[PATCH] fixup! s390/zcrypt: Rework cca findcard() implementation and callers

[PATCH] fixup! s390/zcrypt: Rework cca findcard() implementation and callers

[Harald Freudenberger]

Ci run of the night showed that a CCA secure key which maches
to an old MK on the HSM is not correctly verified. The code
builds up an array with a given apqn array with a fixed arraysize
and calls findcard2() for the CURRENT MK which fails as expected.
So next attempt is made with trying to match the OLD MK with same
apqn array and same arraysize variable. But the previous call hat
set this arraysize variable to 0 and so the 2nd invocation finds
a valid apqn but the arraysize variable tells there is no space
in the array. Fixed and tested.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reported-by: Ingo Franzki ifranzki@linux.ibm.com
---
 drivers/s390/crypto/pkey_cca.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/s390/crypto/pkey_cca.c b/drivers/s390/crypto/pkey_cca.c
index fe67946edc9d..6c7897a93f27 100644
--- a/drivers/s390/crypto/pkey_cca.c
+++ b/drivers/s390/crypto/pkey_cca.c
@@ -487,6 +487,7 @@ static int cca_verifykey(const u8 *key, u32 keylen,
 		if (!rc)
 			*flags = PKEY_FLAGS_MATCH_CUR_MKVP;
 		if (rc == -ENODEV) {
+			nr_apqns = ARRAY_SIZE(apqns);
 			rc = cca_findcard2(apqns, &nr_apqns, *card, *dom,
 					   ZCRYPT_CEX3C, AES_MK_SET,
 					   0, t->mkvp, xflags);
@@ -520,6 +521,7 @@ static int cca_verifykey(const u8 *key, u32 keylen,
 		if (!rc)
 			*flags = PKEY_FLAGS_MATCH_CUR_MKVP;
 		if (rc == -ENODEV) {
+			nr_apqns = ARRAY_SIZE(apqns);
 			rc = cca_findcard2(apqns, &nr_apqns, *card, *dom,
 					   ZCRYPT_CEX6, AES_MK_SET,
 					   0, t->mkvp0, xflags);
-- 
2.43.0

Re: [PATCH] fixup! s390/zcrypt: Rework cca findcard() implementation and callers

[Heiko Carstens]

On Fri, Apr 25, 2025 at 04:39:47PM +0200, Harald Freudenberger wrote:
> Ci run of the night showed that a CCA secure key which maches
> to an old MK on the HSM is not correctly verified. The code
> builds up an array with a given apqn array with a fixed arraysize
> and calls findcard2() for the CURRENT MK which fails as expected.
> So next attempt is made with trying to match the OLD MK with same
> apqn array and same arraysize variable. But the previous call hat
> set this arraysize variable to 0 and so the 2nd invocation finds
> a valid apqn but the arraysize variable tells there is no space
> in the array. Fixed and tested.
> 
> Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
> Reported-by: Ingo Franzki ifranzki@linux.ibm.com
> ---
>  drivers/s390/crypto/pkey_cca.c | 2 ++
>  1 file changed, 2 insertions(+)

Merged into your previous patch. Thanks!