Make sure size of response buffer is at least 6 bytes, or
we will underflow and pass large size_t to memcpy_fromio().
This was encountered while testing earlier version of
locality patchset.
Fixes: 30fc8d138e912 ("tpm: TPM 2.0 CRB Interface")
Signed-off-by: Jerry Snitselaar <jsnit...@redhat.com>
---
drivers/char/tpm/tpm_crb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 89dc8a176ff1..cda4f312d1c9 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -236,7 +236,7 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t
count)
memcpy_fromio(buf, priv->rsp, 6);
expected = be32_to_cpup((__be32 *) &buf[2]);
- if (expected > count)
+ if (expected > count || expected < 6)
return -EIO;
memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);
--
2.11.0.258.ge05806da9
