diff options
Diffstat (limited to 'drivers/char/tpm/tpm2-cmd.c')
| -rw-r--r-- | drivers/char/tpm/tpm2-cmd.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 0cdf892ec2a7..1e856259219e 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -281,6 +281,7 @@ struct tpm2_get_random_out { int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) { struct tpm2_get_random_out *out; + struct tpm_header *head; struct tpm_buf buf; u32 recd; u32 num_bytes = max; @@ -288,6 +289,7 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) int total = 0; int retries = 5; u8 *dest_ptr = dest; + off_t offset; if (!num_bytes || max > TPM_MAX_RNG_DATA) return -EINVAL; @@ -320,7 +322,13 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) goto out; } - out = (struct tpm2_get_random_out *)tpm_buf_parameters(&buf); + head = (struct tpm_header *)buf.data; + offset = TPM_HEADER_SIZE; + /* Skip the parameter size field: */ + if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS) + offset += 4; + + out = (struct tpm2_get_random_out *)&buf.data[offset]; recd = min_t(u32, be16_to_cpu(out->size), num_bytes); if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + |