From ac1f8bc6b596935dd657fa582aaca3f08c1414fb Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 26 Mar 2014 13:05:34 +0100 Subject: [PATCH] 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 Reviewed-by: Stefan Hajnoczi Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi (cherry picked from commit 8e53abbc20d08ae3ec30c2054e1161314ad9501d) Conflicts: tests/qemu-iotests/078 tests/qemu-iotests/078.out --- block/bochs.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block/bochs.c b/block/bochs.c index 4393ecc..10fbd39 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -146,6 +146,14 @@ 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) { + fprintf(stderr, "Extent size may not be zero"); + return -EINVAL; + } else if (s->extent_size > 0x800000) { + fprintf(stderr, "Extent size %" PRIu32 " is too large", + s->extent_size); + return -EINVAL; + } if (s->catalog_size < bs->total_sectors / s->extent_size) { fprintf(stderr, "Catalog size is too small for this disk size");