From: Laszlo Ersek <lersek@redhat.com>
To: Bug 865518 <865518@bugs.launchpad.net>
Cc: Richard Jones <rjones@redhat.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [Bug 865518] Re: qemu segfaults when writing to very large qcow2 disk
Date: Mon, 13 May 2013 09:11:46 +0200 [thread overview]
Message-ID: <51909232.3020000@redhat.com> (raw)
In-Reply-To: <20130511081617.17399.58157.malone@wampee.canonical.com>
On 05/11/13 10:16, Richard Jones wrote:
> Still happening in upstream qemu from git:
>
> Program terminated with signal 11, Segmentation fault.
> #0 0x00007f4f86c721a0 in get_cluster_table (bs=bs@entry=0x7f4f886e7880,
> offset=offset@entry=1152921504606834688,
> new_l2_table=new_l2_table@entry=0x7f4f8ad9a0b0,
> new_l2_index=new_l2_index@entry=0x7f4f8ad9a0ac)
> at block/qcow2-cluster.c:525
> 525 l2_offset = s->l1_table[l1_index] & L1E_OFFSET_MASK;
Supposing that line 517 doesn't overflow "l1_index" for starters (which
is an uint32_t in practice), line 519 converts "l1_index + 1" to "signed
int". If the "min_size" parameter of qcow2_grow_l1_table() is negative,
then the function won't do anything.
Laszlo
next prev parent reply other threads:[~2013-05-13 7:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-03 16:46 [Qemu-devel] [Bug 865518] [NEW] qemu segfaults when writing to very large qcow2 disk Richard W.M. Jones
2013-05-11 8:16 ` [Qemu-devel] [Bug 865518] " Richard Jones
2013-05-13 7:11 ` Laszlo Ersek [this message]
2013-05-11 8:19 ` Richard Jones
2016-06-22 15:47 ` T. Huth
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