diff mbox series

crypto: public_key: fix overflow during implicit conversion

Message ID 20210810063954.628244-1-pizhenwei@bytedance.com (mailing list archive)
State Not Applicable
Delegated to: Herbert Xu
Headers show
Series crypto: public_key: fix overflow during implicit conversion | expand

Commit Message

zhenwei pi Aug. 10, 2021, 6:39 a.m. UTC
Hit kernel warning like this, it can be reproduced by verifying 256
bytes datafile by keyctl command.

 WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540 pkcs1pad_verify+0x160/0x190
 ...
 Call Trace:
  public_key_verify_signature+0x282/0x380
  ? software_key_query+0x12d/0x180
  ? keyctl_pkey_params_get+0xd6/0x130
  asymmetric_key_verify_signature+0x66/0x80
  keyctl_pkey_verify+0xa5/0x100
  do_syscall_64+0x35/0xb0
  entry_SYSCALL_64_after_hwframe+0x44/0xae

'.digest_size(u8) = params->in_len(u32)' leads overflow of an u8 value,
so use u32 instead of u8 of digest. And reorder struct
public_key_signature, it could save 8 bytes on a 64 bit machine.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 include/crypto/public_key.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

zhenwei pi Aug. 18, 2021, 8:33 a.m. UTC | #1
PING

On 8/10/21 2:39 PM, zhenwei pi wrote:
> Hit kernel warning like this, it can be reproduced by verifying 256
> bytes datafile by keyctl command.
> 
>   WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540 pkcs1pad_verify+0x160/0x190
>   ...
>   Call Trace:
>    public_key_verify_signature+0x282/0x380
>    ? software_key_query+0x12d/0x180
>    ? keyctl_pkey_params_get+0xd6/0x130
>    asymmetric_key_verify_signature+0x66/0x80
>    keyctl_pkey_verify+0xa5/0x100
>    do_syscall_64+0x35/0xb0
>    entry_SYSCALL_64_after_hwframe+0x44/0xae
> 
> '.digest_size(u8) = params->in_len(u32)' leads overflow of an u8 value,
> so use u32 instead of u8 of digest. And reorder struct
> public_key_signature, it could save 8 bytes on a 64 bit machine.
> 
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>   include/crypto/public_key.h | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
> index 47accec68cb0..f603325c0c30 100644
> --- a/include/crypto/public_key.h
> +++ b/include/crypto/public_key.h
> @@ -38,9 +38,9 @@ extern void public_key_free(struct public_key *key);
>   struct public_key_signature {
>   	struct asymmetric_key_id *auth_ids[2];
>   	u8 *s;			/* Signature */
> -	u32 s_size;		/* Number of bytes in signature */
>   	u8 *digest;
> -	u8 digest_size;		/* Number of bytes in digest */
> +	u32 s_size;		/* Number of bytes in signature */
> +	u32 digest_size;	/* Number of bytes in digest */
>   	const char *pkey_algo;
>   	const char *hash_algo;
>   	const char *encoding;
>
Jarkko Sakkinen Aug. 18, 2021, 12:33 p.m. UTC | #2
On Wed, 2021-08-18 at 16:33 +0800, zhenwei pi wrote:
> PING

Please, do not top-post.

You are lacking Herbert Xu:

$ scripts/get_maintainer.pl crypto/asymmetric_keys/public_key.c 
David Howells <dhowells@redhat.com> (maintainer:ASYMMETRIC KEYS)
Herbert Xu <herbert@gondor.apana.org.au> (maintainer:CRYPTO API)
"David S. Miller" <davem@davemloft.net> (maintainer:CRYPTO API)
keyrings@vger.kernel.org (open list:ASYMMETRIC KEYS)
linux-crypto@vger.kernel.org (open list:CRYPTO API)
linux-kernel@vger.kernel.org (open list)

> On 8/10/21 2:39 PM, zhenwei pi wrote:
> > Hit kernel warning like this, it can be reproduced by verifying 256
> > bytes datafile by keyctl command.
> > 
> >   WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540
> > pkcs1pad_verify+0x160/0x190
> >   ...
> >   Call Trace:
> >    public_key_verify_signature+0x282/0x380
> >    ? software_key_query+0x12d/0x180
> >    ? keyctl_pkey_params_get+0xd6/0x130
> >    asymmetric_key_verify_signature+0x66/0x80
> >    keyctl_pkey_verify+0xa5/0x100
> >    do_syscall_64+0x35/0xb0
> >    entry_SYSCALL_64_after_hwframe+0x44/0xae
> > 
> > '.digest_size(u8) = params->in_len(u32)' leads overflow of an u8

Where is this statement?

> > value,
> > so use u32 instead of u8 of digest. And reorder struct
> > public_key_signature, it could save 8 bytes on a 64 bit machine.
                                                     ~~~~~
                                                     64-bit
                                                     
What do you mean by "could"? Does it, or does it
not?                                                                   
                                       					
	  								
									
		

> > 
> > Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>

Nit: "Firstname Lastname" (first letters capitalized)

> > ---
> >   include/crypto/public_key.h | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/include/crypto/public_key.h
> > b/include/crypto/public_key.h
> > index 47accec68cb0..f603325c0c30 100644
> > --- a/include/crypto/public_key.h
> > +++ b/include/crypto/public_key.h
> > @@ -38,9 +38,9 @@ extern void public_key_free(struct public_key
> > *key);
> >   struct public_key_signature {
> >   	struct asymmetric_key_id *auth_ids[2];
> >   	u8 *s;			/* Signature */
> > -	u32 s_size;		/* Number of bytes in signature */
> >   	u8 *digest;
> > -	u8 digest_size;		/* Number of bytes in digest */
> > +	u32 s_size;		/* Number of bytes in signature */
> > +	u32 digest_size;	/* Number of bytes in digest */
> >   	const char *pkey_algo;
> >   	const char *hash_algo;
> >   	const char *encoding;
> > 

/Jarkko
Herbert Xu Aug. 18, 2021, 11:35 p.m. UTC | #3
On Wed, Aug 18, 2021 at 03:33:32PM +0300, Jarkko Sakkinen wrote:
> On Wed, 2021-08-18 at 16:33 +0800, zhenwei pi wrote:
> > PING
> 
> Please, do not top-post.
> 
> You are lacking Herbert Xu:

I think he already cc'ed me but this patch really belongs to David
Howells' tree.

Thanks,
zhenwei pi Aug. 19, 2021, 2:03 a.m. UTC | #4
On 8/18/21 8:33 PM, Jarkko Sakkinen wrote:
> On Wed, 2021-08-18 at 16:33 +0800, zhenwei pi wrote:
>> PING
> 
> Please, do not top-post.
> 
> You are lacking Herbert Xu:
> 
> $ scripts/get_maintainer.pl crypto/asymmetric_keys/public_key.c
> David Howells <dhowells@redhat.com> (maintainer:ASYMMETRIC KEYS)
> Herbert Xu <herbert@gondor.apana.org.au> (maintainer:CRYPTO API)
> "David S. Miller" <davem@davemloft.net> (maintainer:CRYPTO API)
> keyrings@vger.kernel.org (open list:ASYMMETRIC KEYS)
> linux-crypto@vger.kernel.org (open list:CRYPTO API)
> linux-kernel@vger.kernel.org (open list)
> 
>> On 8/10/21 2:39 PM, zhenwei pi wrote:
>>> Hit kernel warning like this, it can be reproduced by verifying 256
>>> bytes datafile by keyctl command.
>>>
>>>    WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540
>>> pkcs1pad_verify+0x160/0x190
>>>    ...
>>>    Call Trace:
>>>     public_key_verify_signature+0x282/0x380
>>>     ? software_key_query+0x12d/0x180
>>>     ? keyctl_pkey_params_get+0xd6/0x130
>>>     asymmetric_key_verify_signature+0x66/0x80
>>>     keyctl_pkey_verify+0xa5/0x100
>>>     do_syscall_64+0x35/0xb0
>>>     entry_SYSCALL_64_after_hwframe+0x44/0xae
>>>
>>> '.digest_size(u8) = params->in_len(u32)' leads overflow of an u8
> 
> Where is this statement?
> 

In function "static int asymmetric_key_verify_signature(struct 
kernel_pkey_params *params, const void *in, const void *in2)"

>>> value,
>>> so use u32 instead of u8 of digest. And reorder struct
>>> public_key_signature, it could save 8 bytes on a 64 bit machine.
>                                                       ~~~~~
>                                                       64-bit
>                                                       
> What do you mean by "could"? Does it, or does it
> not?
>                                         					
> 
After reordering struct public_key_signature, sizeof(struct 
public_key_signature) gets smaller than the original version.
	  								
> 									
> 		
> 
>>>
>>> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> 
> Nit: "Firstname Lastname" (first letters capitalized)
> 
>>> ---
>>>    include/crypto/public_key.h | 4 ++--
>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/include/crypto/public_key.h
>>> b/include/crypto/public_key.h
>>> index 47accec68cb0..f603325c0c30 100644
>>> --- a/include/crypto/public_key.h
>>> +++ b/include/crypto/public_key.h
>>> @@ -38,9 +38,9 @@ extern void public_key_free(struct public_key
>>> *key);
>>>    struct public_key_signature {
>>>    	struct asymmetric_key_id *auth_ids[2];
>>>    	u8 *s;			/* Signature */
>>> -	u32 s_size;		/* Number of bytes in signature */
>>>    	u8 *digest;
>>> -	u8 digest_size;		/* Number of bytes in digest */
>>> +	u32 s_size;		/* Number of bytes in signature */
>>> +	u32 digest_size;	/* Number of bytes in digest */
>>>    	const char *pkey_algo;
>>>    	const char *hash_algo;
>>>    	const char *encoding;
>>>
> 
> /Jarkko
>
Jarkko Sakkinen Aug. 19, 2021, 10:35 a.m. UTC | #5
On Thu, 2021-08-19 at 10:03 +0800, zhenwei pi wrote:
> On 8/18/21 8:33 PM, Jarkko Sakkinen wrote:
> > On Wed, 2021-08-18 at 16:33 +0800, zhenwei pi wrote:
> > > PING
> > 
> > Please, do not top-post.
> > 
> > You are lacking Herbert Xu:
> > 
> > $ scripts/get_maintainer.pl crypto/asymmetric_keys/public_key.c
> > David Howells <dhowells@redhat.com> (maintainer:ASYMMETRIC KEYS)
> > Herbert Xu <herbert@gondor.apana.org.au> (maintainer:CRYPTO API)
> > "David S. Miller" <davem@davemloft.net> (maintainer:CRYPTO API)
> > keyrings@vger.kernel.org (open list:ASYMMETRIC KEYS)
> > linux-crypto@vger.kernel.org (open list:CRYPTO API)
> > linux-kernel@vger.kernel.org (open list)
> > 
> > > On 8/10/21 2:39 PM, zhenwei pi wrote:
> > > > Hit kernel warning like this, it can be reproduced by verifying
> > > > 256
> > > > bytes datafile by keyctl command.
> > > > 
> > > >    WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540
> > > > pkcs1pad_verify+0x160/0x190
> > > >    ...
> > > >    Call Trace:
> > > >     public_key_verify_signature+0x282/0x380
> > > >     ? software_key_query+0x12d/0x180
> > > >     ? keyctl_pkey_params_get+0xd6/0x130
> > > >     asymmetric_key_verify_signature+0x66/0x80
> > > >     keyctl_pkey_verify+0xa5/0x100
> > > >     do_syscall_64+0x35/0xb0
> > > >     entry_SYSCALL_64_after_hwframe+0x44/0xae
> > > > 
> > > > '.digest_size(u8) = params->in_len(u32)' leads overflow of an
> > > > u8
> > 
> > Where is this statement?
> > 
> 
> In function "static int asymmetric_key_verify_signature(struct 
> kernel_pkey_params *params, const void *in, const void *in2)"
> 
> > > > value,
> > > > so use u32 instead of u8 of digest. And reorder struct
> > > > public_key_signature, it could save 8 bytes on a 64 bit
> > > > machine.
> >                                                       ~~~~~
> >                                                       64-bit
> >                                                       
> > What do you mean by "could"? Does it, or does it
> > not?
> >                                         				
> > 	
> > 
> After reordering struct public_key_signature, sizeof(struct 
> public_key_signature) gets smaller than the original version.

OK, then just state is as "it saves" instead of "it could save".

Not a requirement but have you been able to trigger this for a
kernel that does not have this fix?

/Jarkko
zhenwei pi Aug. 19, 2021, 10:52 a.m. UTC | #6
On 8/19/21 6:35 PM, Jarkko Sakkinen wrote:
> On Thu, 2021-08-19 at 10:03 +0800, zhenwei pi wrote:
>> On 8/18/21 8:33 PM, Jarkko Sakkinen wrote:
>>> On Wed, 2021-08-18 at 16:33 +0800, zhenwei pi wrote:
>>>> PING
>>>
>>> Please, do not top-post.
>>>
>>> You are lacking Herbert Xu:
>>>
>>> $ scripts/get_maintainer.pl crypto/asymmetric_keys/public_key.c
>>> David Howells <dhowells@redhat.com> (maintainer:ASYMMETRIC KEYS)
>>> Herbert Xu <herbert@gondor.apana.org.au> (maintainer:CRYPTO API)
>>> "David S. Miller" <davem@davemloft.net> (maintainer:CRYPTO API)
>>> keyrings@vger.kernel.org (open list:ASYMMETRIC KEYS)
>>> linux-crypto@vger.kernel.org (open list:CRYPTO API)
>>> linux-kernel@vger.kernel.org (open list)
>>>
>>>> On 8/10/21 2:39 PM, zhenwei pi wrote:
>>>>> Hit kernel warning like this, it can be reproduced by verifying
>>>>> 256
>>>>> bytes datafile by keyctl command.
>>>>>
>>>>>     WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540
>>>>> pkcs1pad_verify+0x160/0x190
>>>>>     ...
>>>>>     Call Trace:
>>>>>      public_key_verify_signature+0x282/0x380
>>>>>      ? software_key_query+0x12d/0x180
>>>>>      ? keyctl_pkey_params_get+0xd6/0x130
>>>>>      asymmetric_key_verify_signature+0x66/0x80
>>>>>      keyctl_pkey_verify+0xa5/0x100
>>>>>      do_syscall_64+0x35/0xb0
>>>>>      entry_SYSCALL_64_after_hwframe+0x44/0xae
>>>>>
>>>>> '.digest_size(u8) = params->in_len(u32)' leads overflow of an
>>>>> u8
>>>
>>> Where is this statement?
>>>
>>
>> In function "static int asymmetric_key_verify_signature(struct
>> kernel_pkey_params *params, const void *in, const void *in2)"
>>
>>>>> value,
>>>>> so use u32 instead of u8 of digest. And reorder struct
>>>>> public_key_signature, it could save 8 bytes on a 64 bit
>>>>> machine.
>>>                                                        ~~~~~
>>>                                                        64-bit
>>>                                                        
>>> What do you mean by "could"? Does it, or does it
>>> not?
>>>                                          				
>>> 	
>>>
>> After reordering struct public_key_signature, sizeof(struct
>> public_key_signature) gets smaller than the original version.
> 
> OK, then just state is as "it saves" instead of "it could save".
> 
> Not a requirement but have you been able to trigger this for a
> kernel that does not have this fix?
> 
This kernel warning can be reproduced on debian11(Linux-5.10.0-8-amd64) 
by the following script:

RAWDATA=rawdata
SIGDATA=sigdata

modprobe pkcs8_key_parser

rm -rf *.der *.pem *.pfx
rm -rf $RAWDATA
dd if=/dev/random of=$RAWDATA bs=256 count=1

openssl req -nodes -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem 
-subj "/C=CN/ST=GD/L=SZ/O=vihoo/OU=dev/CN=xx.com/emailAddress=yy@xx.com"

KEY_ID=`openssl pkcs8 -in key.pem -topk8 -nocrypt -outform DER | keyctl 
padd asymmetric 123 @s`

keyctl pkey_sign $KEY_ID 0 $RAWDATA enc=pkcs1 hash=sha1 > $SIGDATA
keyctl pkey_verify $KEY_ID 0 $RAWDATA $SIGDATA enc=pkcs1 hash=sha1


> /Jarkko
>
Jarkko Sakkinen Aug. 19, 2021, 11:44 a.m. UTC | #7
On Thu, 2021-08-19 at 18:52 +0800, zhenwei pi wrote:
> On 8/19/21 6:35 PM, Jarkko Sakkinen wrote:
> > On Thu, 2021-08-19 at 10:03 +0800, zhenwei pi wrote:
> > > On 8/18/21 8:33 PM, Jarkko Sakkinen wrote:
> > > > On Wed, 2021-08-18 at 16:33 +0800, zhenwei pi wrote:
> > > > > PING
> > > > 
> > > > Please, do not top-post.
> > > > 
> > > > You are lacking Herbert Xu:
> > > > 
> > > > $ scripts/get_maintainer.pl crypto/asymmetric_keys/public_key.c
> > > > David Howells <dhowells@redhat.com> (maintainer:ASYMMETRIC KEYS)
> > > > Herbert Xu <herbert@gondor.apana.org.au> (maintainer:CRYPTO API)
> > > > "David S. Miller" <davem@davemloft.net> (maintainer:CRYPTO API)
> > > > keyrings@vger.kernel.org (open list:ASYMMETRIC KEYS)
> > > > linux-crypto@vger.kernel.org (open list:CRYPTO API)
> > > > linux-kernel@vger.kernel.org (open list)
> > > > 
> > > > > On 8/10/21 2:39 PM, zhenwei pi wrote:
> > > > > > Hit kernel warning like this, it can be reproduced by verifying
> > > > > > 256
> > > > > > bytes datafile by keyctl command.
> > > > > > 
> > > > > >     WARNING: CPU: 5 PID: 344556 at crypto/rsa-pkcs1pad.c:540
> > > > > > pkcs1pad_verify+0x160/0x190
> > > > > >     ...
> > > > > >     Call Trace:
> > > > > >      public_key_verify_signature+0x282/0x380
> > > > > >      ? software_key_query+0x12d/0x180
> > > > > >      ? keyctl_pkey_params_get+0xd6/0x130
> > > > > >      asymmetric_key_verify_signature+0x66/0x80
> > > > > >      keyctl_pkey_verify+0xa5/0x100
> > > > > >      do_syscall_64+0x35/0xb0
> > > > > >      entry_SYSCALL_64_after_hwframe+0x44/0xae
> > > > > > 
> > > > > > '.digest_size(u8) = params->in_len(u32)' leads overflow of an
> > > > > > u8
> > > > 
> > > > Where is this statement?
> > > > 
> > > 
> > > In function "static int asymmetric_key_verify_signature(struct
> > > kernel_pkey_params *params, const void *in, const void *in2)"
> > > 
> > > > > > value,
> > > > > > so use u32 instead of u8 of digest. And reorder struct
> > > > > > public_key_signature, it could save 8 bytes on a 64 bit
> > > > > > machine.
> > > >                                                        ~~~~~
> > > >                                                        64-bit
> > > >                                                        
> > > > What do you mean by "could"? Does it, or does it
> > > > not?
> > > >                                          				
> > > > 	
> > > > 
> > > After reordering struct public_key_signature, sizeof(struct
> > > public_key_signature) gets smaller than the original version.
> > 
> > OK, then just state is as "it saves" instead of "it could save".
> > 
> > Not a requirement but have you been able to trigger this for a
> > kernel that does not have this fix?
> > 
> This kernel warning can be reproduced on debian11(Linux-5.10.0-8-amd64) 
> by the following script:
> 
> RAWDATA=rawdata
> SIGDATA=sigdata
> 
> modprobe pkcs8_key_parser
> 
> rm -rf *.der *.pem *.pfx
> rm -rf $RAWDATA
> dd if=/dev/random of=$RAWDATA bs=256 count=1
> 
> openssl req -nodes -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem 
> -subj "/C=CN/ST=GD/L=SZ/O=vihoo/OU=dev/CN=xx.com/emailAddress=yy@xx.com"
> 
> KEY_ID=`openssl pkcs8 -in key.pem -topk8 -nocrypt -outform DER | keyctl 
> padd asymmetric 123 @s`
> 
> keyctl pkey_sign $KEY_ID 0 $RAWDATA enc=pkcs1 hash=sha1 > $SIGDATA
> keyctl pkey_verify $KEY_ID 0 $RAWDATA $SIGDATA enc=pkcs1 hash=sha1


Thank you. I'll see if I can reproduce this when you send a new version
(if not, it is not constraint for accepting to patch, but I'll still
try).

PS. Ignore the firstname lastname comment. I was not aware that in some
cultures it is written like that (James Bottomley pointed this out).

/Jarkko
diff mbox series

Patch

diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 47accec68cb0..f603325c0c30 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -38,9 +38,9 @@  extern void public_key_free(struct public_key *key);
 struct public_key_signature {
 	struct asymmetric_key_id *auth_ids[2];
 	u8 *s;			/* Signature */
-	u32 s_size;		/* Number of bytes in signature */
 	u8 *digest;
-	u8 digest_size;		/* Number of bytes in digest */
+	u32 s_size;		/* Number of bytes in signature */
+	u32 digest_size;	/* Number of bytes in digest */
 	const char *pkey_algo;
 	const char *hash_algo;
 	const char *encoding;