Re: [PATCH v8 07/12] KEYS: trusted: Remove dead branch from tpm2_unseal_cmd

[Jonathan McDowell]

On Tue, Dec 16, 2025 at 11:21:41AM +0200, Jarkko Sakkinen wrote:

TPM2_Unseal requires TPM2_ST_SESSIONS, and tpm2_unseal_cmd() always does
set up either password or HMAC session.

Remove the branch in tpm2_unseal_cmd() conditionally setting
TPM2_ST_NO_SESSIONS. It is faulty but luckily it is never exercised at
run-time, and thus does not cause regressions.

Reviewed-by: Jonathan McDowell <nood...@meta.com>

Signed-off-by: Jarkko Sakkinen <jar...@kernel.org>
---
security/keys/trusted-keys/trusted_tpm2.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/security/keys/trusted-keys/trusted_tpm2.c 
b/security/keys/trusted-keys/trusted_tpm2.c
index d3a5c5f2b926..3666e3e48eab 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -451,10 +451,8 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
                           struct trusted_key_options *options,
                           u32 blob_handle)
{
-       struct tpm_header *head;
        struct tpm_buf buf;
        u16 data_len;
-       int offset;
        u8 *data;
        int rc;

@@ -495,14 +493,8 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
                tpm_buf_append_u16(&buf, options->blobauth_len);
                tpm_buf_append(&buf, options->blobauth, options->blobauth_len);

-               if (tpm2_chip_auth(chip)) {
+               if (tpm2_chip_auth(chip))
                        tpm_buf_append_hmac_session(chip, &buf, 
TPM2_SA_ENCRYPT, NULL, 0);
-               } else  {
-                       offset = buf.handles * 4 + TPM_HEADER_SIZE;
-                       head = (struct tpm_header *)buf.data;
-                       if (tpm_buf_length(&buf) == offset)
-                               head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
-               }
        }

        rc = tpm_buf_fill_hmac_session(chip, &buf);
--
2.39.5

J.

--
"Never test for an error condition you don't know how to handle."
 --Steinbach