When a terminator is reached the base for offsets and sectors is stored.
The following records that are processed will use this base value.

If the first record we encounter is a terminator, then calculating the
base values would result in out-of-bounds array accesses.  Don't do
that.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Clean up the mix of tabs and spaces, as well as the coding style
violations in block/dmg.c.  There are no semantic changes since this
patch simply reformats the code.

This patch is necessary before we can make meaningful changes to this
file, due to the inconsistent formatting and confusing indentation.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The size in bytes is assigned to an int later, so check that instead of
the number of entries.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

In order to avoid integer overflows.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

If the size becomes larger than what qcow2_open() would accept, fail the
growing operation.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This ensures that the checks catch all invalid cluster indexes
instead of returning the refcount of a wrong cluster.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

free_cluster_index is only correct if update_refcount() was called from
an allocation function, and even there it's brittle because it's used to
protect unfinished allocations which still have a refcount of 0 - if it
moves in the wrong place, the unfinished allocation can be corrupted.

So not using it any more seems to be a good idea. Instead, use the
first requested cluster to do the calculations. Return -EAGAIN if
unfinished allocations could become invalid and let the caller restart
its search for some free clusters.

The context of creating a snapsnot is one situation where
update_refcount() is called outside of a cluster allocation. For this
case, the change fixes a buffer overflow if a cluster is referenced in
an L2 table that cannot be represented by an existing refcount block.
(new_table[refcount_table_index] was out of bounds)

[Bump the qemu-iotests 026 refblock_alloc.write leak count from 10 to
11.
--Stefan]
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

len could become negative and would pass the check then. Nothing bad
happened because bdrv_pread() happens to return an error for negative
length values, but make variables for sizes unsigned anyway.

This patch also changes the behaviour to error out on invalid lengths
instead of silently truncating it to 1023.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This avoids an unbounded allocation.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This avoid unbounded memory allocation and fixes a potential buffer
overflow on 32 bit hosts.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The end of the refcount table must not exceed INT64_MAX so that integer
overflows are avoided.

Also check for misaligned refcount table. Such images are invalid and
probably the result of data corruption. Error out to avoid further
corruption.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Limit the in-memory reference count table size to 8 MB, it's enough in
practice. This fixes an unbounded allocation as well as a buffer
overflow in qcow2_refcount_init().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Header, header extension and the backing file name must all be stored in
the first cluster. Setting the backing file to a much higher value
allowed header extensions to become much bigger than we want them to be
(unbounded allocation).
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This fixes an unbounded allocation for s->unknown_header_fields.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

curl_read_cb is callback function for libcurl when data arrives. The
data size passed in here is not guaranteed to be within the range of
request we submitted, so we may overflow the guest IO buffer. Check the
real size we have before memcpy to buffer to avoid overflow.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Other variables (e.g. sectors_per_block) are calculated using these
variables, and if not range-checked illegal values could be obtained
causing infinite loops and other potential issues when calculating
BAT entries.

The 1.00 VHDX spec requires BlockSize to be min 1MB, max 256MB.
LogicalSectorSize is required to be either 512 or 4096 bytes.
Reported-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The maximum blocks_in_image is 0xffffffff / 4, which also limits the
maximum disk_size for a VDI image to 1024TB.  Note that this is the maximum
size that QEMU will currently support with this driver, not necessarily the
maximum size allowed by the image format.

This also fixes an incorrect error message, a bug introduced by commit
5b7aa9b5 (Reported by Stefan Weil)
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This fixes some cases of division by zero crashes.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This adds checks to make sure that max_table_entries and block_size
are in sane ranges.  Memory is allocated based on max_table_entries,
and block_size is used to calculate indices into that allocated
memory, so if these values are incorrect that can lead to potential
unbounded memory allocation, or invalid memory accesses.

Also, the allocation of the pagetable is changed from g_malloc0()
to qemu_blockalign().
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

32 bit truncation could let us access the wrong offset in the image.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This fixes two possible division by zero crashes: In bochs_open() and in
seek_to_sector().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

It should neither become negative nor allow unbounded memory
allocations. This fixes aborts in g_malloc() and an s->catalog_bitmap
buffer overflow on big endian hosts.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Gets us rid of integer overflows resulting in negative sizes which
aren't correctly checked.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This is an on-disk structure, so offsets must be accurate.

Before this patch, sizeof(bochs) != sizeof(header_v1), which makes the
memcpy() between both invalid. We're lucky enough that the destination
buffer happened to be the larger one, and the memcpy size to be taken
from the smaller one, so we didn't get a buffer overflow in practice.

This patch unifies the both structures, eliminating the need to do a
memcpy in the first place. The common fields are extracted to the top
level of the struct and the actually differing part gets a union of the
two versions.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

cloop stores the number of compressed blocks in the n_blocks header
field.  The file actually contains n_blocks + 1 offsets, where the extra
offset is the end-of-file offset.

The following line in cloop_read_block() results in an out-of-bounds
offsets[] access:

    uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num];

This patch allocates and loads the extra offset so that
cloop_read_block() works correctly when the last block is accessed.

Notice that we must free s->offsets[] unconditionally now since there is
always an end-of-file offset.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The offsets[] array allows efficient seeking and tells us the maximum
compressed data size.  If the offsets are bogus the maximum compressed
data size will be unrealistic.

This could cause g_malloc() to abort and bogus offsets mean the image is
broken anyway.  Therefore we should refuse such images.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Limit offsets_size to 512 MB so that:

1. g_malloc() does not abort due to an unreasonable size argument.

2. offsets_size does not overflow the bdrv_pread() int size argument.

This limit imposes a maximum image size of 16 TB at 256 KB block size.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The following integer overflow in offsets_size can lead to out-of-bounds
memory stores when n_blocks has a huge value:

    uint32_t n_blocks, offsets_size;
    [...]
    ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4);
    [...]
    s->n_blocks = be32_to_cpu(s->n_blocks);

    /* read offsets */
    offsets_size = s->n_blocks * sizeof(uint64_t);
    s->offsets = g_malloc(offsets_size);

    [...]

    for(i=0;i<s->n_blocks;i++) {
        s->offsets[i] = be64_to_cpu(s->offsets[i]);

offsets_size can be smaller than n_blocks due to integer overflow.
Therefore s->offsets[] is too small when the for loop byteswaps offsets.

This patch refuses to open files if offsets_size would overflow.

Note that changing the type of offsets_size is not a fix since 32-bit
hosts still only have 32-bit size_t.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Avoid unbounded s->uncompressed_block memory allocation by checking that
the block_size header field has a reasonable value.  Also enforce the
assumption that the value is a non-zero multiple of 512.

These constraints conform to cloop 2.639's code so we accept existing
image files.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Add a cloop format-specific test case.  Later patches add tests for
input validation to the script.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Add the cloop block driver to qemu-iotests.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Regressed in commit 7ad9be64, v1.5.0.
Reported-by: NKiyokazu SUTO <suto@ks-and-ks.ne.jp>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NPrasad Joshi <prasadjoshi.linux@gmail.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The -fstack-protector flag family is useful for ensuring safety and for
debugging, but has a performance impact. Here are some boot time comparisons of
the various versions of -fstack-protector using qemu-system-arm on an x86_64
host:

    # -fstack-protector-all
    Startup finished in 1.810s (kernel) + 12.331s (initrd) + 49.016s (userspace) = 1min 3.159s
    Startup finished in 1.801s (kernel) + 12.287s (initrd) + 47.925s (userspace) = 1min 2.013s
    Startup finished in 1.812s (kernel) + 12.302s (initrd) + 47.995s (userspace) = 1min 2.111s

    # -fstack-protector-strong
    Startup finished in 1.744s (kernel) + 11.223s (initrd) + 44.688s (userspace) = 57.657s
    Startup finished in 1.721s (kernel) + 11.222s (initrd) + 44.194s (userspace) = 57.138s
    Startup finished in 1.693s (kernel) + 11.250s (initrd) + 44.426s (userspace) = 57.370s

    # -fstack-protector
    Startup finished in 1.705s (kernel) + 11.409s (initrd) + 43.563s (userspace) = 56.677s
    Startup finished in 1.877s (kernel) + 11.137s (initrd) + 43.719s (userspace) = 56.734s
    Startup finished in 1.708s (kernel) + 11.141s (initrd) + 43.628s (userspace) = 56.478s

    # no stack protector
    Startup finished in 1.743s (kernel) + 11.190s (initrd) + 43.709s (userspace) = 56.643s
    Startup finished in 1.763s (kernel) + 11.216s (initrd) + 43.767s (userspace) = 56.747s
    Startup finished in 1.711s (kernel) + 11.283s (initrd) + 43.878s (userspace) = 56.873s

This patch introduces a configure option to disable the stack protector
entirely, and conditional stack protector flag selection (in order,
based on availability): -fstack-protector-strong, -fstack-protector-all,
no stack protector.
Signed-off-by: NSteven Noonan <snoonan@amazon.com>
Cc: Anthony Liguori <aliguori@amazon.com>
Reviewed-by: NStefan Weil <sw@weilnetz.de>
[Prefer -fstack-protector-all to -fstack-protector, suggested by
 Laurent Desnogues. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

irq_state is cleared before calling pci_device_deassert_intx, but the
latter misbehaves if the former isn't accurate. In this case, any raised
IRQs are not cleared, which hits an assertion in pcibus_reset:

qemu-system-x86_64: hw/pci/pci.c:250: pcibus_reset: Assertion
`bus->irq_count[i] == 0' failed.

pci_device_deassert_intx should clear irq_state anyways, so add
an assert.

This fixes migration with usb2 + usb-tablet.
Signed-off-by: NCole Robinson <crobinso@redhat.com>
Message-id: 7da1ad94ce027183b4049c2de370cb191b0073c1.1396290569.git.crobinso@redhat.com
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

QOM CPUState refactorings / X86CPU

* X86CPU IA32e 1GB paging support
* Performance quickfix for CPU() cast macro

# gpg: Signature made Mon 31 Mar 2014 18:33:27 BST using RSA key ID 3E7E013F
# gpg: Good signature from "Andreas Färber <afaerber@suse.de>"
# gpg:                 aka "Andreas Färber <afaerber@suse.com>"

* remotes/afaerber/tags/qom-cpu-for-2.0:
  cpu: Avoid QOM casts for CPU()
  target-i386: x86_cpu_get_phys_page_debug(): support 1GB page translation
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

CPU address spaces touching load and store helpers as well as the
movement of (almost) all fields from CPU_COMMON to CPUState have led to
a noticeable increase of CPU() usage in "hot" paths for both TCG and KVM.

While CPU()'s OBJECT_CHECK() might help detect development errors, i.e.
in form of crashes due to QOM vs. non-QOM mismatches rather than QOM
type mismatches, it is not really needed at runtime since mostly used in
CPU-specific paths, coming from a target-specific CPU subtype. If that
pointer is damaged, other errors are highly likely to occur elsewhere
anyway.

Keep the CPU() macro for a consistent developer experience and for
flexibility to exchange its implementation, but turn it into a pure,
unchecked C cast for now.

Compare commit 6e42be7c.
Reported-by: NLaurent Desnogues <laurent.desnogues@gmail.com>
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>