[PREVIEW] [PATCH] staging: erofs: fix potential overflow in z_erofs_vle_normalaccess_readpage{,s}

[Gao Xiang]

Hi Chao,

On 2018/8/23 19:02, Chao Yu wrote:
> On 2018/8/23 17:19, Gao Xiang wrote:
>> As Dan reported in the LKP mailing list:
>> https://lists.01.org/pipermail/kbuild-all/2018-August/051558.html
>>
>> New smatch warnings:
>> drivers/staging/erofs/unzip_vle.c:1359 z_erofs_vle_normalaccess_readpages() warn: should '()->index << 12' be a 64 bit type?
>>
>> Old smatch warnings:
>> drivers/staging/erofs/unzip_vle.c:1322 z_erofs_vle_normalaccess_readpage() warn: should 'page->index << 12' be a 64 bit type?
>>
>> It needs to cast variable's type to erofs_off_t before left shifting.
>>
>> Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
>> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
> 
> Reviewed-by: Chao Yu <yuchao0 at huawei.com>
> 
>> ---
>>
>> Hi Chao,
>>
>> This patch is based on
>> `staging: erofs: fix potential overflow in erofs_grab_bio()'
>> in order to avoid patch conflict when rebasing.
>>
>> I think it is better to rearrange the commit order in the erofs branch and
>> it needs to be sent separately in advance to Greg.
> 
> Agreed, let me add this into erofs branch later.
> 
> Thanks,

OK, I will send to Greg appended to the upstream commit
`staging: erofs: fix potential overflow in erofs_grab_bio()`
after you add this into erofs branch and receive the successful daily lkp report.

Thanks,
Gao XIang

> 
>>
>> Thanks,
>> Gao Xiang
>>
>>  drivers/staging/erofs/unzip_vle.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
>> index 6c4c928..22f9a02 100644
>> --- a/drivers/staging/erofs/unzip_vle.c
>> +++ b/drivers/staging/erofs/unzip_vle.c
>> @@ -1314,7 +1314,7 @@ static int z_erofs_vle_normalaccess_readpage(struct file *file,
>>  	LIST_HEAD(pagepool);
>>  
>>  #if (EROFS_FS_ZIP_CACHE_LVL >= 2)
>> -	f.cachedzone_la = page->index << PAGE_SHIFT;
>> +	f.cachedzone_la = (erofs_off_t)page->index << PAGE_SHIFT;
>>  #endif
>>  	err = z_erofs_do_read_page(&f, page, &pagepool);
>>  	(void)z_erofs_vle_work_iter_end(&f.builder);
>> @@ -1347,7 +1347,7 @@ static inline int __z_erofs_vle_normalaccess_readpages(
>>  	LIST_HEAD(pagepool);
>>  
>>  #if (EROFS_FS_ZIP_CACHE_LVL >= 2)
>> -	f.cachedzone_la = lru_to_page(pages)->index << PAGE_SHIFT;
>> +	f.cachedzone_la = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT;
>>  #endif
>>  	for (; nr_pages; --nr_pages) {
>>  		struct page *page = lru_to_page(pages);
>>
>