From: Julia Lawall <julia@xxxxxxx> 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/) // <smpl> @@ identifier x; type T; @@ { ... when any T x[...]; ... when any when exists - memset + memzero_explicit (x, -0, ...) ... when != x when strict } // </smpl> This change was suggested by Daniel Borkmann <dborkman@xxxxxxxxxx> Signed-off-by: Julia Lawall <julia@xxxxxxx> --- Daniel Borkmann suggested that these patches could go through Herbert Xu's cryptodev tree. 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 1018345..415b140 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 cc74d66..b66faaf 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: -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
