From f51851ea928882bd3d49cbb6d953723294239d8a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 26 Oct 2011 12:25:52 +0200 Subject: [PATCH] vmdk: Fix possible segfaults MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Data we read from the disk isn't necessarily null terminated and may not contain the string we're looking for. The code needs to be a bit more careful here. Signed-off-by: Kevin Wolf (cherry picked from commit 93897b9fd43548e9c15cf8bece2d9e5174b01fc7) Signed-off-by: Bruce Rogers Signed-off-by: Andreas Färber --- block/vmdk.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/block/vmdk.c b/block/vmdk.c index 8284747..f4fce08 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -196,6 +196,7 @@ static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent) cid_str_size = sizeof("CID"); } + desc[DESC_SIZE - 1] = '\0'; p_name = strstr(desc, cid_str); if (p_name != NULL) { p_name += cid_str_size; @@ -212,13 +213,17 @@ static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid) BDRVVmdkState *s = bs->opaque; int ret; - memset(desc, 0, sizeof(desc)); ret = bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE); if (ret < 0) { return ret; } + desc[DESC_SIZE - 1] = '\0'; tmp_str = strstr(desc, "parentCID"); + if (tmp_str == NULL) { + return -EINVAL; + } + pstrcpy(tmp_desc, sizeof(tmp_desc), tmp_str); p_name = strstr(desc, "CID"); if (p_name != NULL) { -- 1.7.11.2