Commit Graph
46 Commits
Author SHA1 Message Date
Daniel Axtens 10c3fc28c9 powerpc: Drop Open Hack'Ware - remove GRUB_IEEE1275_FLAG_NO_ANSI
Open Hack'Ware was the only user.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-10-04 14:30:44 +02:00
Daniel Axtens 935bf8fa02 powerpc: Drop Open Hack'Ware - remove GRUB_IEEE1275_FLAG_CANNOT_INTERPRET
Open Hack'Ware was the only user.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-10-04 14:26:32 +02:00
Daniel Axtens fcf9ff2ac5 powerpc: Drop Open Hack'Ware - remove GRUB_IEEE1275_FLAG_CANNOT_SET_COLORS
Open Hack'Ware was the only user.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-10-04 14:24:35 +02:00
Daniel Axtens 333e63b356 powerpc: Drop Open Hack'Ware - remove GRUB_IEEE1275_FLAG_FORCE_CLAIM
Open Hack'Ware was the only user. It added a lot of complexity.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-10-04 14:16:09 +02:00
Daniel Axtens f9ce538eec powerpc: Drop Open Hack'Ware
Open Hack'Ware was an alternative firmware of powerpc under QEMU.

The last commit to any Open Hack'Ware repo I can find is from 2014 [1].

Open Hack'Ware was used for the QEMU "prep" machine type, which was
deprecated in QEMU in commit 54c86f5a4844 (hw/ppc: deprecate the
machine type 'prep', replaced by '40p') in QEMU v3.1, and had reportedly
been broken for years before without anyone noticing. Support was removed
in February 2020 by commit b2ce76a0730e (hw/ppc/prep: Remove the
deprecated "prep" machine and the OpenHackware BIOS).

Open Hack'Ware's limitations require some messy code in GRUB. This
complexity is not worth carrying any more.

Remove detection of Open Hack'Ware. We will clean up the feature flags
in following commits.

[1]: https://github.com/qemu/openhackware and
     https://repo.or.cz/w/openhackware.git are QEMU submodules. They have
     only small changes on top of OHW v0.4.1, which was imported into
     QEMU SCM in 2010. I can't find anything resembling an official repo
     any more.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-10-04 14:04:04 +02:00
Daniel Axtens 70ecee1e21 ieee1275: Drop HEAP_MAX_ADDR and HEAP_MIN_SIZE constants
The HEAP_MAX_ADDR is confusing. Currently it is set to 32MB, except on
ieee1275 on x86, where it is 64MB.

There is a comment which purports to explain it:

  /* If possible, we will avoid claiming heap above this address, because it
     seems to cause relocation problems with OSes that link at 4 MiB */

This doesn't make a lot of sense when the constants are well above 4MB
already. It was not always this way. Prior to commit 7b5d0fe444
(Increase heap limit) in 2010, HEAP_MAX_SIZE and HEAP_MAX_ADDR were
indeed 4MB. However, when the constants were increased the comment was
left unchanged.

It's been over a decade. It doesn't seem like we have problems with
claims over 4MB on powerpc or x86 ieee1275. The SPARC does things
completely differently and never used the constant.

Drop the constant and the check.

The only use of HEAP_MIN_SIZE was to potentially override the
HEAP_MAX_ADDR check. It is now unused. Remove it too.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-07-22 15:32:51 +02:00
Daniel Axtens e48fc8880d video/fb/fbfill: Use unsigned integers for width/height
Since commit 7ce3259f67 (video/fb/fbfill: Fix potential integer
overflow), clang builds of grub-emu have failed with messages like:

  /usr/bin/ld: libgrubmods.a(libgrubmods_a-fbfill.o): in function `grub_video_fbfill_direct24':
  fbfill.c:(.text+0x28e): undefined reference to `__muloti4'

This appears to be due to a weird quirk in how clang compiles

  grub_mul(dst->mode_info->bytes_per_pixel, width, &rowskip)

which is grub_mul(unsigned int, int, &grub_size_t).

It looks like clang somewhere promotes everything to 128-bit maths
before ultimately reducing down to 64 bit for grub_size_t. I think
this is because width is signed, and indeed converting width to an
unsigned int makes the problem go away.

This conversion also makes more sense generally:
  - the caller of all the fbfill_directN functions is
    grub_video_fb_fill_dispatch() and it takes width and height as
    unsigned ints already,
  - it doesn't make sense to fill a negative width or height.

Convert the width and height arguments and associated loop counters
to unsigned ints.

Fixes: 7ce3259f67 (video/fb/fbfill: Fix potential integer overflow)

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-04-12 16:56:45 +02:00
Daniel Axtens b911884dd7 fs/btrfs: Squash some uninitialized reads
We need to check errors before calling into a function that uses the result.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:19 +01:00
Daniel Axtens b88a82e78c fs/btrfs: Validate the number of stripes/parities in RAID5/6
This prevents a divide by zero if nstripes == nparities, and
also prevents propagation of invalid values if nstripes ends up
less than nparities.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:19 +01:00
Daniel Axtens e18a000738 disk/lvm: Do not allow a LV to be it's own segment's node's LV
This prevents infinite recursion in the diskfilter verification code.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:19 +01:00
Daniel Axtens 7012936847 disk/lvm: Sanitize rlocn->offset to prevent wild read
rlocn->offset is read directly from disk and added to the metadatabuf
pointer to create a pointer to a block of metadata. It's a 64-bit
quantity so as long as you don't overflow you can set subsequent
pointers to point anywhere in memory.

Require that rlocn->offset fits within the metadata buffer size.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:19 +01:00
Daniel Axtens 1155d7dffd disk/lvm: Do not overread metadata
We could reach the end of valid metadata and not realize, leading to
some buffer overreads. Check if we have reached the end and bail.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens db29073fc7 disk/lvm: Do not crash if an expected string is not found
Clean up a bunch of cases where we could have strstr() fail and lead to
us dereferencing NULL.

We'll still leak memory in some cases (loops don't clean up allocations
from earlier iterations if a later iteration fails) but at least we're
not crashing.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 2958695c4c disk/lvm: Bail on missing PV list
There's an if block for the presence of "physical_volumes {", but if
that block is absent, then p remains NULL and a NULL-deref will result
when looking for logical volumes.

It doesn't seem like LVM makes sense without physical volumes, so error
out rather than crashing.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 27a79bf38e disk/lvm: Don't blast past the end of the circular metadata buffer
This catches at least some OOB reads, and it's possible I suppose that
if 2 * mda_size is less than GRUB_LVM_MDA_HEADER_SIZE it might catch some
OOB writes too (although that hasn't showed up as a crash in fuzzing yet).

It's a bit ugly and I'd appreciate better suggestions.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens a8cc95de74 disk/lvm: Don't go beyond the end of the data we read from disk
We unconditionally trusted offset_xl from the LVM label header, even if
it told us that the PV header/disk locations were way off past the end
of the data we read from disk.

Require that the offset be sane, fixing an OOB read and crash.

Fixes: CID 314367, CID 314371

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens b5a2b59cc5 io/gzio: Zero gzio->tl/td in init_dynamic_block() if huft_build() fails
If huft_build() fails, gzio->tl or gzio->td could contain pointers that
are no longer valid. Zero them out.

This prevents a double free when grub_gzio_close() comes through and
attempts to free them again.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 4e76b08f71 io/gzio: Catch missing values in huft_build() and bail
In huft_build(), "v" is a table of values in order of bit length.
The code later (when setting up table entries in "r") assumes that all
elements of this array corresponding to a code are initialized and less
than N_MAX. However, it doesn't enforce this.

With sufficiently manipulated inputs (e.g. from fuzzing), there can be
elements of "v" that are not filled. Therefore a lookup into "e" or "d"
will use an uninitialized value. This can lead to an invalid/OOB read on
those values, often leading to a crash.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 18490336d9 io/gzio: Add init_dynamic_block() clean up if unpacking codes fails
init_dynamic_block() didn't clean up gzio->tl and td in some error
paths. This left td pointing to part of tl. Then in grub_gzio_close(),
when tl was freed the storage for td would also be freed. The code then
attempts to free td explicitly, performing a UAF and then a double free.

Explicitly clean up tl and td in the error paths.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 3334a5e6c8 io/gzio: Bail if gzio->tl/td is NULL
This is an ugly fix that doesn't address why gzio->tl comes to be NULL.
However, it seems to be sufficient to patch up a bunch of NULL derefs.

It would be good to revisit this in future and see if we can have
a cleaner solution that addresses some of the causes of the unexpected
NULL pointers.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens ca5d9ac206 fs/nilfs2: Properly bail on errors in grub_nilfs2_btree_node_lookup()
We just introduced an error return in grub_nilfs2_btree_node_lookup().
Make sure the callers catch it.

At the same time, make sure that grub_nilfs2_btree_node_lookup() always
inits the index pointer passed to it.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 37c0eb05cd fs/nilfs2: Don't search children if provided number is too large
NILFS2 reads the number of children a node has from the node. Unfortunately,
that's not trustworthy. Check if it's beyond what the filesystem permits and
reject it if so.

This blocks some OOB reads. I'm not sure how controllable the read is and what
could be done with invalidly read data later on.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 20ab8cb44b fs/nilfs2: Reject too-large keys
NILFS2 has up to 7 keys, per the data structure. Do not permit array
indices in excess of that.

This catches some OOB reads. I don't know how controllable the invalidly
read data is or if that could be used later in the program.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 223120dd83 fs/jfs: Catch infinite recursion
It's possible with a fuzzed filesystem for JFS to keep getblk()-ing
the same data over and over again, leading to stack exhaustion.

Check if we'd be calling the function with exactly the same data as
was passed in, and if so abort.

I'm not sure what the performance impact of this is and am open to
better ideas.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens bd0cf8148c fs/jfs: Limit the extents that getblk() can consider
getblk() implicitly trusts that treehead->count is an accurate count of
the number of extents. However, that value is read from disk and is not
trustworthy, leading to OOB reads and crashes. I am not sure to what
extent the data read from OOB can influence subsequent program execution.

Require callers to pass in the maximum number of extents for which
they have storage.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens ffd5a46f68 fs/jfs: Do not move to leaf level if name length is negative
Fuzzing JFS revealed crashes where a negative number would be passed
to le_to_cpu16_copy(). There it would be cast to a large positive number
and the copy would read and write off the end of the respective buffers.

Catch this at the top as well as the bottom of the loop.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 8d3ae59dee fs/sfs: Fix over-read of root object name
There's a read of the name of the root object that assumes that the name
is nul-terminated within the root block. This isn't guaranteed - it seems
SFS would require you to read multiple blocks to get a full name in general,
but maybe that doesn't apply to the root object.

Either way, figure out how much space is left in the root block and don't
over-read it. This fixes some OOB reads.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 1c15848838 fs/hfs: Disable under lockdown
HFS has issues such as infinite mutual recursion that are simply too
complex to fix for such a legacy format. So simply do not permit
it to be loaded under lockdown.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 2ca0e5dbcd fs/hfsplus: Don't use uninitialized data on corrupt filesystems
Valgrind identified the following use of uninitialized data:

  ==2782220== Conditional jump or move depends on uninitialised value(s)
  ==2782220==    at 0x42B364: grub_hfsplus_btree_search (hfsplus.c:566)
  ==2782220==    by 0x42B21D: grub_hfsplus_read_block (hfsplus.c:185)
  ==2782220==    by 0x42A693: grub_fshelp_read_file (fshelp.c:386)
  ==2782220==    by 0x42C598: grub_hfsplus_read_file (hfsplus.c:219)
  ==2782220==    by 0x42C598: grub_hfsplus_mount (hfsplus.c:330)
  ==2782220==    by 0x42B8C5: grub_hfsplus_dir (hfsplus.c:958)
  ==2782220==    by 0x4C1AE6: grub_fs_probe (fs.c:73)
  ==2782220==    by 0x407C94: grub_ls_list_files (ls.c:186)
  ==2782220==    by 0x407C94: grub_cmd_ls (ls.c:284)
  ==2782220==    by 0x4D7130: grub_extcmd_dispatcher (extcmd.c:55)
  ==2782220==    by 0x4045A6: execute_command (grub-fstest.c:59)
  ==2782220==    by 0x4045A6: fstest (grub-fstest.c:433)
  ==2782220==    by 0x4045A6: main (grub-fstest.c:772)
  ==2782220==  Uninitialised value was created by a heap allocation
  ==2782220==    at 0x483C7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==2782220==    by 0x4C0305: grub_malloc (mm.c:42)
  ==2782220==    by 0x42C21D: grub_hfsplus_mount (hfsplus.c:239)
  ==2782220==    by 0x42B8C5: grub_hfsplus_dir (hfsplus.c:958)
  ==2782220==    by 0x4C1AE6: grub_fs_probe (fs.c:73)
  ==2782220==    by 0x407C94: grub_ls_list_files (ls.c:186)
  ==2782220==    by 0x407C94: grub_cmd_ls (ls.c:284)
  ==2782220==    by 0x4D7130: grub_extcmd_dispatcher (extcmd.c:55)
  ==2782220==    by 0x4045A6: execute_command (grub-fstest.c:59)
  ==2782220==    by 0x4045A6: fstest (grub-fstest.c:433)
  ==2782220==    by 0x4045A6: main (grub-fstest.c:772)

This happens when the process of reading the catalog file goes sufficiently
wrong that there's an attempt to read the extent overflow file, which has
not yet been loaded. Keep track of when the extent overflow file is
fully loaded and refuse to use it before then.

The load valgrind doesn't like is btree->nodesize, and that's then used
to allocate a data structure. It looks like there are subsequently a lot
of reads based on that pointer so OOB reads are likely, and indeed crashes
(albeit difficult-to-replicate ones) have been observed in fuzzing.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 58ea11d5b9 fs/hfsplus: Don't fetch a key beyond the end of the node
Otherwise you get a wild pointer, leading to a bunch of invalid reads.
Check it falls inside the given node.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens b5bc456f66 fs/fshelp: Catch impermissibly large block sizes in read helper
A fuzzed HFS+ filesystem had log2blocksize = 22. This gave
log2blocksize + GRUB_DISK_SECTOR_BITS = 31. 1 << 31 = 0x80000000,
which is -1 as an int. This caused some wacky behavior later on in
the function, leading to out-of-bounds writes on the destination buffer.

Catch log2blocksize + GRUB_DISK_SECTOR_BITS >= 31. We could be stricter,
but this is the minimum that will prevent integer size weirdness.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 829329bddb term/gfxterm: Don't set up a font with glyphs that are too big
Catch the case where we have a font so big that it causes the number of
rows or columns to be 0. Currently we continue and allocate a
virtual_screen.text_buffer of size 0. We then try to use that for glpyhs
and things go badly.

On the emu platform, malloc() may give us a valid pointer, in which case
we'll access heap memory which we shouldn't. Alternatively, it may give us
NULL, in which case we'll crash. For other platforms, if I understand
grub_memalign() correctly, we will receive a valid but small allocation
that we will very likely later overrun.

Prevent the creation of a virtual screen that isn't at least 40 cols
by 12 rows. This is arbitrary, but it seems that if your width or height
is half a standard 80x24 terminal, you're probably going to struggle to
read anything anyway.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 8338a8238f video/readers/jpeg: Don't decode data before start of stream
When a start of stream marker is encountered, we call grub_jpeg_decode_sos()
which allocates space for a bitmap.

When a restart marker is encountered, we call grub_jpeg_decode_data() which
then fills in that bitmap.

If we get a restart marker before the start of stream marker, we will
attempt to write to a bitmap_ptr that hasn't been allocated. Catch this
and bail out. This fixes an attempt to write to NULL.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 34b85a6e07 video/readers/jpeg: Catch OOB reads/writes in grub_jpeg_decode_du()
The key line is:

  du[jpeg_zigzag_order[pos]] = val * (int) data->quan_table[qt][pos];

jpeg_zigzag_order is grub_uint8_t[64].

I don't understand JPEG decoders quite well enough to explain what's
going on here. However, I observe sometimes pos=64, which leads to an
OOB read of the jpeg_zigzag_order global then an OOB write to du.
That leads to various unpleasant memory corruption conditions.

Catch where pos >= ARRAY_SIZE(jpeg_zigzag_order) and bail.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens 693989598f video/readers/jpeg: Catch files with unsupported quantization or Huffman tables
Our decoder only supports 2 quantization tables. If a file asks for
a quantization table with index > 1, reject it.

Similarly, our decoder only supports 4 Huffman tables. If a file asks
for a Huffman table with index > 3, reject it.

This fixes some out of bounds reads. It's not clear what degree of control
over subsequent execution could be gained by someone who can carefully
set up the contents of memory before loading an invalid JPEG file.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:18 +01:00
Daniel Axtens f41f0af48a kern/misc: Always set *end in grub_strtoull()
Currently, if there is an error in grub_strtoull(), *end is not set.
This differs from the usual behavior of strtoull(), and also means that
some callers may use an uninitialized value for *end.

Set *end unconditionally.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:17 +01:00
Daniel Axtens 2f533a89a8 commands/menuentry: Fix quoting in setparams_prefix()
Commit 9acdcbf325 (use single quotes in menuentry setparams command)
says that expressing a quoted single quote will require 3 characters. It
actually requires (and always did require!) 4 characters:

  str: a'b => a'\''b
  len:  3  => 6 (2 for the letters + 4 for the quote)

This leads to not allocating enough memory and thus out of bounds writes
that have been observed to cause heap corruption.

Allocate 4 bytes for each single quote.

Commit 22e7dbb2bb (Fix quoting in legacy parser.) does the same
quoting, but it adds 3 as extra overhead on top of the single byte that
the quote already needs. So it's correct.

Fixes: 9acdcbf325 (use single quotes in menuentry setparams command)
Fixes: CVE-2021-20233

Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:17 +01:00
Daniel Axtens 0a05f88e2b script/execute: Don't crash on a "for" loop with no items
The following crashes the parser:

  for x in; do
  0
  done

This is because grub_script_arglist_to_argv() doesn't consider the
possibility that arglist is NULL. Catch that explicitly.

This avoids a NULL pointer dereference.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:17 +01:00
Daniel Axtens 2a330dba93 lib/arg: Block repeated short options that require an argument
Fuzzing found the following crash:

  search -hhhhhhhhhhhhhf

We didn't allocate enough option space for 13 hints because the
allocation code counts the number of discrete arguments (i.e. argc).
However, the shortopt parsing code will happily keep processing
a combination of short options without checking if those short
options require an argument. This means you can easily end writing
past the allocated option space.

This fixes a OOB write which can cause heap corruption.

Fixes: CVE-2021-20225

Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:17 +01:00
Daniel Axtens fe0586347e script/execute: Avoid crash when using "$#" outside a function scope
"$#" represents the number of arguments to a function. It is only
defined in a function scope, where "scope" is non-NULL. Currently,
if we attempt to evaluate "$#" outside a function scope, "scope" will
be NULL and we will crash with a NULL pointer dereference.

Do not attempt to count arguments for "$#" if "scope" is NULL. This
will result in "$#" being interpreted as an empty string if evaluated
outside a function scope.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:17 +01:00
Daniel Axtens 6afbe6063c commands/ls: Require device_name is not NULL before printing
This can be triggered with:
  ls -l (0 0*)
and causes a NULL deref in grub_normal_print_device_info().

I'm not sure if there's any implication with the IEEE 1275 platform.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:17 +01:00
Daniel Axtens 41ae93b2e6 script/execute: Fix NULL dereference in grub_script_execute_cmdline()
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-03-02 15:54:17 +01:00
Daniel Axtens cc316ea337 docs: grub-install --pubkey has been supported for some time
grub-install --pubkey is supported, so we can now document it.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-11-20 14:37:21 +01:00
Daniel Axtens c0c9da5c64 docs: grub-install is no longer a shell script
Since commit cd46aa6cef in 2013, grub-install hasn't been a shell
script. The para doesn't really add that much, especially since it's
the user manual, so just drop it.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-11-20 14:36:50 +01:00
Daniel Axtens 59c8e9fb53 lzma: Fix compilation error under clang 10
Compiling under clang 10 gives:

grub-core/lib/LzmaEnc.c:1362:9: error: misleading indentation; statement is not part of the previous 'if' [-Werror,-Wmisleading-indentation]
        {
        ^
grub-core/lib/LzmaEnc.c:1358:7: note: previous statement is here
      if (repIndex == 0)
      ^
1 error generated.

It's not really that unclear in context: there's a commented-out
if-statement. But tweak the alignment anyway so that clang is happy.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-10-30 21:53:00 +01:00
Daniel Axtens 06fd69a3fd powerpc/mkimage: Fix CHRP note descsz
Currently, an image generated with 'grub-mkimage -n' causes an error when
read with 'readelf -a':

Displaying notes found at file offset 0x000106f0 with length 0x0000002c:
  Owner                Data size        Description
readelf: Warning: note with invalid namesz and/or descsz found at offset 0x0
readelf: Warning:  type: 0x1275, namesize: 0x00000008, descsize: 0x0000002c, alignment: 4

This is because the descsz of the CHRP note is set to
 sizeof (struct grub_ieee1275_note)
which is the size of the entire note, including name and elf header. The
desczs should contain only the contents, not the name and header sizes.

Set the descsz instead to 'sizeof (struct grub_ieee1275_note_desc)'

Resultant readelf output:

Displaying notes found at file offset 0x00010710 with length 0x0000002c:
  Owner                Data size        Description
  PowerPC              0x00000018       Unknown note type: (0x00001275)
   description data: ff ff ff ff 00 c0 00 00 ff ff ff ff ff ff ff ff ff ff ff ff 00 00 40 00

So far as I can tell this issue has existed for as long as the note
generation code has existed, but I guess nothing really checks descsz.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-04-21 22:00:59 +02:00