Re: [PATCH] libnvdimm/security: Fix key lookup permissions

[Ira Weiny]

On Tue, Jun 23, 2020 at 09:35:26PM -0700, Dan Williams wrote:
> As of commit 8c0637e950d6 ("keys: Make the KEY_NEED_* perms an enum rather
> than a mask") lookup_user_key() needs an explicit declaration of what it
> wants to do with the key. Add KEY_NEED_SEARCH to fix a warning with the
> below signature, and fixes the inability to retrieve a key.
> 
>     WARNING: CPU: 15 PID: 6276 at security/keys/permission.c:35 key_task_permission+0xd3/0x140
>     [..]
>     RIP: 0010:key_task_permission+0xd3/0x140
>     [..]
>     Call Trace:
>      lookup_user_key+0xeb/0x6b0
>      ? vsscanf+0x3df/0x840
>      ? key_validate+0x50/0x50
>      ? key_default_cmp+0x20/0x20
>      nvdimm_get_user_key_payload.part.0+0x21/0x110 [libnvdimm]
>      nvdimm_security_store+0x67d/0xb20 [libnvdimm]
>      security_store+0x67/0x1a0 [libnvdimm]
>      kernfs_fop_write+0xcf/0x1c0
>      vfs_write+0xde/0x1d0
>      ksys_write+0x68/0xe0
>      do_syscall_64+0x5c/0xa0
>      entry_SYSCALL_64_after_hwframe+0x49/0xb3
> 
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
> Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>

Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>

> Suggested-by: David Howells <dhowells@xxxxxxxxxx>
> Fixes: 8c0637e950d6 ("keys: Make the KEY_NEED_* perms an enum rather than a mask")
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
>  drivers/nvdimm/security.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c
> index 89b85970912d..4cef69bd3c1b 100644
> --- a/drivers/nvdimm/security.c
> +++ b/drivers/nvdimm/security.c
> @@ -95,7 +95,7 @@ static struct key *nvdimm_lookup_user_key(struct nvdimm *nvdimm,
>  	struct encrypted_key_payload *epayload;
>  	struct device *dev = &nvdimm->dev;
>  
> -	keyref = lookup_user_key(id, 0, 0);
> +	keyref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
>  	if (IS_ERR(keyref))
>  		return NULL;
>  
>