From 64ca6aee4f06a3af869e5e09f0afeb6721966875 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 22 Feb 2012 12:37:13 +0100 Subject: qcow2: Reject too large header extensions Image files that make qemu-img info read several gigabytes into the unknown header extensions list are bad. Just fail opening the image if an extension claims to be larger than the header extension area. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi --- block/qcow2.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/block/qcow2.c b/block/qcow2.c index f68f0e1..eb5ea48 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -108,6 +108,11 @@ 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) { + error_report("Header extension too large"); + return -EINVAL; + } + switch (ext.magic) { case QCOW2_EXT_MAGIC_END: return 0; -- cgit v1.1