From: xiakaixu <xiakaixu@huawei.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: <davem@davemloft.net>, <tytso@mit.edu>, <jaegeuk@kernel.org>,
<nhorman@tuxdriver.com>, <ard.biesheuvel@linaro.org>,
<mh1@iki.fi>, <linux-crypto@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, Bintian <bintian.wang@huawei.com>,
<liushuoran@huawei.com>, Huxinwei <huxinwei@huawei.com>,
<zhangzhibin.zhang@huawei.com>
Subject: Re: Kernel panic - encryption/decryption failed when open file on Arm64
Date: Fri, 9 Sep 2016 12:08:51 +0800 [thread overview]
Message-ID: <57D235D3.9010107@huawei.com> (raw)
In-Reply-To: <20160908124709.GA26586@gondor.apana.org.au>
Sorry for resend this email, just add the linux-crypto@vger.kernel.org
and linux-kernel@vger.kernel.org.
Hi,
Firstly, thanks for your reply!
To reproduce this kernel panic, I test the encryption/decryption feature
on arm64 board with more memory. Just add the following
change:
diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index 0122bec..10ef3f4 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -240,6 +240,7 @@ static int blkcipher_walk_next(struct
blkcipher_desc *desc,
walk->flags |= BLKCIPHER_WALK_COPY;
if (!walk->page) {
walk->page = (void
*)__get_free_page(GFP_ATOMIC);
+ walk->page = NULL;
if (!walk->page)
n = 0;
}
This change just set the walk->page to NULL manually.
I get the same crash when open file with the above change log. So I
think this NULL page failure is not be handled correctly in current code.
Regards
Kaixu Xia
> On Thu, Sep 08, 2016 at 08:38:43PM +0800, xiakaixu wrote:
>> Hi,
>>
>> I am using the encryption/decryption feature on arm64 board and a kernel
>> panic occurs just when open a file. As the memory size of the board
>> is limited
>> and there are some page allocation failures before the panic.
>>
>> Seems it is a kernel bug from the call trace log.
>>
>> ...
>> - fscrypt_get_encryption_info
>> - get_crypt_info.part.1
>> - validate_user_key.isra.0
>> - derive_aes_gcm_key
>> - crypto_gcm_decrypt
>> - ablk_decrypt
>> - ctr_encrypt
>> - blkcipher_walk_done
>> - blkcipher_walk_next
>> - __get_free_pages
>> ----------------------------------> page allocation failure
>> ...
>> - aes_ctr_encrypt
>> -----------------------------------------> the input parameter is
>> NULL pointer as the page allocation failure
>>
>>
>> The input parameter of function aes_ctr_encrypt() comes from the
>> /struct blkcipher_walk//
>> //walk/, and this variable /walk /is allocated by the function
>> __get_free_pages(). So if this
>> page allocate failed, the input parameter of function
>> aes_ctr_encrypt() will be NULL. The
>> panic will occurs if we don't check the input parameter.
>>
>> Not sure about this and wish to get your opinions!
>
> If the page allocation fails in blkcipher_walk_next it'll simply
> switch over to processing it block by block. so I don't think the
> warning is related to the crash.
>
> Cheers,
>
next prev parent reply other threads:[~2016-09-09 4:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <57D15BD3.40903@huawei.com>
2016-09-08 12:47 ` Kernel panic - encryption/decryption failed when open file on Arm64 Herbert Xu
2016-09-09 4:08 ` xiakaixu [this message]
2016-09-09 10:19 ` xiakaixu
2016-09-09 10:31 ` Ard Biesheuvel
2016-09-09 10:56 ` Ard Biesheuvel
2016-09-12 2:16 ` liushuoran
2016-09-12 17:40 ` Ard Biesheuvel
2016-09-13 2:05 ` xiakaixu
2016-09-13 6:43 ` Herbert Xu
2016-09-13 7:56 ` Ard Biesheuvel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=57D235D3.9010107@huawei.com \
--to=xiakaixu@huawei.com \
--cc=ard.biesheuvel@linaro.org \
--cc=bintian.wang@huawei.com \
--cc=davem@davemloft.net \
--cc=herbert@gondor.apana.org.au \
--cc=huxinwei@huawei.com \
--cc=jaegeuk@kernel.org \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=liushuoran@huawei.com \
--cc=mh1@iki.fi \
--cc=nhorman@tuxdriver.com \
--cc=tytso@mit.edu \
--cc=zhangzhibin.zhang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox