When a PLPKS variable is initialized without a policy and used to read an
object with the PLPKS_WRAPPINGKEY policy set, the hypervisor returns
H_AUTHORITY along with the object's policy. However, plpks_read_var()
currently treats this the same as any other H_AUTHORITY failure and returns
an error without propagating the policy information to the caller.
Distinguish this case from other H_AUTHORITY failures and propagate the
returned policy to the caller while preserving the authorization error.
Remove the explicit assignment of zero to rc on H_SUCCESS, as it is
redundant.
Also validate the PLPKS variable pointer before dereferencing it.
Fixes: 2454a7af0f2a ("powerpc/pseries: define driver for Platform KeyStore")
Cc: [email protected] # 6.0
Signed-off-by: Srish Srinivasan <[email protected]>
Tested-by: R Nageswara Sastry <[email protected]>
---
arch/powerpc/platforms/pseries/plpks.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/plpks.c
b/arch/powerpc/platforms/pseries/plpks.c
index 23e4e2a922fc..7e56b3dcacbc 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -822,6 +822,9 @@ static int plpks_read_var(u8 consumer, struct plpks_var
*var)
u8 *output;
int rc;
+ if (!var)
+ return -EINVAL;
+
if (var->namelen > PLPKS_MAX_NAME_SIZE)
return -EINVAL;
@@ -856,22 +859,21 @@ static int plpks_read_var(u8 consumer, struct plpks_var
*var)
virt_to_phys(var->name), var->namelen,
virt_to_phys(output),
maxobjsize);
-
if (rc != H_SUCCESS) {
rc = pseries_status_to_err(rc);
- goto out_free_output;
+ if (rc != -EPERM || !retbuf[1])
+ goto out_free_output;
+ goto out_copy_policy;
}
if (!var->data || var->datalen > retbuf[0])
var->datalen = retbuf[0];
- var->policy = retbuf[1];
-
if (var->data)
memcpy(var->data, output, var->datalen);
- rc = 0;
-
+out_copy_policy:
+ var->policy = retbuf[1];
out_free_output:
kfree(output);
out_free_label:
--
2.52.0
