Coverity marks multiple issues in grub-core/fs/zfs/zfs.c as either "Untrusted
value as argument", "Untrusted pointer read", or "Untrusted loop bound". Each
of these issues share a common cause where Coverity finds that data->dnode_buf
gets tainted by dnbuf since it is downcasting from (void *) to (dnode_phys_t *)
and could imply that the data the pointer points to is tainted. However, the
function zio_read(), which reads this data from disk, sanitizes this data by
verifying its checksum. To resolve the issues for Coverity, setting dnbuf to
(dnode_phys_t *) at the start of the function dnode_get() seems to do the trick.
Fixes: CID 314020
Fixes: CID 896330
Fixes: CID 896331
Fixes: CID 896334
Fixes: CID 896336
Fixes: CID 896340
Fixes: CID 897337
Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Improved ad-hoc fuzzing coverage revealed a possible access violation
around line 342 of grub-core/fs/ntfs.c when accessing the attr_cur
pointer due to possibility of moving pointer "next" beyond of the end of
the valid buffer inside next_attribute. Prevent this for cases where
full attribute validation is not performed (such as on attribute lists)
by performing a sanity check on the newly calculated next pointer.
Fixes: 06914b614 (fs/ntfs: Correct attribute vs attribute list validation)
Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The old wiki link is obsolete and no longer updated. Change it to the
current documentation.
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This patch reserves space for the GRUB environment block inside the
Btrfs header. The block is placed at an offset of GRUB_ENV_BTRFS_OFFSET,
256 KiB from the start of the device, and occupies one sector. To
protect the space, overflow guard sectors are placed before and after
the reserved block.
The Btrfs header already defines regions for bootloader use. By adding
this entry, GRUB gains a fixed and safe location to store the environment
block without conflicting with other structures in the header.
Add Btrfs and its reserved area information to the fs_envblk_spec table.
With the groundworks done in previous patches, the function is now
complete and working in grub-editenv.
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The "permissions" field of hfsplus files is only used by Mac OS X. This
causes GRUB to skip reading files created by Mac OS 9, since their
file mode is read as unknown. Instead, assume files with zero mode
are regular files.
From Technote 1150:
The traditional Mac OS implementation of HFS Plus does not use the
permissions field. Files created by traditional Mac OS have the
entire field set to 0.
Signed-off-by: Dave Vasilevsky <dave@vasilevsky.ca>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Avoid attempting to defererence a NULL pointer to call read_symlink() when
the given filesystem does not provide a read_symlink() function. This could
be triggered if the calling filesystem had a file marked as a symlink.
This appears possible for HFS and was observed during fuzzing of NTFS.
Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Correct several infinite loops/hangs found during fuzzing. The issues
fixed here could occur if certain specific malformed NTFS file systems
were presented to GRUB. Currently, GRUB does not allow NTFS file system
access when lockdown mode is enforced, so these should be of minimal
impact.
The changes made in this commit generally correct issues such as attempting
to iterate through a buffer using a length read from the NTFS file system
without confirming the length is larger than 0.
Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Correct several memory access violations found during fuzzing.
The issues fixed here could occur if certain specific malformed NTFS
file systems were presented to GRUB. Currently, GRUB does not allow NTFS
file system access when lockdown mode is enforced, so these should be of
minimal impact.
The changes made in this commit generally correct issues where pointers
into data buffers were being calculated using lengths read from the
NTFS file system without sufficient bounds/sanity checking; or
attempting to access elements of a structure to free them, when the
structure pointer is NULL.
Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Correct ntfs_test test failures around attempting to validate attribute
list entries as attributes. The NTFS code uses common logic in some
places to parse both attributes and attribute_lists which complicates
validation. Attribute lists contain different headers including a
different size of the length field (2 bytes) at offset 4 instead of the
4 byte length field used in attributes at offset 4. There are other
differences as well, but attempting to validate attribute list types
using attribute header validation was causing failure of the NTFS test
suite. This change restores some of the validation logic which may be
shared between attributes and attribute lists to be closer to the
original logic prior to fixes for previous CVEs. A following commit will
address some of the implications of removing this validation logic by
correcting some fuzzer failures (some which are exposed by removing the
validation in some of the cases).
Fixes: 067b6d225 (fs/ntfs: Implement attribute verification)
Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Correct ntfs_test test failures around attempting to validate attribute
run list values. The calculation was incorrect for the "curr" variable.
With previous calculation, some file systems would fail validation
despite being well-formed and valid. This was caused by incrementing
"curr" by min_size which included both the (already accounted for)
min_size as well as the size of the run list. Correct by making a new
variable "run_size" to denote the current run list size to increment
both "curr" and "min_size" separately.
Fixes: 067b6d225 (fs/ntfs: Implement attribute verification)
Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Commit b66c6f918 (fs/zfs: Fix a number of memory leaks in ZFS code)
fixes many of the same leaks detected in bug #63846 except one, which
is fixed here.
Fixes: https://savannah.gnu.org/bugs/?63846
Fixes: b66c6f918 (fs/zfs: Fix a number of memory leaks in ZFS code)
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When large extent counter / NREXT64 support was added to GRUB, it missed
a couple of direct reads of nextents which need to be changed to the new
NREXT64-aware helper as well. Without this, we'll have mis-reads of some
directories with this feature enabled.
The large extent counter fix likely raced on merge with commit 07318ee7e
(fs/xfs: Fix XFS directory extent parsing) which added the new direct
nextents reads just prior, causing this issue.
Fixes: aa7c1322671e (fs/xfs: Add large extent counters incompat feature support)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Anthony Iliopoulos <ailiop@suse.com>
Reviewed-by: Jon DeVree <nuxi@vault24.org>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
A regression was introduced recently as a part of the series of
filesystem related patches to address some CVEs found in GRUB.
This issue may cause either an infinite loop at startup when
accessing certain valid NTFS filesystems, or may cause a crash
due to a NULL pointer dereference on systems where NULL address
is invalid (such as may happen when calling grub-mount from
the operating system level).
Correct this issue by checking that at->attr_cur is within bounds
inside find_attr().
Fixes: https://savannah.gnu.org/bugs/?66855
Fixes: aff263187 (fs/ntfs: Fix out-of-bounds read)
Signed-off-by: B Horn <b@horn.uk>
Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Without this fix the GRUB failed to boot linux with "out of memory" after
trying to run a "search --fs-uuid..." on a system that has 7 ZFS pools
across about 80 drives.
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Commit ef7850c757 (fs/xfs: Fix issues found while fuzzing the XFS
filesystem) introduced multiple boundary checks in grub_xfs_iterate_dir()
but handled the error incorrectly returning error code instead of 0.
Fix it. Also change the error message so that it doesn't match the
message in grub_xfs_read_inode().
Fixes: ef7850c757 (fs/xfs: Fix issues found while fuzzing the XFS filesystem)
Signed-off-by: Egor Ignatov <egori@altlinux.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The Linux port of XFS added a few new features in 2024. The existing
GRUB driver doesn't attempt to read or write any of the new metadata,
so, all three can be added to the incompat allowlist.
On the occasion align XFS_SB_FEAT_INCOMPAT_NREXT64 value.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Previously, the number of extent entries was not properly capped based
on the actual available space. This could lead to insufficient reads for
external extents since the computation was based solely on the inline
extent layout.
In this patch, when processing the extent header we determine whether
the header is stored inline, i.e. at inode->blocks.dir_blocks, or in an
external extent block. We then clamp the number of entries accordingly
(using max_inline_ext for inline extents and max_external_ext for
external extent blocks).
This change ensures that only the valid number of extent entries is
processed preventing out-of-bound reads and potential filesystem
corruption.
Fixes: 7e2f750f0a (fs/ext2: Fix out-of-bounds read for inline extents)
Signed-off-by: Michael Chang <mchang@suse.com>
Tested-by: Christian Hesse <mail@eworm.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Update the overflow error messages to make them consistent
across the GRUB code.
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When using grub_zalloc(), if we are out of memory, this function can fail.
After allocating memory, we should check if grub_zalloc() returns NULL.
If so, we should handle this error.
Fixes: CID 473856
Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When using grub_malloc() or grub_zalloc(), these functions can fail if
we are out of memory. After allocating memory we should check if these
functions returned NULL and handle this error if they did.
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Use grub_calloc() when allocating memory for arrays to ensure proper
overflow checks are in place.
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Replace direct arithmetic operations with macros from include/grub/safemath.h
to prevent potential overflow issues when calculating the memory sizes.
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The direct assignment of the unsigned long long value returned by
read_number() can potentially lead to an overflow on a 32-bit systems.
The fix replaces the direct assignments with calls to grub_cast()
which detects the overflows and safely assigns the values if no
overflow is detected.
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Use grub_calloc() when allocating memory for arrays to ensure proper
overflow checks are in place.
The HFS+ and squash4 security vulnerabilities were reported by
Jonathan Bar Or <jonathanbaror@gmail.com>.
Fixes: CVE-2025-0678
Fixes: CVE-2025-1125
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Replace direct arithmetic operations with macros from include/grub/safemath.h
to prevent potential overflow issues when calculating the memory sizes.
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The idea is to permit the following: btrfs, cpio, exfat, ext, f2fs, fat,
hfsplus, iso9660, squash4, tar, xfs and zfs.
The JFS, ReiserFS, romfs, UDF and UFS security vulnerabilities were
reported by Jonathan Bar Or <jonathanbaror@gmail.com>.
Fixes: CVE-2025-0677
Fixes: CVE-2025-0684
Fixes: CVE-2025-0685
Fixes: CVE-2025-0686
Fixes: CVE-2025-0689
Suggested-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The BFS is not fuzz-clean. Don't allow it to be loaded under lockdown.
This will also disable the AFS.
Fixes: CVE-2024-45778
Fixes: CVE-2024-45779
Reported-by: Nils Langius <nils@langius.de>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The grub_file_open() and grub_file_close() should be the only places
that allow a reference to a filesystem to stay open. So, add grub_dl_t
to grub_fs_t and set this in the GRUB_MOD_INIT() for each filesystem to
avoid issues when filesystems forget to do it themselves or do not track
their own references, e.g. squash4.
The fs_label(), fs_uuid(), fs_mtime() and fs_read() should all ref and
unref in the same function but it is essentially redundant in GRUB
single threaded model.
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
It was previously possible for grub_xfs_mount() to return NULL without
setting grub_errno if the XFS version was invalid. This resulted in it
being possible for grub_dl_unref() to be called twice allowing the XFS
module to be unloaded while there were still references to it.
Fixing this problem in general by ensuring a grub_errno is set if the
fail label is reached.
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The number of records in the root key array read from disk was not being
validated against the size of the root node. This could lead to an
out-of-bounds read.
This patch adds a check to ensure that the number of records in the root
key array does not exceed the expected size of a root node read from
disk. If this check detects an out-of-bounds condition the operation is
aborted to prevent random errors due to metadata corruption.
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
It was possible to read OOB when an attribute had a size that exceeded
the allocated buffer. This resolves that by making sure all attributes
that get read are fully in the allocated space by implementing
a function to validate them.
Defining the offsets in include/grub/ntfs.h but they are only used in
the validation function and not across the rest of the NTFS code.
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Right now to access the next attribute the code reads the length of the
current attribute and adds that to the current pointer. This is error
prone as bounds checking needs to be performed all over the place. So,
implement a helper and ensure its used across find_attr() and read_attr().
This commit does *not* implement full bounds checking. It is just the
preparation work for this to be added into the helper.
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The end of the attribute buffer should be stored alongside the rest of
the attribute struct as right now it is not possible to implement bounds
checking when accessing attributes sequentially.
This is done via:
- updating init_attr() to set at->end and check is is not initially out of bounds,
- implementing checks as init_attr() had its type change in its callers,
- updating the value of at->end when needed.
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When parsing NTFS file records the presence of the 0xFF marker indicates
the end of the attribute list. This value signifies that there are no
more attributes to process.
However, when the end marker is missing due to corrupted metadata the
loop continues to read beyond the attribute list resulting in out-of-bounds
reads and potentially entering an infinite loop.
This patch adds a check to provide a stop condition for the loop ensuring
it stops at the end of the attribute list or at the end of the Master File
Table. This guards against out-of-bounds reads and prevents infinite loops.
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When inline extents are used, i.e. the extent tree depth equals zero,
a maximum of four entries can fit into the inode's data block. If the
extent header states a number of entries greater than four the current
ext2 implementation causes an out-of-bounds read. Fix this issue by
capping the number of extents to four when reading inline extents.
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The getblk() returns a value of type grub_int64_t which is assigned to
iagblk and inoblk, both of type grub_uint64_t, in grub_jfs_read_inode()
via grub_jfs_blkno(). This patch fixes the type mismatch in the
functions. Additionally, the getblk() will return 0 instead of -1 on
failure cases. This change is safe because grub_errno is always set in
getblk() to indicate errors and it is later checked in the callers.
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
An extent's logical offset and address are represented as a 40-bit value
split into two parts: the most significant 8 bits and the least
significant 32 bits. Currently the JFS code uses only the least
significant 32 bits value for offsets and addresses assuming the data
size will never exceed the 32-bit range. This approach ignores the most
significant 8 bits potentially leading to incorrect offsets and
addresses for larger values. The patch fixes it by incorporating the
most significant 8 bits into the calculation to get the full 40-bits
value for offsets and addresses.
https://jfs.sourceforge.net/project/pub/jfslayout.pdf
"off1,off2 is a 40-bit field, containing the logical offset of the first
block in the extent.
...
addr1,addr2 is a 40-bit field, containing the address of the extent."
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Alec Brown <alec.r.brown@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
While fuzz testing JFS with ASAN enabled an OOB read was detected in
grub_jfs_opendir(). The issue occurred due to an invalid directory slot
index in the first entry of the sorted directory slot array in the inode
directory header. The fix ensures the slot index is validated before
accessing it. Given that an internal or a leaf node in a directory B+
tree is a 4 KiB in size and each directory slot is always 32 bytes, the
max number of slots in a node is 128. The validation ensures that the
slot index doesn't exceed this limit.
[1] https://jfs.sourceforge.net/project/pub/jfslayout.pdf
JFS will allocate 4K of disk space for an internal node of the B+ tree.
An internal node looks the same as a leaf node.
- page 10
Fixed number of Directory Slots depending on the size of the node. These are
the slots to be used for storing the directory slot array and the directory
entries or router entries. A directory slot is always 32 bytes.
...
A Directory Slot Array which is a sorted array of indices to the directory
slots that are currently in use.
...
An internal or a leaf node in the directory B+ tree is a 4K page.
- page 25
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Alec Brown <alec.r.brown@oracle.com>
The JFS fuzzing revealed an OOB read in grub_jfs_getent(). The crash
was caused by an invalid leaf nodes count, diro->dirpage->header.count,
which was larger than the maximum number of leaf nodes allowed in an
inode. This fix is to ensure that the leaf nodes count is validated in
grub_jfs_opendir() before calling grub_jfs_getent().
On the occasion replace existing raw numbers with newly defined constant.
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Alec Brown <alec.r.brown@oracle.com>
The ctx->filename can point to either a string literal or a dynamically
allocated string. The ctx->filename_alloc field is used to indicate the
type of allocation.
An issue has been identified where ctx->filename is reassigned to
a string literal in susp_iterate_dir() but ctx->filename_alloc is not
correctly handled. This oversight causes a memory leak and an invalid
free operation later.
The fix involves checking ctx->filename_alloc, freeing the allocated
string if necessary and clearing ctx->filename_alloc for string literals.
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
It was possible for a grub_errno to not be set if mount of an ISO 9660
filesystem failed when set_rockridge() returned 0.
This isn't known to be exploitable as the other filesystems due to
filesystem helper checking the requested file type. Though fixing
as a precaution.
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
It was possible for mount to fail but not set grub_errno. This led to
a possible double decrement of the module reference count if the NULL
page was mapped.
Fixing in general as a similar bug was fixed in commit 61b13c187
(fs/hfsplus: Set grub_errno to prevent NULL pointer access) and there
are likely more variants around.
Fixes: CVE-2024-45783
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
It was previously possible for grub_errno to not be set when
grub_f2fs_mount() failed if nat_bitmap_ptr() returned NULL.
This issue is solved by ensuring a grub_errno is set in the fail case.
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Both namesize and linksize are derived from hd.size, a 12-digit octal
number parsed by read_number(). Later direct arithmetic calculation like
"namesize + 1" and "linksize + 1" may exceed the maximum value of
grub_size_t leading to heap OOB write. This patch fixes the issue by
using grub_add() and checking for an overflow.
Fixes: CVE-2024-45780
Reported-by: Nils Langius <nils@langius.de>
Signed-off-by: Lidong Chen <lidong.chen@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Alec Brown <alec.r.brown@oracle.com>
It was possible to iterate through grub_cpio_find_file() without
allocating name and not setting mode to GRUB_ARCHELP_ATTR_END, which
would cause the uninitialized value for name to be used as an argument
for canonicalize() in grub_archelp_dir().
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
grub_strcpy() was used to copy a symlink name from the filesystem
image to a heap allocated buffer. This led to a OOB write to adjacent
heap allocations. Fix by using grub_strlcpy().
Fixes: CVE-2024-45781
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Otherwise depending on compiler we end up with umoddi3 reference and
failed module dependency resolution.
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
