From eb94ec7a6516cd1dc52c0f63d7c3a274e6337416 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Sun, 30 Nov 2014 18:03:49 +0100 Subject: [PATCH] wusb: replace memset by memzero_explicit Memset on a local variable may be removed when it is called just before the variable goes out of scope. Using memzero_explicit defeats this optimization. A simplified version of the semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // @@ identifier x; type T; @@ { ... when any T x[...]; ... when any when exists - memset + memzero_explicit (x, -0, ...) ... when != x when strict } // This change was suggested by Daniel Borkmann Signed-off-by: Julia Lawall Signed-off-by: Greg Kroah-Hartman --- drivers/usb/wusbcore/dev-sysfs.c | 2 +- drivers/usb/wusbcore/security.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/usb/wusbcore/dev-sysfs.c b/drivers/usb/wusbcore/dev-sysfs.c index 101834576236..415b14002a61 100644 --- a/drivers/usb/wusbcore/dev-sysfs.c +++ b/drivers/usb/wusbcore/dev-sysfs.c @@ -101,7 +101,7 @@ static ssize_t wusb_ck_store(struct device *dev, if (wusbhc == NULL) return -ENODEV; result = wusb_dev_4way_handshake(wusbhc, usb_dev->wusb_dev, &ck); - memset(&ck, 0, sizeof(ck)); + memzero_explicit(&ck, sizeof(ck)); wusbhc_put(wusbhc); return result < 0 ? result : size; } diff --git a/drivers/usb/wusbcore/security.c b/drivers/usb/wusbcore/security.c index cc74d669c802..b66faaf3e842 100644 --- a/drivers/usb/wusbcore/security.c +++ b/drivers/usb/wusbcore/security.c @@ -522,10 +522,10 @@ error_hs3: error_hs2: error_hs1: memset(hs, 0, 3*sizeof(hs[0])); - memset(&keydvt_out, 0, sizeof(keydvt_out)); - memset(&keydvt_in, 0, sizeof(keydvt_in)); - memset(&ccm_n, 0, sizeof(ccm_n)); - memset(mic, 0, sizeof(mic)); + memzero_explicit(&keydvt_out, sizeof(keydvt_out)); + memzero_explicit(&keydvt_in, sizeof(keydvt_in)); + memzero_explicit(&ccm_n, sizeof(ccm_n)); + memzero_explicit(mic, sizeof(mic)); if (result < 0) wusb_dev_set_encryption(usb_dev, 0); error_dev_set_encryption: -- 2.11.0