From: John Hubbard <jhubbard@nvidia.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <keescook@chromium.org>
Cc: kernel test robot <lkp@intel.com>,
Matt Porter <mporter@kernel.crashing.org>,
Alexandre Bounine <alex.bou9@gmail.com>,
Jing Xiangfeng <jingxiangfeng@huawei.com>,
Ira Weiny <ira.weiny@intel.com>,
Souptick Joarder <jrdr.linux@gmail.com>,
"Gustavo A . R . Silva" <gustavoars@kernel.org>,
Dan Carpenter <dan.carpenter@oracle.com>,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH] rapidio: Avoid bogus __alloc_size warning
Date: Thu, 9 Sep 2021 15:26:43 -0700 [thread overview]
Message-ID: <5cdc5c42-e218-7be5-a2e9-2c412bb8a840@nvidia.com> (raw)
In-Reply-To: <20210909132752.4bde36ccf50720e56160f00c@linux-foundation.org>
On 9/9/21 13:27, Andrew Morton wrote:
...
>> include/linux/thread_info.h:213:4: error: call to '__bad_copy_to' declared with attribute error: copy destination size is too small
>> 213 | __bad_copy_to();
>> | ^~~~~~~~~~~~~~~
>>
>> But the allocation size and the copy size are identical:
>>
>> transfer = vmalloc(array_size(sizeof(*transfer), transaction.count));
>> if (!transfer)
>> return -ENOMEM;
>>
>> if (unlikely(copy_from_user(transfer,
>> (void __user *)(uintptr_t)transaction.block,
>> array_size(sizeof(*transfer), transaction.count)))) {
>
> That's an "error", not a warning. Or is this thanks to the new -Werror?
>
> Either way, I'm inclined to cc:stable on this, because use of gcc-9 on
> older kernels will be a common thing down the ages.
>
> If it's really an "error" on non-Werror kernels then definitely cc:stable.
>
It looks like a hard error, not a warning upgraded by -Werror: I did a local
repro, then ran with V=1, removed all -Werror parts of the gcc invocation,
ran again, and still reproduced the error.
I also verified that the patch causes the error to go away.
Also, I can't find anything wrong with the diffs, so:
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
thanks,
--
John Hubbard
NVIDIA
next prev parent reply other threads:[~2021-09-09 22:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-09 16:14 [PATCH] rapidio: Avoid bogus __alloc_size warning Kees Cook
2021-09-09 20:27 ` Andrew Morton
2021-09-09 22:26 ` John Hubbard [this message]
2021-09-09 22:51 ` Kees Cook
2021-09-09 23:11 ` Andrew Morton
2021-09-10 1:52 ` Kees Cook
2021-09-10 4:50 ` Dan Carpenter
2021-09-10 5:48 ` Andrew Morton
2021-09-10 6:29 ` Kees Cook
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