[Qemu-trivial] [PATCH] hw/ide: fix a writing to null pointer exception

[忽朝俭]

From b5e5c01b025e83500ca46628add7f63f42f9b2ab Mon Sep 17 00:00:00 2001

From: chaojianhu <address@hidden>

Date: Tue, 2 Aug 2016 17:39:16 +0800

Subject: [PATCH] hw/ide: fix a writing to null pointer exception

In qemu less than v2.1.3, ide_flush_cache calls ide_flush_cb with s->bs == NULL,

and ide_flush_cb calls bdrv_acct_done without checking s->bs neither. Finally, 

bdrv_acct_done writes s->bs directly!

Reported-by: chaojianhu <address@hidden>

Signed-off-by: chaojianhu <address@hidden>

---

 hw/ide/core.c | 4 +++-

 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/ide/core.c b/hw/ide/core.c

index fa4cafa..c39eedc 100644

--- a/hw/ide/core.c

+++ b/hw/ide/core.c

@@ -839,7 +839,9 @@ static void ide_flush_cb(void *opaque, int ret)

         }

     }

 

-    bdrv_acct_done(s->bs, &s->acct);

+    if (s->bs){

+        bdrv_acct_done(s->bs, &s->acct);

+    }

     s->status = READY_STAT | SEEK_STAT;

     ide_async_cmd_done(s);

     ide_set_irq(s->bus);

-- 

1.9.1