From 9a29e18f7dfd5a0e80d1c60fc856ebba18ddb738 Mon Sep 17 00:00:00 2001 From: Jeff Cody Date: Thu, 22 Jan 2015 08:03:30 -0500 Subject: [PATCH] block: update string sizes for filename,backing_file,exact_filename The string field entries 'filename', 'backing_file', and 'exact_filename' in the BlockDriverState struct are defined as 1024 bytes. However, many places that use these values accept a maximum of PATH_MAX bytes, so we have a mixture of 1024 byte and PATH_MAX byte allocations. This patch makes the BlockDriverStruct field string sizes match usage. This patch also does a few fixes related to the size that needs to happen now: * the block qapi driver is updated to use PATH_MAX bytes * the qcow and qcow2 drivers have an additional safety check * the block vvfat driver is updated to use PATH_MAX bytes for the size of backing_file, for systems where PATH_MAX is < 1024 bytes. * qemu-img uses PATH_MAX rather than 1024. These instances were not changed to be dynamically allocated, however, as the extra temporary 3K in stack usage for qemu-img does not seem worrisome. Reviewed-by: Stefan Hajnoczi Reviewed-by: John Snow Signed-off-by: Jeff Cody Signed-off-by: Kevin Wolf --- block/qapi.c | 4 ++-- block/qcow.c | 2 +- block/qcow2.c | 3 ++- block/vvfat.c | 4 ++-- include/block/block_int.h | 8 ++++---- qemu-img.c | 4 ++-- 6 files changed, 13 insertions(+), 12 deletions(-) diff --git a/block/qapi.c b/block/qapi.c index dec9f60d10..75c388e90b 100644 --- a/block/qapi.c +++ b/block/qapi.c @@ -210,10 +210,10 @@ void bdrv_query_image_info(BlockDriverState *bs, backing_filename = bs->backing_file; if (backing_filename[0] != '\0') { - char *backing_filename2 = g_malloc0(1024); + char *backing_filename2 = g_malloc0(PATH_MAX); info->backing_filename = g_strdup(backing_filename); info->has_backing_filename = true; - bdrv_get_full_backing_filename(bs, backing_filename2, 1024, &err); + bdrv_get_full_backing_filename(bs, backing_filename2, PATH_MAX, &err); if (err) { error_propagate(errp, err); qapi_free_ImageInfo(info); diff --git a/block/qcow.c b/block/qcow.c index ece22697a6..ccbe9e0d2c 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) { + 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 e4e690a42b..dbaf016bc7 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -868,7 +868,8 @@ static int qcow2_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 > MIN(1023, s->cluster_size - header.backing_file_offset)) { + if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || + len > sizeof(bs->backing_file)) { error_setg(errp, "Backing file name too long"); ret = -EINVAL; goto fail; diff --git a/block/vvfat.c b/block/vvfat.c index e34a789699..a1a44f0ef5 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -2909,8 +2909,8 @@ static int enable_write_target(BDRVVVFATState *s, Error **errp) array_init(&(s->commits), sizeof(commit_t)); - s->qcow_filename = g_malloc(1024); - ret = get_tmp_filename(s->qcow_filename, 1024); + s->qcow_filename = g_malloc(PATH_MAX); + ret = get_tmp_filename(s->qcow_filename, PATH_MAX); if (ret < 0) { error_setg_errno(errp, -ret, "can't create temporary file"); goto err; diff --git a/include/block/block_int.h b/include/block/block_int.h index 06a21dd13d..e264be97b2 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -339,13 +339,13 @@ struct BlockDriverState { * regarding this BDS's context */ QLIST_HEAD(, BdrvAioNotifier) aio_notifiers; - char filename[1024]; - char backing_file[1024]; /* if non zero, the image is a diff of - this file image */ + char filename[PATH_MAX]; + char backing_file[PATH_MAX]; /* if non zero, the image is a diff of + this file image */ char backing_format[16]; /* if non-zero and backing_file exists */ QDict *full_open_options; - char exact_filename[1024]; + char exact_filename[PATH_MAX]; BlockDriverState *backing_hd; BlockDriverState *file; diff --git a/qemu-img.c b/qemu-img.c index 7876258fa9..4e9a7f5741 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -2556,7 +2556,7 @@ static int img_rebase(int argc, char **argv) /* For safe rebasing we need to compare old and new backing file */ if (!unsafe) { - char backing_name[1024]; + char backing_name[PATH_MAX]; blk_old_backing = blk_new_with_bs("old_backing", &error_abort); bs_old_backing = blk_bs(blk_old_backing); @@ -2614,7 +2614,7 @@ static int img_rebase(int argc, char **argv) } old_backing_num_sectors = bdrv_nb_sectors(bs_old_backing); if (old_backing_num_sectors < 0) { - char backing_name[1024]; + char backing_name[PATH_MAX]; bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name)); error_report("Could not get size of '%s': %s",