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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
"$#" represents the number of arguments to a function. It is only
defined in a function scope, where "scope" is non-NULL. Currently,
if we attempt to evaluate "$#" 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>
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>
It is possible for the ftell() function to return a negative value,
although it is fairly unlikely here, we should be checking for
a negative value before we assign it to an unsigned value.
Fixes: CID 73744
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The return value of ftell() may be negative (-1) on error. While it is
probably unlikely to occur, we should not blindly cast to an unsigned
value without first testing that it is not negative.
Fixes: CID 73856
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Two grub_device_open() calls does not have associated NULL checks
for returned values. Fix that and appease the Coverity.
Fixes: CID 314583
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
The code here is finished with the memory stored in name, but it only
frees it if there curvalue is valid, while it could actually free it
regardless.
The fix is a simple relocation of the grub_free() to before the test
of curvalue.
Fixes: CID 96646
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
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>
The test of value for NULL before calling grub_strdup() is not required,
since the if condition prior to this has already tested for value being
NULL and cannot reach this code if it is.
Fixes: CID 73659
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
While it may never happen, and potentially could be caught at the end of
the function, it is worth checking up front for a bad reference to the
next marker just in case of a maliciously crafted file being provided.
Fixes: CID 73694
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
It is minimal possibility that the values being used here will overflow.
So, change the code to use the safemath function grub_mul() to ensure
that doesn't happen.
Fixes: CID 73761
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The calculation of the unsigned 64-bit value is being generated by
multiplying 2, signed or unsigned, 32-bit integers which may overflow
before promotion to unsigned 64-bit. Fix all of them.
Fixes: CID 73703, CID 73767, CID 73833
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The multiplication of 2 unsigned 32-bit integers may overflow before
promotion to unsigned 64-bit. We should ensure that the multiplication
is done with overflow detection. Additionally, use grub_sub() for
subtraction.
Fixes: CID 73640, CID 73697, CID 73702, CID 73823
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Marco A Benatto <mbenatto@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The return value of grub_video_gop_fill_mode_info() is never able to be
anything other than GRUB_ERR_NONE. So, rather than continue to return
a value and checking it each time, it is more correct to redefine the
function to not return anything and remove checks of its return value
altogether.
Fixes: CID 96701
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Every other return statement in this code is calling grub_device_close()
to clean up dev before returning. This one should do that too.
Fixes: CID 292443
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
check_list() uses grub_file_getline(), which allocates a buffer.
If the hash list file contains invalid lines, the function leaks
this buffer when it returns an error.
Fixes: CID 176635
Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
It is possible for the code to reach the end of the function without
freeing the memory allocated to argv and argc still to be 0.
We should always call grub_free(argv). The grub_free() will handle
a NULL argument correctly if it reaches that code without the memory
being allocated.
Fixes: CID 96672
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
In syslinux_parse_real() the 2 points where return is being called
didn't release the memory stored in buf which is no longer required.
Fixes: CID 176634
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The code in gcry_mpi_scan() assumes that buffer is not NULL, but there
is no explicit check for that, so we add one.
Fixes: CID 73757
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The array of unsigned char gets promoted to a signed 32-bit int before
it is finally promoted to a size_t. There is the possibility that this
may result in the signed-bit being set for the intermediate signed
32-bit int. We should ensure that the promotion is to the correct type
before we bitwise-OR the values.
Fixes: CID 96697
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The node structure reference is being allocated but not freed if it
reaches the end of the function. If any of the hooks had returned
a non-zero value, then node would have been copied in to the context
reference, but otherwise node is not stored and should be freed.
Similarly, the call to grub_affs_create_node() replaces the allocated
memory in node with a newly allocated structure, leaking the existing
memory pointed by node.
Finally, when dir->parent is set, then we again replace node with newly
allocated memory, which seems unnecessary when we copy in the values
from dir->parent immediately after.
Fixes: CID 73759
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
While arguably the check for grub_errno is correct, we should really be
checking the return value from the function since it is always possible
that grub_errno was set elsewhere, making this code behave incorrectly.
Fixes: CID 73668
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
In all cases the problem is that the value being acted upon by
a left-shift is a 32-bit number which is then being used in the
context of a 64-bit number.
To avoid overflow we ensure that the number being shifted is 64-bit
before the shift is done.
Fixes: CID 73684, CID 73695, CID 73764
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
There are several exit points in dnode_get_path() that are causing possible
memory leaks.
In the while(1) the correct exit mechanism should not be to do a direct return,
but to instead break out of the loop, setting err first if it is not already set.
The reason behind this is that the dnode_path is a linked list, and while doing
through this loop, it is being allocated and built up - the only way to
correctly unravel it is to traverse it, which is what is being done at the end
of the function outside of the loop.
Several of the existing exit points correctly did a break, but not all so this
change makes that more consistent and should resolve the leaking of memory as
found by Coverity.
Fixes: CID 73741
Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo@canonical.com>
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
While it is possible for the return value from zfs_log2() to be zero
(0), it is quite unlikely, given that the previous assignment to blksz
is shifted up by SPA_MINBLOCKSHIFT (9) before 9 is subtracted at the
assignment to epbs.
But, while unlikely during a normal operation, it may be that a carefully
crafted ZFS filesystem could result in a zero (0) value to the
dn_datalbkszsec field, which means that the shift left does nothing
and assigns zero (0) to blksz, resulting in a negative epbs value.
Fixes: CID 73608
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
HFS+ documentation suggests that the maximum filename and volume name is
255 Unicode characters in length.
So, when converting from big-endian to little-endian, we should ensure
that the name of the volume has a length that is between 0 and 255,
inclusive.
Fixes: CID 73641
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The encrypt and decrypt functions expect a grub_size_t. So, we need to
ensure that the constant bit shift is using grub_size_t rather than
unsigned int when it is performing the shift.
Fixes: CID 307788
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The problem here is that the memory allocated to the variable lv is not
yet inserted into the list that is being processed at the label fail2.
As we can already see at line 342, which correctly frees lv before going
to fail2, we should also be doing that at these earlier jumps to fail2.
Fixes: CID 73824
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
