284 Commits

Author SHA1 Message Date
Jeremy Szu
cd96802190 loader/i386/linux: Correct wrong initrd address for debug
The "addr" is used to request the memory with specific ranges but the real
loadable address come from the relocator. Thus, print the final retrieved
addresses, virtual and physical, for initrd.

On the occasion migrate to PRIxGRUB_ADDR and PRIxGRUB_SIZE format specifiers.

Signed-off-by: Jeremy Szu <jeremy.szu@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2023-02-28 13:24:38 +01:00
Jeremy Szu
012fe7f055 loader/i386/linux: Fix initrd maximum address overflow
The current i386 initrd is limited under 1 GiB memory and it works with
most compressed initrds (also initrd_addr_max case reported by kernel).

addr = (addr_max - aligned_size) & ~0xFFF;

Above line is used to calculate the reasonable address to store the initrd.

However, if initrd size is greater than 1 GiB or initrd_addr_max, then it
will get overflow, especially on x86_64 arch.

Therefore, add a check point to prevent it overflows as well as having
a debug log for complex story of initrd addresses.

Signed-off-by: Jeremy Szu <jeremy.szu@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-12-07 23:38:26 +01:00
Ross Philipson
170f17734a loader/i386/bsd: Initialize BSD relocator state variables
Numerous register fields in the relocator state are simply not
used depending on the relocator. This causes Coverity to flag
these fields but there is no real bug here. Simply initializing
the variable to {0} solves the issue. Fixed in the else case too
for consistency.

Fixes: CID 396932

Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-10-04 14:46:56 +02:00
Nikita Ermakov
5730424cb9 loader: Drop argv[] argument in grub_initrd_load()
In the case of an error grub_initrd_load() uses argv[] to print the
filename that caused the error. It is also possible to obtain the
filename from the file handles and there is no need to duplicate that
information in argv[], so let's drop it.

Signed-off-by: Nikita Ermakov <arei@altlinux.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-08-19 23:55:49 +02:00
Alec Brown
8df6e1c067 loader: Update error conditionals to use enums
In grub-core/loader/i386/bsdXX.c and grub-core/loader/multiboot_elfxx.c, error
conditionals are simplified to statements such as "if (err)". Even though the
assumption that non-zero values give errors is correct, it would be clearer and
more consistent to compare these conditionals to GRUB_ERR_NONE.

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-08-19 22:37:21 +02:00
Alec Brown
ddb6c1bafb elf: Validate number of elf program header table entries
In bsdXX.c and multiboot_elfxx.c, e_phnum is used to obtain the number of
program header table entries, but it wasn't being checked if the value was
there.

According to the elf(5) manual page,
"If the number of entries in the program header table is larger than or equal to
PN_XNUM (0xffff), this member holds PN_XNUM (0xffff) and the real number of
entries in the program header table is held in the sh_info member of the
initial entry in section header table.  Otherwise, the sh_info member of the
initial entry contains the value zero."

Since this check wasn't being made, grub_elfXX_get_phnum() is being added to
elfXX.c to make this check and use e_phnum if it doesn't have PN_XNUM as a
value, else use sh_info. We also need to make sure e_phnum isn't greater than
PN_XNUM and sh_info isn't less than PN_XNUM.

Note that even though elf.c and elfXX.c are located in grub-core/kern, they are
compiled as modules and don't need the EXPORT_FUNC() macro to define the functions
in elf.h.

Also, changed casts of phnum to match variables being set as well as dropped
casts when unnecessary.

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-08-19 22:27:51 +02:00
Alec Brown
27a14a8ae2 elf: Validate number of elf section header table entries
In bsdXX.c and multiboot_elfxx.c, e_shnum is used to obtain the number of
section header table entries, but it wasn't being checked if the value was
there.

According to the elf(5) manual page,
"If the number of entries in the section header table is larger than or equal to
SHN_LORESERVE (0xff00), e_shnum holds the value zero and the real number of
entries in the section header table is held in the sh_size member of the initial
entry in section header table. Otherwise, the sh_size member of the initial
entry in the section header table holds the value zero."

Since this check wasn't being made, grub_elfXX_get_shnum() is being added to
elfXX.c to make this check and use whichever member doesn't have a value of
zero. If both are zero, then we must return an error. We also need to make sure
that e_shnum doesn't have a value greater than or equal to SHN_LORESERVE and
sh_size isn't less than SHN_LORESERVE.

In order to get this function to work, the type ElfXX_Shnum is being added where
Elf32_Shnum defines Elf32_Word and Elf64_Shnum defines Elf64_Xword. This new
type is needed because if shnum obtains a value from sh_size, sh_size could be
of type El32_Word for Elf32_Shdr structures or Elf64_Xword for Elf64_Shdr
structures.

Note that even though elf.c and elfXX.c are located in grub-core/kern, they are
compiled as modules and don't need the EXPORT_FUNC() macro to define the functions
in elf.h.

For a few smaller changes, changed casts of shnum to match variables being set
as well as dropped casts when unnecessary and fixed spacing errors in bsdXX.c.
Also, shnum is an unsigned integer and is compared to int i in multiboot_elfxx.c,
it should be unsigned to match shnum.

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-08-19 22:26:35 +02:00
Alec Brown
253da39c15 grub-core/loader/i386/bsdXX: Avoid downcasting (char *) to (Elf_Shdr *)
In bsdXX.c, a couple of untrusted loop bound and untrusted allocation size bugs
were flagged by Coverity in the functions grub_openbsd_find_ramdisk() and
grub_freebsd_load_elfmodule(). These bugs were flagged by coverity because the
variable shdr was downcasting from a char pointer to an Elf_Shdr pointer
whenever it was used to set the base value in for loops. To avoid this, we need
to set shdr as an Elf_Shdr pointer where it is initialized.

In the function read_headers(), the function is reading elf section header data
from a file and passing it to the variable shdr as data for a char pointer. If
we switch the type of shdr to an Elf_Shdr pointer in read_headers() as well as
other functions, then we won't need to downcast to an Elf_Shdr pointer. By doing
this, the issue becomes masked from Coverity's view. In the following patches,
we check limits to ensure the data isn't tainted.

Also, switched use of (char *) to (grub_uint8_t *) to give a better indication
of pointer arithmetic and not suggest use of a C string.

Fixes: CID 314018
Fixes: CID 314030
Fixes: CID 314031
Fixes: CID 314039

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
2022-06-07 13:48:23 +02:00
Michael Chang
acffb81485 build: Fix -Werror=array-bounds array subscript 0 is outside array bounds
The GRUB is failing to build with GCC-12 in many places like this:

  In function 'init_cbfsdisk',
      inlined from 'grub_mod_init' at ../../grub-core/fs/cbfs.c:391:3:
  ../../grub-core/fs/cbfs.c:345:7: error: array subscript 0 is outside array bounds of 'grub_uint32_t[0]' {aka 'unsigned int[]'} [-Werror=array-bounds]
    345 |   ptr = *(grub_uint32_t *) 0xfffffffc;
        |   ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is caused by GCC regression in 11/12 [1]. In a nut shell, the
warning is about detected invalid accesses at non-zero offsets to NULL
pointers. Since hardwired constant address is treated as NULL plus an
offset in the same underlying code, the warning is therefore triggered.

Instead of inserting #pragma all over the places where literal pointers
are accessed to avoid diagnosing array-bounds, we can try to borrow the
idea from Linux kernel that the absolute_pointer() macro [2][3] is used
to disconnect a pointer using literal address from it's original object,
hence GCC won't be able to make assumptions on the boundary while doing
pointer arithmetic. With that we can greatly reduce the code we have to
cover up by making initial literal pointer assignment to use the new
wrapper but not having to track everywhere literal pointers are
accessed. This also makes code looks cleaner.

Please note the grub_absolute_pointer() macro requires to be invoked in
a function as long as it is compound expression. Some global variables
with literal pointers has been changed to local ones in order to use
grub_absolute_pointer() to initialize it. The shuffling is basically done
in a selective and careful way that the variable's scope doesn't matter
being local or global, for example, the global variable must not get
modified at run time throughout. For the record, here's the list of
global variables got shuffled in this patch:

  grub-core/commands/i386/pc/drivemap.c:int13slot
  grub-core/term/i386/pc/console.c:bios_data_area
  grub-core/term/ns8250.c:serial_hw_io_addr

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578
[2] https://elixir.bootlin.com/linux/v5.16.14/source/include/linux/compiler.h#L180
[3] https://elixir.bootlin.com/linux/v5.16.14/source/include/linux/compiler-gcc.h#L31

Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-04-20 18:27:52 +02:00
Alec Brown
a97d1ebb8e loader/i386/xnu: Fix uninitialized scalar variable
In the function grub_xnu_boot(), struct grub_relocator32_state state is called
but isn't being initialized. This results in the members grub_uint32_t ebx,
grub_uint32_t ecx, grub_uint32_t edx, grub_uint32_t edi, and grub_uint32_t esi
being filled with junk data from the stack since none of them are being set to
any values. We can prevent this by setting state to {0}.

Fixes: CID 375035

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-04-04 20:28:55 +02:00
Alec Brown
4fa5dd08f5 loader/i386/xnu: Fix uninitialized scalar variable
In the function grub_xnu_boot_resume(), struct grub_relocator32_state state is
called but isn't being initialized. This results in the members grub_uint32_t
ebx, grub_uint32_t ecx, grub_uint32_t edx, grub_uint32_t esi, and grub_uint32_t
edi being filled with junk data from the stack since none of them are being set
to any values. We can prevent this by setting state to {0}.

Fixes: CID 375031

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-04-04 20:28:55 +02:00
Alec Brown
261e4511ce loader/i386/pc/linux: Fix uninitialized scalar variable
In the function grub_linux16_boot(), struct grub_relocator16_state state is
called but isn't being initialized. This results in the members grub_uint32_t
ebx, grub_uint32_t edx, grub_uint32_t esi, and grub_uint32_t ebp being filled
with junk data from the stack since none of them are being set to any values.
We can prevent this by setting state to {0}.

Fixes: CID 375028

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-04-04 20:28:54 +02:00
Alec Brown
c0272c12b6 loader/i386/bsd: Fix uninitialized scalar variable
In the function grub_netbsd_setup_video(), struct grub_netbsd_btinfo_framebuf
params is called but isn't being initialized. The member grub_uint8_t
reserved[16] isn't set to any values and is instead filled with junk data from
the stack. We can prevent this by setting params to {0}.

Fixes: CID 375026

Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-04-04 20:28:54 +02:00
Daniel Kiper
093ac51dc6 loader/i386/bsd: Initialize ptr variable in grub_bsd_add_meta()
Latest GCC may complain in that way:

  In file included from ../include/grub/disk.h:31,
                   from ../include/grub/file.h:26,
                   from ../include/grub/loader.h:23,
                   from loader/i386/bsd.c:19:
  loader/i386/bsd.c: In function ‘grub_cmd_openbsd’:
  ../include/grub/misc.h:71:10: error: ‘ptr’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
     71 |   return grub_memmove (dest, src, n);
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~
  loader/i386/bsd.c:266:9: note: ‘ptr’ was declared here
    266 |   void *ptr;
        |         ^~~

So, let's fix it by assigning NULL to ptr in grub_bsd_add_meta().

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Robbie Harwood <rharwood@redhat.com>
2022-03-14 23:05:00 +01:00
Elyes Haouas
6a4d9e859e loader: Remove trailing whitespaces
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-03-14 15:47:32 +01:00
Glenn Washburn
5625825434 loader/i386/pc/linux: Use PRI* macros to get correct format string code across architectures
Also remove casting of format string args so that the architecture dependent
type is preserved.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-10 14:59:26 +01:00
Glenn Washburn
e96c7645f4 grub_error: Use format code PRIuGRUB_SIZE for variables of type grub_size_t
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-10 14:50:44 +01:00
Tianjia Zhang
8fcfd1e0fc loader/i386/linux: Do not use grub_le_to_cpu32() for relocatable variable
The relocatable variable is defined as grub_uint8_t. Relevant
member in setup_header structure is also defined as one byte
in Linux boot protocol. By semantic definition it is a bool type.
It is not appropriate to treat it as a four bytes. This patch
fixes the issue.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 17:46:13 +01:00
Tianjia Zhang
2bcf005298 loader/i386/linux: Remove redundant code from in grub_cmd_linux()
The preferred_address has been assigned to GRUB_LINUX_BZIMAGE_ADDR
during initialization in grub_cmd_linux(). The assignment here
is redundant and should be removed.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 17:41:32 +01:00
Darren Kenny
5d5391b0a0 loader/bsd: Check for NULL arg up-front
The code in the next block suggests that it is possible for .set to be
true but .arg may still be NULL.

This code assumes that it is never NULL, yet later is testing if it is
NULL - that is inconsistent.

So we should check first if .arg is not NULL, and remove this check that
is being flagged by Coverity since it is no longer required.

Fixes: CID 292471

Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:17 +01:00
Daniel Kiper
a195dbb677 loader/linux: Report the UEFI Secure Boot status to the Linux kernel
Now that the GRUB has a grub_efi_get_secureboot() function to check the
UEFI Secure Boot status, use it to report that to the Linux kernel.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-12-12 01:19:03 +01:00
Peter Jones
d2cf823d0e efi: Fix some malformed device path arithmetic errors
Several places we take the length of a device path and subtract 4 from
it, without ever checking that it's >= 4. There are also cases where
this kind of malformation will result in unpredictable iteration,
including treating the length from one dp node as the type in the next
node. These are all errors, no matter where the data comes from.

This patch adds a checking macro, GRUB_EFI_DEVICE_PATH_VALID(), which
can be used in several places, and makes GRUB_EFI_NEXT_DEVICE_PATH()
return NULL and GRUB_EFI_END_ENTIRE_DEVICE_PATH() evaluate as true when
the length is too small. Additionally, it makes several places in the
code check for and return errors in these cases.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:48 +02:00
Alexey Makhalov
61ff5602fe 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>
2020-07-29 16:55:48 +02:00
Alexey Makhalov
caea56d1f8 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>
2020-07-29 16:55:48 +02:00
Alexey Makhalov
6d7a59a2a1 xnu: Fix double free in grub_xnu_devprop_add_property()
grub_xnu_devprop_add_property() should not free utf8 and utf16 as it get
allocated and freed in the caller.

Minor improvement: do prop fields initialization after memory allocations.

Fixes: CID 292442, CID 292457, CID 292460, CID 292466

Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:48 +02:00
Peter Jones
3f05d693d1 malloc: Use overflow checking primitives where we do complex allocations
This attempts to fix the places where we do the following where
arithmetic_expr may include unvalidated data:

  X = grub_malloc(arithmetic_expr);

It accomplishes this by doing the arithmetic ahead of time using grub_add(),
grub_sub(), grub_mul() and testing for overflow before proceeding.

Among other issues, this fixes:
  - allocation of integer overflow in grub_video_bitmap_create()
    reported by Chris Coulson,
  - allocation of integer overflow in grub_png_decode_image_header()
    reported by Chris Coulson,
  - allocation of integer overflow in grub_squash_read_symlink()
    reported by Chris Coulson,
  - allocation of integer overflow in grub_ext2_read_symlink()
    reported by Chris Coulson,
  - allocation of integer overflow in read_section_as_string()
    reported by Chris Coulson.

Fixes: CVE-2020-14309, CVE-2020-14310, CVE-2020-14311

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:47 +02:00
Peter Jones
f725fa7cb2 calloc: Use calloc() at most places
This modifies most of the places we do some form of:

  X = malloc(Y * Z);

to use calloc(Y, Z) instead.

Among other issues, this fixes:
  - allocation of integer overflow in grub_png_decode_image_header()
    reported by Chris Coulson,
  - allocation of integer overflow in luks_recover_key()
    reported by Chris Coulson,
  - allocation of integer overflow in grub_lvm_detect()
    reported by Chris Coulson.

Fixes: CVE-2020-14308

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-07-29 16:55:47 +02:00
Peter Jones
d5a32255de misc: Make grub_strtol() "end" pointers have safer const qualifiers
Currently the string functions grub_strtol(), grub_strtoul(), and
grub_strtoull() don't declare the "end" pointer in such a way as to
require the pointer itself or the character array to be immutable to the
implementation, nor does the C standard do so in its similar functions,
though it does require us not to change any of it.

The typical declarations of these functions follow this pattern:

long
strtol(const char * restrict nptr, char ** restrict endptr, int base);

Much of the reason for this is historic, and a discussion of that
follows below, after the explanation of this change.  (GRUB currently
does not include the "restrict" qualifiers, and we name the arguments a
bit differently.)

The implementation is semantically required to treat the character array
as immutable, but such accidental modifications aren't stopped by the
compiler, and the semantics for both the callers and the implementation
of these functions are sometimes also helped by adding that requirement.

This patch changes these declarations to follow this pattern instead:

long
strtol(const char * restrict nptr,
       const char ** const restrict endptr,
       int base);

This means that if any modification to these functions accidentally
introduces either an errant modification to the underlying character
array, or an accidental assignment to endptr rather than *endptr, the
compiler should generate an error.  (The two uses of "restrict" in this
case basically mean strtol() isn't allowed to modify the character array
by going through *endptr, and endptr isn't allowed to point inside the
array.)

It also means the typical use case changes to:

  char *s = ...;
  const char *end;
  long l;

  l = strtol(s, &end, 10);

Or even:

  const char *p = str;
  while (p && *p) {
	  long l = strtol(p, &p, 10);
	  ...
  }

This fixes 26 places where we discard our attempts at treating the data
safely by doing:

  const char *p = str;
  long l;

  l = strtol(p, (char **)&ptr, 10);

It also adds 5 places where we do:

  char *p = str;
  while (p && *p) {
	  long l = strtol(p, (const char ** const)&p, 10);
	  ...
	  /* more calls that need p not to be pointer-to-const */
  }

While moderately distasteful, this is a better problem to have.

With one minor exception, I have tested that all of this compiles
without relevant warnings or errors, and that /much/ of it behaves
correctly, with gcc 9 using 'gcc -W -Wall -Wextra'.  The one exception
is the changes in grub-core/osdep/aros/hostdisk.c , which I have no idea
how to build.

Because the C standard defined type-qualifiers in a way that can be
confusing, in the past there's been a slow but fairly regular stream of
churn within our patches, which add and remove the const qualifier in many
of the users of these functions.  This change should help avoid that in
the future, and in order to help ensure this, I've added an explanation
in misc.h so that when someone does get a compiler warning about a type
error, they have the fix at hand.

The reason we don't have "const" in these calls in the standard is
purely anachronistic: C78 (de facto) did not have type qualifiers in the
syntax, and the "const" type qualifier was added for C89 (I think; it
may have been later).  strtol() appears to date from 4.3BSD in 1986,
which means it could not be added to those functions in the standard
without breaking compatibility, which is usually avoided.

The syntax chosen for type qualifiers is what has led to the churn
regarding usage of const, and is especially confusing on string
functions due to the lack of a string type.  Quoting from C99, the
syntax is:

 declarator:
  pointer[opt] direct-declarator
 direct-declarator:
  identifier
  ( declarator )
  direct-declarator [ type-qualifier-list[opt] assignment-expression[opt] ]
  ...
  direct-declarator [ type-qualifier-list[opt] * ]
  ...
 pointer:
  * type-qualifier-list[opt]
  * type-qualifier-list[opt] pointer
 type-qualifier-list:
  type-qualifier
  type-qualifier-list type-qualifier
 ...
 type-qualifier:
  const
  restrict
  volatile

So the examples go like:

const char foo;			// immutable object
const char *foo;		// mutable pointer to object
char * const foo;		// immutable pointer to mutable object
const char * const foo;		// immutable pointer to immutable object
const char const * const foo; 	// XXX extra const keyword in the middle
const char * const * const foo; // immutable pointer to immutable
				//   pointer to immutable object
const char ** const foo;	// immutable pointer to mutable pointer
				//   to immutable object

Making const left-associative for * and right-associative for everything
else may not have been the best choice ever, but here we are, and the
inevitable result is people using trying to use const (as they should!),
putting it at the wrong place, fighting with the compiler for a bit, and
then either removing it or typecasting something in a bad way.  I won't
go into describing restrict, but its syntax has exactly the same issue
as with const.

Anyway, the last example above actually represents the *behavior* that's
required of strtol()-like functions, so that's our choice for the "end"
pointer.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-02-28 12:41:29 +01:00
Daniel Kiper
b53a2f2c66 loader/i386/linux: Fix an underflow in the setup_header length calculation
Recent work around x86 Linux kernel loader revealed an underflow in the
setup_header length calculation and another related issue. Both lead to
the memory overwrite and later machine crash.

Currently when the GRUB copies the setup_header into the linux_params
(struct boot_params, traditionally known as "zero page") it assumes the
setup_header size as sizeof(linux_i386_kernel_header/lh). This is
incorrect. It should use the value calculated accordingly to the Linux
kernel boot protocol. Otherwise in case of pretty old kernel, to be
exact Linux kernel boot protocol, the GRUB may write more into
linux_params than it was expected to. Fortunately this is not very big
issue. Though it has to be fixed. However, there is also an underflow
which is grave. It happens when

  sizeof(linux_i386_kernel_header/lh) > "real size of the setup_header".

Then len value wraps around and grub_file_read() reads whole kernel into
the linux_params overwriting memory past it. This leads to the GRUB
memory allocator breakage and finally to its crash during boot.

The patch fixes both issues. Additionally, it moves the code not related to
grub_memset(linux_params)/grub_memcpy(linux_params)/grub_file_read(linux_params)
section outside of it to not confuse the reader.

Fixes: e683cfb0cf5 (loader/i386/linux: Calculate the setup_header length)

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Krystian Hebel <krystian.hebel@3mdeb.com>
2019-12-20 20:35:21 +01:00
Vladimir Serbinenko
ad4bfeec5c Change fs functions to add fs_ prefix
This avoid conflict with gnulib

Signed-off-by: Vladimir Serbinenko <phcoder@google.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2019-04-09 10:03:29 +10:00
Andrew Jeddeloh
e683cfb0cf loader/i386/linux: Calculate the setup_header length
Previously the setup_header length was just assumed to be the size of the
linux_kernel_params struct. The linux x86 32-bit boot protocol says that the
end of the linux_i386_kernel_header is at 0x202 + the byte value at 0x201 in
the linux_i386_kernel_header. So, calculate the size of the header using the
end of the linux_i386_kernel_header, rather than assume it is the size of the
linux_kernel_params struct.

Additionally, add some required members to the linux_kernel_params
struct and align the content of linux_i386_kernel_header struct with
it. New members naming was taken directly from Linux kernel source.

linux_kernel_params and linux_i386_kernel_header structs require more
cleanup. However, this is not urgent, so, let's do this after release.
Just in case...

Signed-off-by: Andrew Jeddeloh <andrew.jeddeloh@coreos.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Vladimir Serbinenko <phcoder@google.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
2019-04-02 13:09:54 +02:00
Marek Marczykowski-Górecki
67580c0068 xen: Look for Xen notes in section headers too
Mirror behaviour of ELF loader in libxc: first look for Xen notes in
PT_NOTE segment, then in SHT_NOTE section and only then fallback to
a section with __xen_guest name. This fixes loading PV kernels that
Xen note have outside of PT_NOTE. While this may be result of a buggy
linker script, loading such kernel directly works fine, so make it work
with GRUB too. Specifically, this applies to binaries built from Unikraft.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2019-03-19 11:38:29 +01:00
Juergen Gross
0b3e4eb2d2 xen: Add basic hooks for PVH in current code
Add the hooks to current code needed for Xen PVH. They will be filled
with code later when the related functionality is being added.

loader/i386/linux.c needs to include machine/kernel.h now as it needs
to get GRUB_KERNEL_USE_RSDP_ADDR from there. This in turn requires to
add an empty kernel.h header for some i386 platforms (efi, coreboot,
ieee1275, xen) and for x86_64 efi.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
2018-12-12 12:03:27 +01:00
Juergen Gross
d170be42f1 loader/linux: Support passing RSDP address via boot params
Xen PVH guests will have the RSDP at an arbitrary address. Support that
by passing the RSDP address via the boot parameters to Linux.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
2018-12-12 12:03:27 +01:00
Daniel Kiper
e5b846333f verifiers: Xen fallout cleanup
Xen fallout cleanup after commit ca0a4f689 (verifiers: File type for
fine-grained signature-verification controlling).

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
2018-12-07 11:59:23 +01:00
Vladimir Serbinenko
4d4a8c96e3 verifiers: Add possibility to verify kernel and modules command lines
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
2018-11-09 13:25:31 +01:00
Vladimir Serbinenko
ca0a4f689a verifiers: File type for fine-grained signature-verification controlling
Let's provide file type info to the I/O layer. This way verifiers
framework and its users will be able to differentiate files and verify
only required ones.

This is preparatory patch.

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
2018-11-09 13:25:31 +01:00
Cao jin
5d7d13ce44 linux16: Code cleanup
1. move relocator related code more close to each other
2. use variable "len" since it has correct assignment, and keep coding
style with upper code

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2018-09-13 10:51:34 +02:00
Leif Lindholm
ad2bebc6fc loader/i386/linux: Use central copy of grub_efi_find_mmap_size()
Delete local copy of function to determine required buffer size for the
UEFI memory map, use helper in kern/efi/mm.c.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2018-09-12 12:58:31 +02:00
Arindam Nath
886edba877 i386/linux: Add support for ext_lfb_base
The EFI Graphics Output Protocol can return a 64-bit
linear frame buffer address in some firmware/BIOS
implementations. We currently only store the lower
32-bits in the lfb_base. This will eventually be
passed to Linux kernel and the efifb driver will
incorrectly interpret the framebuffer address as
32-bit address.

The Linux kernel has already added support to handle
64-bit linear framebuffer address in the efifb driver
since quite some time now.

This patch adds the support for 64-bit linear frame
buffer address in GRUB to address the above mentioned
scenario.

Signed-off-by: Arindam Nath <arindam.nath@amd.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2018-07-25 14:18:05 +02:00
C. Masloch
c225298038 chainloader: patch in BPB's sectors_per_track and num_heads
These fields must reflect the ROM-BIOS's geometry for CHS-based
loaders to correctly load their next stage. Most loaders do not
query the ROM-BIOS (Int13.08), relying on the BPB fields to hold
the correct values already.

Tested with lDebug booted in qemu via grub2's
FreeDOS direct loading support, refer to
https://bitbucket.org/ecm/ldosboot + https://bitbucket.org/ecm/ldebug
(For this test, lDebug's iniload.asm must be assembled with
-D_QUERY_GEOMETRY=0 to leave the BPB values provided by grub.)

Signed-off-by: C. Masloch <pushbx@38.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2018-03-14 13:23:27 +01:00
Leif Lindholm
7d36709d5e i386: make struct linux_kernel_header architecture specific
struct linux_kernel_header -> struct linux_i386_kernel_header

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2018-02-23 22:42:42 +01:00
Leif Lindholm
3245f02d9d make GRUB_LINUX_MAGIC_SIGNATURE architecture-specific
Rename GRUB_LINUX_MAGIC_SIGNATURE GRUB_LINUX_I386_MAGIC_SIGNATURE,
to be usable in code that supports more than one image type.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2018-02-23 22:42:42 +01:00
Daniel Kiper
ae2a274518 chainloader: Fix wrong break condition (must be AND not, OR)
The definition of bpb's num_total_sectors_16 and num_total_sectors_32
is that either the 16-bit field is non-zero and is used (in which case
eg mkfs.fat sets the 32-bit field to zero), or it is zero and the
32-bit field is used. Therefore, a BPB is invalid only if *both*
fields are zero; having one field as zero and the other as non-zero is
the case to be expected. (Indeed, according to Microsoft's specification
one of the fields *must* be zero, and the other non-zero.)

This affects all users of grub_chainloader_patch_bpb which are in
chainloader.c, freedos.c, and ntldr.c

Some descriptions of the semantics of these two fields:

https://www.win.tue.nl/~aeb/linux/fs/fat/fat-1.html

  The old 2-byte fields "total number of sectors" and "number of
  sectors per FAT" are now zero; this information is now found in
  the new 4-byte fields.

(Here given in the FAT32 EBPB section but the total sectors 16/32 bit
fields semantic is true of FAT12 and FAT16 too.)

https://wiki.osdev.org/FAT#BPB_.28BIOS_Parameter_Block.29

  19 | 2 | The total sectors in the logical volume. If this value is 0,
  it means there are more than 65535 sectors in the volume, and the actual
  count is stored in "Large Sectors (bytes 32-35).

  32 | 4 | Large amount of sector on media. This field is set if there
  are more than 65535 sectors in the volume.

(Doesn't specify what the "large" field is set to when unused, but as
mentioned mkfs.fat sets it to zero then.)

https://technet.microsoft.com/en-us/library/cc976796.aspx

  0x13 | WORD | 0x0000 |
  Small Sectors . The number of sectors on the volume represented in 16
  bits (< 65,536). For volumes larger than 65,536 sectors, this field
  has a value of zero and the Large Sectors field is used instead.

  0x20 | DWORD | 0x01F03E00 |
  Large Sectors . If the value of the Small Sectors field is zero, this
  field contains the total number of sectors in the FAT16 volume. If the
  value of the Small Sectors field is not zero, the value of this field
  is zero.

https://staff.washington.edu/dittrich/misc/fatgen103.pdf page 10

  BPB_TotSec16 | 19 | 2 |
  This field is the old 16-bit total count of sectors on the volume.
  This count includes the count of all sectors in all four regions of the
  volume. This field can be 0; if it is 0, then BPB_TotSec32 must be
  non-zero. For FAT32 volumes, this field must be 0. For FAT12 and
  FAT16 volumes, this field contains the sector count, and
  BPB_TotSec32 is 0 if the total sector count “fits” (is less than
  0x10000).

  BPB_TotSec32 | 32 | 4 |
  This field is the new 32-bit total count of sectors on the volume.
  This count includes the count of all sectors in all four regions of the
  volume. This field can be 0; if it is 0, then BPB_TotSec16 must be
  non-zero. For FAT32 volumes, this field must be non-zero. For
  FAT12/FAT16 volumes, this field contains the sector count if
  BPB_TotSec16 is 0 (count is greater than or equal to 0x10000).

(This specifies that an unused BPB_TotSec32 field is set to zero.)

By the way fix offsets in include/grub/fat.h.

Tested with lDebug booted in qemu via grub2's
FreeDOS direct loading support, refer to
https://bitbucket.org/ecm/ldosboot + https://bitbucket.org/ecm/ldebug

Signed-off-by: C. Masloch <pushbx@38.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2018-02-23 22:32:55 +01:00
Vladimir Serbinenko
21e4a6fa03 multiboot: disentangle multiboot and multiboot2.
Previously we had multiboot and multiboot2 declaring the same symbols.
This can potentially lead to aliasing and strange behaviours when e.g.
module instead of module2 is used with multiboot2.

Bug: #51137
2017-08-14 14:08:54 +02:00
Vladimir Serbinenko
d454509bb8 Fix remaining cases of gcc 7 fallthrough warning.
They are all intended, so just add the relevant comment.
2017-04-12 01:42:38 +00:00
Andrei Borzenkov
4bd4a88725 i386, x86_64, ppc: fix switch fallthrough cases with GCC7
In util/getroot and efidisk slightly modify exitsing comment to mostly
retain it but still make GCC7 compliant with respect to fall through
annotation.

In grub-core/lib/xzembed/xz_dec_lzma2.c it adds same comments as
upstream.

In grub-core/tests/setjmp_tets.c declare functions as "noreturn" to
suppress GCC7 warning.

In grub-core/gnulib/regexec.c use new __attribute__, because existing
annotation is not recognized by GCC7 parser (which requires that comment
immediately precedes case statement).

Otherwise add FALLTHROUGH comment.

Closes: 50598
2017-04-04 19:23:55 +03:00
Vladimir Serbinenko
529818738f xen: Fix parsing of XZ kernel.
In case of xz, the uncompressed size is appended to xz data which confuses
our xz decompressor. Trim it.
2017-02-07 13:25:38 +01:00
Vladimir Serbinenko
8a96fc4093 xen: Fix handling of GRUB chainloading.
In case of GRUB we put remapper after domain pages and not at 0x0.
In this case we use max_addr to put remapper. Unfortunately we increment
max_addr as well in this case resulting in virt mapping mapping page
at old max_addr and trying to boot using new max_addr.

Closes 46014.
2017-02-07 00:42:43 +01:00
Andrei Borzenkov
972765fe82 linux: fix "vga=XX deprecated" warning for text mode
Arguments were in reverse order which resulted in

text is deprecated. Use set gfxpayload=vga=0 before linux command instead.
2017-01-08 15:52:49 +03:00