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@xxxxxxxxxxxxx>
---
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
