Re: [Qemu-devel] [PATCH 2/2] qcow2: Avoid making the L1 table too big

From: Max Reitz <mreitz@redhat.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, qemu-stable@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 2/2] qcow2: Avoid making the L1 table too big
Date: Wed, 6 Jul 2016 14:47:29 +0200	[thread overview]
Message-ID: <1a0e01ee-fdcd-3428-c2de-7ea8e50dc5a6@redhat.com> (raw)
In-Reply-To: <20160706084015.GF5233@noname.str.redhat.com>

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On 06.07.2016 10:40, Kevin Wolf wrote:
> Am 15.06.2016 um 17:36 hat Max Reitz geschrieben:
>> We refuse to open images whose L1 table we deem "too big". Consequently,
>> we should not produce such images ourselves.
>>
>> Cc: qemu-stable@nongnu.org
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>  block/qcow2-cluster.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
>> index 893ddf6..335b9b0 100644
>> --- a/block/qcow2-cluster.c
>> +++ b/block/qcow2-cluster.c
>> @@ -65,7 +65,7 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
>>          }
>>      }
>>  
>> -    if (new_l1_size > INT_MAX / sizeof(uint64_t)) {
>> +    if (new_l1_size > QCOW_MAX_L1_SIZE / sizeof(uint64_t)) {
>>          return -EFBIG;
>>      }
> 
> Maybe add a QEMU_BUILD_BUG_ON(QCOW_MAX_L1_SIZE > INT_MAX)?

Good idea, did that. I changed it directly in my block branch, or do you
think a v2 mail necessary?

Max

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