[Qemu-block] ping Re: [PATCH v2] util/async: avoid NULL pointer dereference

[WangJie (Pluto)]

ping

On 2018/6/12 11:32, Jeff Cody wrote:
> On Tue, Jun 12, 2018 at 07:26:25AM +0800, Jie Wang wrote:
>> if laio_init create linux_aio failed and return NULL, NULL pointer
>> dereference will occur when laio_attach_aio_context dereference
>> linux_aio in aio_get_linux_aio. Let's avoid it and report error.
>>
>> Signed-off-by: Jie Wang <address@hidden>
> 
> Reviewed-by: Jeff Cody <address@hidden>
> 
>> ---
>>  block/file-posix.c | 19 +++++++++++++++++--
>>  util/async.c       |  5 ++++-
>>  2 files changed, 21 insertions(+), 3 deletions(-)
>>
>> diff --git a/block/file-posix.c b/block/file-posix.c
>> index 513d371bb1..653017d7a5 100644
>> --- a/block/file-posix.c
>> +++ b/block/file-posix.c
>> @@ -1665,6 +1665,11 @@ static int coroutine_fn raw_co_prw(BlockDriverState 
>> *bs, uint64_t offset,
>>  #ifdef CONFIG_LINUX_AIO
>>          } else if (s->use_linux_aio) {
>>              LinuxAioState *aio = 
>> aio_get_linux_aio(bdrv_get_aio_context(bs));
>> +            if (!aio) {
>> +                s->use_linux_aio = false;
>> +                error_report("Failed to get linux aio");
>> +                return -EIO;
>> +            }
>>              assert(qiov->size == bytes);
>>              return laio_co_submit(bs, aio, s->fd, offset, qiov, type);
>>  #endif
>> @@ -1695,7 +1700,12 @@ static void raw_aio_plug(BlockDriverState *bs)
>>      BDRVRawState *s = bs->opaque;
>>      if (s->use_linux_aio) {
>>          LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
>> -        laio_io_plug(bs, aio);
>> +        if (aio) {
>> +            laio_io_plug(bs, aio);
>> +        } else {
>> +            s->use_linux_aio = false;
>> +            error_report("Failed to get linux aio");
>> +        }
>>      }
>>  #endif
>>  }
>> @@ -1706,7 +1716,12 @@ static void raw_aio_unplug(BlockDriverState *bs)
>>      BDRVRawState *s = bs->opaque;
>>      if (s->use_linux_aio) {
>>          LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
>> -        laio_io_unplug(bs, aio);
>> +        if (aio) {
>> +            laio_io_unplug(bs, aio);
>> +        } else {
>> +            s->use_linux_aio = false;
>> +            error_report("Failed to get linux aio");
>> +        }
>>      }
>>  #endif
>>  }
>> diff --git a/util/async.c b/util/async.c
>> index 03f62787f2..08d71340f8 100644
>> --- a/util/async.c
>> +++ b/util/async.c
>> @@ -327,8 +327,11 @@ LinuxAioState *aio_get_linux_aio(AioContext *ctx)
>>  {
>>      if (!ctx->linux_aio) {
>>          ctx->linux_aio = laio_init();
>> -        laio_attach_aio_context(ctx->linux_aio, ctx);
>> +        if (ctx->linux_aio) {
>> +            laio_attach_aio_context(ctx->linux_aio, ctx);
>> +        }
>>      }
>> +
>>      return ctx->linux_aio;
>>  }
>>  #endif
>> -- 
>> 2.15.0.windows.1
>>
>>
> 
> .
>