diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2014-11-25 18:12:40 +0100 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2015-01-14 17:08:42 -0600 |
| commit | b495764ae801daeb4ec690b628301f75838352a1 (patch) | |
| tree | bd4c6111e1b8b379519df229eb0a106dcaf25d7a | |
| parent | 21640bf6e08e4d69bab1bd1ea0bed562d1fc726c (diff) | |
| download | qemu-b495764ae801daeb4ec690b628301f75838352a1.tar.gz | |
qcow2: Fix header extension size check
After reading the extension header, offset is incremented, but not
checked against end_offset any more. This way an integer overflow could
happen when checking whether the extension end is within the allowed
range, effectively disabling the check.
This patch adds the missing check and a test case for it.
Cc: qemu-stable@nongnu.org
Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1416935562-7760-2-git-send-email-kwolf@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 2ebafc854d109ff09b66fb4dd62c2c53fc29754a)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
| -rw-r--r-- | block/qcow2.c | 2 | ||||
| -rwxr-xr-x | tests/qemu-iotests/080 | 2 | ||||
| -rw-r--r-- | tests/qemu-iotests/080.out | 2 |
3 files changed, 5 insertions, 1 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index d53f181829..ea6d3f27e1 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -114,7 +114,7 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, #ifdef DEBUG_EXT printf("ext.magic = 0x%x\n", ext.magic); #endif - if (ext.len > end_offset - offset) { + if (offset > end_offset || ext.len > end_offset - offset) { error_setg(errp, "Header extension too large"); return -EINVAL; } diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080 index 6b3a3e77a5..b9f9630db8 100755 --- a/tests/qemu-iotests/080 +++ b/tests/qemu-iotests/080 @@ -78,6 +78,8 @@ poke_file "$TEST_IMG" "$offset_backing_file_offset" "\xff\xff\xff\xff\xff\xff\xf poke_file "$TEST_IMG" "$offset_ext_magic" "\x12\x34\x56\x78" poke_file "$TEST_IMG" "$offset_ext_size" "\x7f\xff\xff\xff" { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +poke_file "$TEST_IMG" "$offset_backing_file_offset" "\x00\x00\x00\x00\x00\x00\x00\x$(printf %x $offset_ext_size)" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir poke_file "$TEST_IMG" "$offset_backing_file_offset" "\x00\x00\x00\x00\x00\x00\x00\x00" { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out index f7a943c7a4..33d1f71232 100644 --- a/tests/qemu-iotests/080.out +++ b/tests/qemu-iotests/080.out @@ -13,6 +13,8 @@ qemu-io: can't open device TEST_DIR/t.qcow2: Invalid backing file offset no file open, try 'help open' qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large +no file open, try 'help open' == Huge refcount table size == Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 |