From 2ccbe2cb79f2f74ab739252299b6f9ff27586f2c Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Fri, 22 Jul 2016 15:07:56 +0200 Subject: [PATCH] macsec: limit ICV length to 16 octets IEEE 802.1AE-2006 standard recommends that the ICV element in a MACsec frame should not exceed 16 octets: add MACSEC_STD_ICV_LEN in uapi definitions accordingly, and avoid accepting configurations where the ICV length exceeds the standard value. Leave definition of MACSEC_MAX_ICV_LEN unchanged for backwards compatibility with userspace programs. Fixes: dece8d2b78d1 ("uapi: add MACsec bits") Signed-off-by: Davide Caratti Signed-off-by: David S. Miller --- drivers/net/macsec.c | 4 ++-- include/uapi/linux/if_macsec.h | 2 ++ 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index 0cbb935078da..18cfb46c5911 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -510,7 +510,7 @@ static bool macsec_validate_skb(struct sk_buff *skb, u16 icv_len) } #define MACSEC_NEEDED_HEADROOM (macsec_extra_len(true)) -#define MACSEC_NEEDED_TAILROOM MACSEC_MAX_ICV_LEN +#define MACSEC_NEEDED_TAILROOM MACSEC_STD_ICV_LEN static void macsec_fill_iv(unsigned char *iv, sci_t sci, u32 pn) { @@ -3217,7 +3217,7 @@ static int macsec_validate_attr(struct nlattr *tb[], struct nlattr *data[]) case MACSEC_DEFAULT_CIPHER_ID: case MACSEC_DEFAULT_CIPHER_ALT: if (icv_len < MACSEC_MIN_ICV_LEN || - icv_len > MACSEC_MAX_ICV_LEN) + icv_len > MACSEC_STD_ICV_LEN) return -EINVAL; break; default: diff --git a/include/uapi/linux/if_macsec.h b/include/uapi/linux/if_macsec.h index f7d4831a2cc7..02fc49cb72d8 100644 --- a/include/uapi/linux/if_macsec.h +++ b/include/uapi/linux/if_macsec.h @@ -26,6 +26,8 @@ #define MACSEC_MIN_ICV_LEN 8 #define MACSEC_MAX_ICV_LEN 32 +/* upper limit for ICV length as recommended by IEEE802.1AE-2006 */ +#define MACSEC_STD_ICV_LEN 16 enum macsec_attrs { MACSEC_ATTR_UNSPEC, -- 2.20.1