diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2014-03-26 13:05:34 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-04-01 13:59:47 +0200 |
| commit | 8e53abbc20d08ae3ec30c2054e1161314ad9501d (patch) | |
| tree | bddf225073fc61d129d292b9300e40d9526037fa | |
| parent | e3737b820b45e54b059656dc3f914f895ac7a88b (diff) | |
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>
| -rw-r--r-- | block/bochs.c | 8 | ||||
| -rwxr-xr-x | tests/qemu-iotests/078 | 13 | ||||
| -rw-r--r-- | tests/qemu-iotests/078.out | 8 |
3 files changed, 29 insertions, 0 deletions
diff --git a/block/bochs.c b/block/bochs.c index 0ffa9c1ba7..a922782c1d 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -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_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) { error_setg(errp, "Catalog size is too small for this disk size"); diff --git a/tests/qemu-iotests/078 b/tests/qemu-iotests/078 index 902ef0f036..872e734cab 100755 --- a/tests/qemu-iotests/078 +++ b/tests/qemu-iotests/078 @@ -43,6 +43,7 @@ _supported_proto generic _supported_os Linux catalog_size_offset=$((0x48)) +extent_size_offset=$((0x50)) disk_size_offset=$((0x58)) echo @@ -68,6 +69,18 @@ _use_sample_img empty.bochs.bz2 poke_file "$TEST_IMG" "$disk_size_offset" "\x00\xc0\x0f\x00\x00\x00\x00\x7f" { $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 echo "*** done" rm -f $seq.full diff --git a/tests/qemu-iotests/078.out b/tests/qemu-iotests/078.out index 7254693b08..ea95ffdbb8 100644 --- a/tests/qemu-iotests/078.out +++ b/tests/qemu-iotests/078.out @@ -15,4 +15,12 @@ no file open, try 'help open' == 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 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 |