From: Kevin Wolf <kwolf@redhat.com>
To: Hikaru Nishida <hikarupsp@gmail.com>
Cc: qemu-devel@nongnu.org, "open list:vvfat" <qemu-block@nongnu.org>,
Max Reitz <mreitz@redhat.com>
Subject: Re: [PATCH] block/vvfat: Do not unref qcow on closing backing bdrv
Date: Fri, 14 Feb 2020 14:12:22 +0100 [thread overview]
Message-ID: <20200214131222.GC5443@linux.fritz.box> (raw)
In-Reply-To: <20200209175156.85748-1-hikarupsp@gmail.com>
Am 09.02.2020 um 18:51 hat Hikaru Nishida geschrieben:
> Before this commit, BDRVVVFATState.qcow is unrefed in write_target_close
> on closing backing bdrv of vvfat. However, qcow bdrv is opend as a child
> of vvfat in enable_write_target() so it will be also unrefed on closing
> vvfat itself. This causes use-after-free of qcow on freeing vvfat which
> has backing bdrv and qcow bdrv as children in this order because
> bdrv_close(vvfat) tries to free qcow bdrv after freeing backing bdrv
> as QLIST_FOREACH_SAFE() loop keeps next pointer, but BdrvChild of qcow
> is already freed in bdrv_close(backing bdrv).
>
> Signed-off-by: Hikaru Nishida <hikarupsp@gmail.com>
Thanks, applied to the block branch.
Kevin
prev parent reply other threads:[~2020-02-14 13:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-09 17:51 [PATCH] block/vvfat: Do not unref qcow on closing backing bdrv Hikaru Nishida
2020-02-14 13:12 ` Kevin Wolf [this message]
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