From: Stefan Berger <stefanb@linux.ibm.com>
To: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
jarkko@kernel.org
Cc: Stefan Berger <stefanb@linux.ibm.com>
Subject: [PATCH] tpm: Check for availability of chip->ops before requesting locality
Date: Wed, 7 Jun 2023 12:16:47 -0400 [thread overview]
Message-ID: <20230607161647.3257117-1-stefanb@linux.ibm.com> (raw)
When executing kexec on ppc64 tpm_class_shutdown() is called before
tpm_chip_unregister() and therefore chip->ops is NULL when
tpm_amd_is_rng_defective() is called. Check for chip->ops before
requesting the locality in tpm_amd_is_rng_defective() to avoid a
crash.
Fixes: bd8621ca1510 ("tpm: Add !tpm_amd_is_rng_defective() to the hwrng_unregister() call site")
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
drivers/char/tpm/tpm-chip.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index cd48033b804a..bc1ec1632fd8 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -524,7 +524,7 @@ static bool tpm_amd_is_rng_defective(struct tpm_chip *chip)
u64 version;
int ret;
- if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
+ if (!chip->ops || !(chip->flags & TPM_CHIP_FLAG_TPM2))
return false;
ret = tpm_request_locality(chip);
--
2.39.1
reply other threads:[~2023-06-07 16:17 UTC|newest]
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