Patchwork [PULL,11/30] block: Don't copy backing file name on error

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Submitter Kevin Wolf
Date Oct. 31, 2013, 3:48 p.m.
Message ID <1383234524-372-12-git-send-email-kwolf@redhat.com>
Download mbox | patch
Permalink /patch/287532/
State New
Headers show

Comments

Kevin Wolf - Oct. 31, 2013, 3:48 p.m.
From: Max Reitz <mreitz@redhat.com>

bdrv_open_backing_file() tries to copy the backing file name using
pstrcpy directly after calling bdrv_open() to open the backing file
without checking whether that was actually successful. If it was not,
ps->backing_hd->file will probably be NULL and qemu will crash.

Fix this by moving pstrcpy after checking whether bdrv_open() succeeded.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Amos Kong <kongjianjun@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Patch

diff --git a/block.c b/block.c
index fd05a80..366999b 100644
--- a/block.c
+++ b/block.c
@@ -1004,8 +1004,6 @@  int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
     ret = bdrv_open(bs->backing_hd,
                     *backing_filename ? backing_filename : NULL, options,
                     back_flags, back_drv, &local_err);
-    pstrcpy(bs->backing_file, sizeof(bs->backing_file),
-            bs->backing_hd->file->filename);
     if (ret < 0) {
         bdrv_unref(bs->backing_hd);
         bs->backing_hd = NULL;
@@ -1013,6 +1011,8 @@  int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
         error_propagate(errp, local_err);
         return ret;
     }
+    pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+            bs->backing_hd->file->filename);
     return 0;
 }