Re: [PATCH v2 02/10] pseries/plpks: fix error handling in plpks_read_var()
From: R Nageswara Sastry <hidden>
Date: 2026-09-04 06:11:25
Also in:
keyrings, linux-integrity, linux-security-module, lkml
On 31.08.2026 4:47 PM, Srish Srinivasan wrote:
When a plpks variable is initialized without a policy and used to read an
object with the 'wrapping key' policy set, the hypervisor returns
H_AUTHORITY along with the object's policy. However, plpks_read_var() at
present 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 only propagate
policy information when it is returned alongside H_AUTHORITY by the
hypervisor. Remove the explicit assignment of rc to zero in the case of
H_SUCCESS as it is redundant.
Also return -EPERM instead of -EINVAL when the 'wrapping key' policy bit is
set by the caller, better reflecting the access restriction being enforced.
Fixes: 2454a7af0f2a ("powerpc/pseries: define driver for Platform KeyStore")
Fixes: 133aa79e211d ("pseries/plpks: add HCALLs for PowerVM Key Wrapping Module")
Cc: stable@vger.kernel.org
Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>Tested-by: R Nageswara Sastry <redacted> Tested on ppc64le PowerVM LPARs on firmware with wrap/unwrap support, with and without Secure Boot enabled. Verified that PKWM initialisation succeeds and the trusted key seal/unseal round-trip works correctly. Confirmed that -EPERM is now returned (instead of -EINVAL) when a read is attempted on an object with the wrapping key policy bit set. The full key lifecycle (create, export, reload) passed on all configurations.
quoted hunk ↗ jump to hunk
--- arch/powerpc/platforms/pseries/plpks.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c index 23e4e2a922fc..7bd5c149dd09 100644 --- a/arch/powerpc/platforms/pseries/plpks.c +++ b/arch/powerpc/platforms/pseries/plpks.c@@ -826,7 +826,7 @@ static int plpks_read_var(u8 consumer, struct plpks_var *var) return -EINVAL; if (var->policy & PLPKS_WRAPPINGKEY) - return -EINVAL; + return -EPERM; auth = construct_auth(consumer); if (IS_ERR(auth))@@ -856,22 +856,21 @@ 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:
-- Thanks and Regards R.Nageswara Sastry