mei: bus: fix received data size check in NFC fixup

commit 582ab27a063a506ccb55fc48afcc325342a2deba upstream.

NFC version reply size checked against only header size, not against
full message size. That may lead potentially to uninitialized memory access
in version data.

That leads to warnings when version data is accessed:
drivers/misc/mei/bus-fixup.c: warning: '*((void *)&ver+11)' may be used uninitialized in this function [-Wuninitialized]:  => 212:2

Reported in
Build regressions/improvements in v4.9-rc3
https://lkml.org/lkml/2016/10/30/57

Fixes: 59fcd7c63abf (mei: nfc: Initial nfc implementation)
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 020de59..bdc7fcd 100644 (file)
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -151,7 +151,7 @@ static int mei_nfc_if_version(struct mei_cl *cl,
 
        ret = 0;
        bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length);
-       if (bytes_recv < 0 || bytes_recv < sizeof(struct mei_nfc_reply)) {
+       if (bytes_recv < if_version_length) {
                dev_err(bus->dev, "Could not read IF version\n");
                ret = -EIO;
                goto err;

diff --git a/drivers/nfc/mei_phy.c b/drivers/nfc/mei_phy.c
index 83deda4..6f9563a 100644 (file)
--- a/drivers/nfc/mei_phy.c
+++ b/drivers/nfc/mei_phy.c
@@ -133,7 +133,7 @@ static int mei_nfc_if_version(struct nfc_mei_phy *phy)
                return -ENOMEM;
 
        bytes_recv = mei_cldev_recv(phy->cldev, (u8 *)reply, if_version_length);
-       if (bytes_recv < 0 || bytes_recv < sizeof(struct mei_nfc_reply)) {
+       if (bytes_recv < 0 || bytes_recv < if_version_length) {
                pr_err("Could not read IF version\n");
                r = -EIO;
                goto err;