diff options
| -rw-r--r-- | block/dmg.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/block/dmg.c b/block/dmg.c index 5c2c2c231d..a78506ad77 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -26,6 +26,7 @@ #include "qemu/bswap.h" #include "qemu/module.h" #include <zlib.h> +#include <glib.h> enum { /* Limit chunk sizes to prevent unreasonable amounts of memory being used @@ -343,12 +344,67 @@ fail: return ret; } +static int dmg_read_plist_xml(BlockDriverState *bs, DmgHeaderState *ds, + uint64_t info_begin, uint64_t info_length) +{ + BDRVDMGState *s = bs->opaque; + int ret; + uint8_t *buffer = NULL; + char *data_begin, *data_end; + + /* Have at least some length to avoid NULL for g_malloc. Attempt to set a + * safe upper cap on the data length. A test sample had a XML length of + * about 1 MiB. */ + if (info_length == 0 || info_length > 16 * 1024 * 1024) { + ret = -EINVAL; + goto fail; + } + + buffer = g_malloc(info_length + 1); + buffer[info_length] = '\0'; + ret = bdrv_pread(bs->file, info_begin, buffer, info_length); + if (ret != info_length) { + ret = -EINVAL; + goto fail; + } + + /* look for <data>...</data>. The data is 284 (0x11c) bytes after base64 + * decode. The actual data element has 431 (0x1af) bytes which includes tabs + * and line feeds. */ + data_end = (char *)buffer; + while ((data_begin = strstr(data_end, "<data>")) != NULL) { + guchar *mish; + gsize out_len = 0; + + data_begin += 6; + data_end = strstr(data_begin, "</data>"); + /* malformed XML? */ + if (data_end == NULL) { + ret = -EINVAL; + goto fail; + } + *data_end++ = '\0'; + mish = g_base64_decode(data_begin, &out_len); + ret = dmg_read_mish_block(s, ds, mish, (uint32_t)out_len); + g_free(mish); + if (ret < 0) { + goto fail; + } + } + ret = 0; + +fail: + g_free(buffer); + return ret; +} + static int dmg_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVDMGState *s = bs->opaque; DmgHeaderState ds; uint64_t rsrc_fork_offset, rsrc_fork_length; + uint64_t plist_xml_offset, plist_xml_length; int64_t offset; int ret; @@ -382,12 +438,31 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, ret = -EINVAL; goto fail; } + /* offset of property list (XMLOffset) */ + ret = read_uint64(bs, offset + 0xd8, &plist_xml_offset); + if (ret < 0) { + goto fail; + } + ret = read_uint64(bs, offset + 0xe0, &plist_xml_length); + if (ret < 0) { + goto fail; + } + if (plist_xml_offset >= offset || + plist_xml_length > offset - plist_xml_offset) { + ret = -EINVAL; + goto fail; + } if (rsrc_fork_length != 0) { ret = dmg_read_resource_fork(bs, &ds, rsrc_fork_offset, rsrc_fork_length); if (ret < 0) { goto fail; } + } else if (plist_xml_length != 0) { + ret = dmg_read_plist_xml(bs, &ds, plist_xml_offset, plist_xml_length); + if (ret < 0) { + goto fail; + } } else { ret = -EINVAL; goto fail; |