From e729fa6afed3aa917287b63034244f548b79ec60 Mon Sep 17 00:00:00 2001 From: Jeff Cody Date: Tue, 27 Jan 2015 08:33:55 -0500 Subject: [PATCH] block: fix off-by-one error in qcow and qcow2 This fixes an off-by-one error introduced in 9a29e18. Both qcow and qcow2 need to make sure to leave room for string terminator '\0' for the backing file, so the max length of the non-terminated string is either 1023 or PATH_MAX - 1. Reported-by: Kevin Wolf Signed-off-by: Jeff Cody Signed-off-by: Kevin Wolf --- block/qcow.c | 2 +- block/qcow2.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/block/qcow.c b/block/qcow.c index ccbe9e0d2c..055896910e 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -215,7 +215,7 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, /* read the backing file name */ if (header.backing_file_offset != 0) { len = header.backing_file_size; - if (len > 1023 || len > sizeof(bs->backing_file)) { + if (len > 1023 || len >= sizeof(bs->backing_file)) { error_setg(errp, "Backing file name too long"); ret = -EINVAL; goto fail; diff --git a/block/qcow2.c b/block/qcow2.c index dbaf016bc7..7e614d76a4 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -869,7 +869,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, if (header.backing_file_offset != 0) { len = header.backing_file_size; if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || - len > sizeof(bs->backing_file)) { + len >= sizeof(bs->backing_file)) { error_setg(errp, "Backing file name too long"); ret = -EINVAL; goto fail;