Patchwork [11/12] bdrv_img_create: Fix segfault

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Submitter Kevin Wolf
Date June 8, 2011, 1:48 p.m.
Message ID <1307540910-12398-12-git-send-email-kwolf@redhat.com>
Download mbox | patch
Permalink /patch/99441/
State New
Headers show

Comments

Kevin Wolf - June 8, 2011, 1:48 p.m.
Block drivers that don't support creating images don't have a size option. Fail
gracefully instead of segfaulting when trying to access the option's value.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

Patch

diff --git a/block.c b/block.c
index 3036a2d..24a25d5 100644
--- a/block.c
+++ b/block.c
@@ -2881,7 +2881,7 @@  int bdrv_img_create(const char *filename, const char *fmt,
                     char *options, uint64_t img_size, int flags)
 {
     QEMUOptionParameter *param = NULL, *create_options = NULL;
-    QEMUOptionParameter *backing_fmt, *backing_file;
+    QEMUOptionParameter *backing_fmt, *backing_file, *size;
     BlockDriverState *bs = NULL;
     BlockDriver *drv, *proto_drv;
     BlockDriver *backing_drv = NULL;
@@ -2964,7 +2964,8 @@  int bdrv_img_create(const char *filename, const char *fmt,
 
     // The size for the image must always be specified, with one exception:
     // If we are using a backing file, we can obtain the size from there
-    if (get_option_parameter(param, BLOCK_OPT_SIZE)->value.n == -1) {
+    size = get_option_parameter(param, BLOCK_OPT_SIZE);
+    if (size && size->value.n == -1) {
         if (backing_file && backing_file->value.s) {
             uint64_t size;
             char buf[32];