus s bytes and plus 1 byte. */
+#define UP_TO_TOP32(s) ((~(s) & 0xffffffff) + 1)
+
#define GRUB_RELOCATOR_PREFERENCE_NONE 0
#define GRUB_RELOCATOR_PREFERENCE_LOW 1
#define GRUB_RELOCATOR_PREFERENCE_HIGH 2
--
2.26.2