From: Christoph Hellwig <hch@lst.de>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [PATCH] check for bs->drv in bdrv_flush
Date: Sat, 28 Mar 2009 19:39:16 +0100 [thread overview]
Message-ID: <20090328183916.GA25875@lst.de> (raw)
All the bdrv_ helpers should check for bs->drv being zero as that means
there is no backend image open. bdrv_flush fails to perform that check
and can thus cause NULL pointer dereferences.
Found using qemu-io.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Index: qemu/block.c
===================================================================
--- qemu.orig/block.c 2009-03-19 21:48:12.180978074 +0100
+++ qemu/block.c 2009-03-19 21:48:53.228977807 +0100
@@ -979,6 +979,8 @@ const char *bdrv_get_device_name(BlockDr
void bdrv_flush(BlockDriverState *bs)
{
+ if (!bs->drv)
+ return;
if (bs->drv->bdrv_flush)
bs->drv->bdrv_flush(bs);
if (bs->backing_hd)
next reply other threads:[~2009-03-28 18:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-28 18:39 Christoph Hellwig [this message]
2009-03-29 1:32 ` [Qemu-devel] [PATCH] check for bs->drv in bdrv_flush Anthony Liguori
2009-03-29 7:31 ` Christoph Hellwig
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