linux-kernel - Re: [PATCH v4] crypto: ccp - Use kzalloc for sev ioctl interfaces to prevent kernel memory leak

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <YqMLUOQtcsNwU6xw@gondor.apana.org.au>
Date:   Fri, 10 Jun 2022 17:13:52 +0800
From:   Herbert Xu <herbert@...dor.apana.org.au>
To:     John Allen <john.allen@....com>
Cc:     linux-crypto@...r.kernel.org, seanjc@...gle.com,
        Thomas.Lendacky@....com, Ashish.Kalra@....com,
        linux-kernel@...r.kernel.org, theflow@...gle.com,
        rientjes@...gle.com, pgonda@...gle.com, stable@...r.kernel.org
Subject: Re: [PATCH v4] crypto: ccp - Use kzalloc for sev ioctl interfaces to
 prevent kernel memory leak

On Wed, May 18, 2022 at 03:31:26PM +0000, John Allen wrote:
> For some sev ioctl interfaces, input may be passed that is less than or
> equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data that PSP
> firmware returns. In this case, kmalloc will allocate memory that is the
> size of the input rather than the size of the data. Since PSP firmware
> doesn't fully overwrite the buffer, the sev ioctl interfaces with the
> issue may return uninitialized slab memory.
> 
> Currently, all of the ioctl interfaces in the ccp driver are safe, but
> to prevent future problems, change all ioctl interfaces that allocate
> memory with kmalloc to use kzalloc and memset the data buffer to zero
> in sev_ioctl_do_platform_status.
> 
> Fixes: 38103671aad3 ("crypto: ccp: Use the stack and common buffer for status commands")
> Fixes: e799035609e15 ("crypto: ccp: Implement SEV_PEK_CSR ioctl command")
> Fixes: 76a2b524a4b1d ("crypto: ccp: Implement SEV_PDH_CERT_EXPORT ioctl command")
> Fixes: d6112ea0cb344 ("crypto: ccp - introduce SEV_GET_ID2 command")
> Cc: stable@...r.kernel.org
> Reported-by: Andy Nguyen <theflow@...gle.com>
> Suggested-by: David Rientjes <rientjes@...gle.com>
> Suggested-by: Peter Gonda <pgonda@...gle.com>
> Signed-off-by: John Allen <john.allen@....com>
> ---
> v2:
>   - Add fixes tags and CC stable@...r.kernel.org
> v3:
>   - memset data buffer to zero in sev_ioctl_do_platform_status
> v4:
>   - Add fixes tag for sev_ioctl_do_platform_status change
> ---
>  drivers/crypto/ccp/sev-dev.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt