bochs: Check extent_size header field (CVE-2014-0142)
This fixes two possible division by zero crashes: In bochs_open() and in seek_to_sector(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
parent
e3737b820b
commit
8e53abbc20
|
@ -148,6 +148,14 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags,
|
||||||
s->extent_blocks = 1 + (le32_to_cpu(bochs.extent) - 1) / 512;
|
s->extent_blocks = 1 + (le32_to_cpu(bochs.extent) - 1) / 512;
|
||||||
|
|
||||||
s->extent_size = le32_to_cpu(bochs.extent);
|
s->extent_size = le32_to_cpu(bochs.extent);
|
||||||
|
if (s->extent_size == 0) {
|
||||||
|
error_setg(errp, "Extent size may not be zero");
|
||||||
|
return -EINVAL;
|
||||||
|
} else if (s->extent_size > 0x800000) {
|
||||||
|
error_setg(errp, "Extent size %" PRIu32 " is too large",
|
||||||
|
s->extent_size);
|
||||||
|
return -EINVAL;
|
||||||
|
}
|
||||||
|
|
||||||
if (s->catalog_size < bs->total_sectors / s->extent_size) {
|
if (s->catalog_size < bs->total_sectors / s->extent_size) {
|
||||||
error_setg(errp, "Catalog size is too small for this disk size");
|
error_setg(errp, "Catalog size is too small for this disk size");
|
||||||
|
|
|
@ -43,6 +43,7 @@ _supported_proto generic
|
||||||
_supported_os Linux
|
_supported_os Linux
|
||||||
|
|
||||||
catalog_size_offset=$((0x48))
|
catalog_size_offset=$((0x48))
|
||||||
|
extent_size_offset=$((0x50))
|
||||||
disk_size_offset=$((0x58))
|
disk_size_offset=$((0x58))
|
||||||
|
|
||||||
echo
|
echo
|
||||||
|
@ -68,6 +69,18 @@ _use_sample_img empty.bochs.bz2
|
||||||
poke_file "$TEST_IMG" "$disk_size_offset" "\x00\xc0\x0f\x00\x00\x00\x00\x7f"
|
poke_file "$TEST_IMG" "$disk_size_offset" "\x00\xc0\x0f\x00\x00\x00\x00\x7f"
|
||||||
{ $QEMU_IO -c "read 2T 4k" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
|
{ $QEMU_IO -c "read 2T 4k" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
|
||||||
|
|
||||||
|
echo
|
||||||
|
echo "== Negative extent size =="
|
||||||
|
_use_sample_img empty.bochs.bz2
|
||||||
|
poke_file "$TEST_IMG" "$extent_size_offset" "\xff\xff\xff\xff"
|
||||||
|
{ $QEMU_IO -c "read 768k 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
|
||||||
|
|
||||||
|
echo
|
||||||
|
echo "== Zero extent size =="
|
||||||
|
_use_sample_img empty.bochs.bz2
|
||||||
|
poke_file "$TEST_IMG" "$extent_size_offset" "\x00\x00\x00\x00"
|
||||||
|
{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
|
||||||
|
|
||||||
# success, all done
|
# success, all done
|
||||||
echo "*** done"
|
echo "*** done"
|
||||||
rm -f $seq.full
|
rm -f $seq.full
|
||||||
|
|
|
@ -15,4 +15,12 @@ no file open, try 'help open'
|
||||||
== Too small catalog bitmap for image size ==
|
== Too small catalog bitmap for image size ==
|
||||||
qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
|
qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
|
||||||
no file open, try 'help open'
|
no file open, try 'help open'
|
||||||
|
|
||||||
|
== Negative extent size ==
|
||||||
|
qemu-io: can't open device TEST_DIR/empty.bochs: Extent size 4294967295 is too large
|
||||||
|
no file open, try 'help open'
|
||||||
|
|
||||||
|
== Zero extent size ==
|
||||||
|
qemu-io: can't open device TEST_DIR/empty.bochs: Extent size may not be zero
|
||||||
|
no file open, try 'help open'
|
||||||
*** done
|
*** done
|
||||||
|
|
Loading…
Reference in New Issue