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authorJerry Snitselaar <jsnitsel@redhat.com>2017-03-10 17:46:04 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-25 14:30:07 +0200
commit63450e38efe3ce80e563827d5b3f59b3f7a12ecf (patch)
tree2454e1ee82e1cd413cfb30aa8635c06f616c8458 /drivers
parent025e33ee387a398a51588834c3172bedf4f9c485 (diff)
tpm_crb: check for bad response size
commit 8569defde8057258835c51ce01a33de82e14b148 upstream. 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 <jsnitsel@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/char/tpm/tpm_crb.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 2b21398c3adc..35308dfff754 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -118,8 +118,7 @@ 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);