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authorJerry Snitselaar <jsnitsel@redhat.com>2017-03-11 00:46:04 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-25 13:44:32 (GMT)
commitcc15d340ec6a63aec4b0f68465f79b79add847eb (patch)
treeeb83fe6f6237186c974e482e58d3cbfe71d6ddf4 /drivers/char
parent0c150305212b7afc3c8f90d3fe165ba902cc28f9 (diff)
downloadlinux-cc15d340ec6a63aec4b0f68465f79b79add847eb.tar.xz
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/char')
-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 a7c870a..fa0f668 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -111,8 +111,7 @@ 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);