Re: [PATCH v2] crypto: ccp - Fix the INIT_EX data file open failure

From: Herbert Xu
Date: Fri Apr 29 2022 - 01:49:03 EST


On Thu, Apr 14, 2022 at 04:23:25PM +0000, Jacky Li wrote:
> There are 2 common cases when INIT_EX data file might not be
> opened successfully and fail the sev initialization:
>
> 1. In user namespaces, normal user tasks (e.g. VMM) can change their
> current->fs->root to point to arbitrary directories. While
> init_ex_path is provided as a module param related to root file
> system. Solution: use the root directory of init_task to avoid
> accessing the wrong file.
>
> 2. Normal user tasks (e.g. VMM) don't have the privilege to access
> the INIT_EX data file. Solution: open the file as root and
> restore permissions immediately.
>
> Fixes: 3d725965f836 ("crypto: ccp - Add SEV_INIT_EX support")
> Signed-off-by: Jacky Li <jackyli@xxxxxxxxxx>
> Reviewed-by: Peter Gonda <pgonda@xxxxxxxxxx>
> ---
> Changelog since v1:
> - Added Fixes tag and Reviewed-By tag.
>
> drivers/crypto/ccp/sev-dev.c | 30 ++++++++++++++++++++++++++++--
> 1 file changed, 28 insertions(+), 2 deletions(-)

Patch applied. Thanks.
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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