commit 84b59f6487d82d3ab4247a099aba66d4d17e8b08 upstream
When checking whether the response is large enough to be able to contain
the received random bytes in tpm_get_random() and tpm2_get_random(),
they fail to take account the header size, which should be added to the
minimum size. This commit fixes this issue.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: c659af78eb7b ("tpm: Check size of response before accessing data")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
For v4.14 and v4.18. Fixed a merge conflict.
drivers/char/tpm/tpm-interface.c | 3 ++-
drivers/char/tpm/tpm2-cmd.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index e8822b3d10e1..a107ee2466da 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1323,7 +1323,8 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
}
rlength = be32_to_cpu(tpm_cmd.header.out.length);
- if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
+ if (rlength < TPM_HEADER_SIZE +
+ offsetof(struct tpm_getrandom_out, rng_data) +
recd) {
total = -EFAULT;
break;
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index d31b09099216..79b00bc4a7c2 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -371,7 +371,8 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
num_bytes);
rlength = be32_to_cpu(cmd.header.out.length);
- if (rlength < offsetof(struct tpm2_get_random_out, buffer) +
+ if (rlength < TPM_HEADER_SIZE +
+ offsetof(struct tpm2_get_random_out, buffer) +
recd)
return -EFAULT;
memcpy(dest, cmd.params.getrandom_out.buffer, recd);
--
2.19.1
