check for bs->drv in bdrv_flush (Christoph Hellwig)
authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>
Sun, 29 Mar 2009 01:31:51 +0000 (01:31 +0000)
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>
Sun, 29 Mar 2009 01:31:51 +0000 (01:31 +0000)
commit081501daceca74d2091e798d5dcd342c14d66d1a
tree7e34dccda32b400869ea44ba7cb1be1ec6c1e0c4
parent999dec57f6c7d75176f981d4b5e4df8c30c1c723
check for bs->drv in bdrv_flush (Christoph Hellwig)

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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6943 c046a42c-6fe2-441c-8c8c-71466251a162
block.c