[Qemu-devel] [PATCH v2 4/6] block: move string allocation from stack to the heap

[Jeff Cody]

Rather than allocate PATH_MAX bytes on the stack, use g_strndup() to
dynamically allocate the string, and add an exit label for cleanup.

Signed-off-by: Jeff Cody <jc...@redhat.com>
---
 block.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index cbe4a32..39cd7a6 100644
--- a/block.c
+++ b/block.c
@@ -2207,7 +2207,7 @@ int bdrv_commit(BlockDriverState *bs)
     int n, ro, open_flags;
     int ret = 0;
     uint8_t *buf = NULL;
-    char filename[PATH_MAX];
+    char *filename = NULL;
 
     if (!drv)
         return -ENOMEDIUM;
@@ -2222,13 +2222,14 @@ int bdrv_commit(BlockDriverState *bs)
     }
 
     ro = bs->backing_hd->read_only;
-    /* Use pstrcpy (not strncpy): filename must be NUL-terminated. */
-    pstrcpy(filename, sizeof(filename), bs->backing_hd->filename);
+    /* filename must be NUL-terminated. */
+    filename = g_strndup(bs->backing_hd->filename, PATH_MAX - 1);
     open_flags =  bs->backing_hd->open_flags;
 
     if (ro) {
         if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) {
-            return -EACCES;
+            ret = -EACCES;
+            goto exit;
         }
     }
 
@@ -2307,6 +2308,8 @@ ro_cleanup:
         bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL);
     }
 
+exit:
+    g_free(filename);
     return ret;
 }
 
-- 
1.9.3