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@xxxxxxxxxxxxxxx
> Reported-by: Andy Nguyen <theflow@xxxxxxxxxx>
> Suggested-by: David Rientjes <rientjes@xxxxxxxxxx>
> Suggested-by: Peter Gonda <pgonda@xxxxxxxxxx>
> Signed-off-by: John Allen <john.allen@xxxxxxx>
> ---
> v2:
> - Add fixes tags and CC stable@xxxxxxxxxxxxxxx
> 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@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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