From e8660ded7f5a9889395d33ce3d5e8c729a462bf5 Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Thu, 18 Jan 2018 17:48:18 +0100 Subject: [PATCH] macsec: restore uAPI after addition of GCM-AES-256 Commit ccfdec908922 ("macsec: Add support for GCM-AES-256 cipher suite") changed a few values in the uapi headers for MACsec. Because of existing userspace implementations, we need to preserve the value of MACSEC_DEFAULT_CIPHER_ID. Not doing that resulted in wpa_supplicant segfaults when a secure channel was created using the default cipher. Thus, swap MACSEC_DEFAULT_CIPHER_{ID,ALT} back to their original values. Changing the maximum length of the MACSEC_SA_ATTR_KEY attribute is unnecessary, as the previous value (MACSEC_MAX_KEY_LEN, which was 128B) is large enough to carry 32-bytes keys. This patch reverts MACSEC_MAX_KEY_LEN to 128B and restores the old length check on MACSEC_SA_ATTR_KEY. Fixes: ccfdec908922 ("macsec: Add support for GCM-AES-256 cipher suite") Signed-off-by: Davide Caratti Signed-off-by: Sabrina Dubroca Signed-off-by: David S. Miller --- drivers/net/macsec.c | 12 +++++------- include/uapi/linux/if_macsec.h | 6 +++--- 2 files changed, 8 insertions(+), 10 deletions(-) diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index f522715c6595..7de88b33d5b9 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -396,8 +396,6 @@ static struct macsec_cb *macsec_skb_cb(struct sk_buff *skb) #define MACSEC_GCM_AES_128_SAK_LEN 16 #define MACSEC_GCM_AES_256_SAK_LEN 32 -#define MAX_SAK_LEN MACSEC_GCM_AES_256_SAK_LEN - #define DEFAULT_SAK_LEN MACSEC_GCM_AES_128_SAK_LEN #define DEFAULT_SEND_SCI true #define DEFAULT_ENCRYPT false @@ -1605,7 +1603,7 @@ static const struct nla_policy macsec_genl_sa_policy[NUM_MACSEC_SA_ATTR] = { [MACSEC_SA_ATTR_KEYID] = { .type = NLA_BINARY, .len = MACSEC_KEYID_LEN, }, [MACSEC_SA_ATTR_KEY] = { .type = NLA_BINARY, - .len = MAX_SAK_LEN, }, + .len = MACSEC_MAX_KEY_LEN, }, }; static int parse_sa_config(struct nlattr **attrs, struct nlattr **tb_sa) @@ -2374,7 +2372,7 @@ static int nla_put_secy(struct macsec_secy *secy, struct sk_buff *skb) switch (secy->key_len) { case MACSEC_GCM_AES_128_SAK_LEN: - csid = MACSEC_CIPHER_ID_GCM_AES_128; + csid = MACSEC_DEFAULT_CIPHER_ID; break; case MACSEC_GCM_AES_256_SAK_LEN: csid = MACSEC_CIPHER_ID_GCM_AES_256; @@ -3076,7 +3074,7 @@ static int macsec_changelink_common(struct net_device *dev, if (data[IFLA_MACSEC_CIPHER_SUITE]) { switch (nla_get_u64(data[IFLA_MACSEC_CIPHER_SUITE])) { case MACSEC_CIPHER_ID_GCM_AES_128: - case MACSEC_DEFAULT_CIPHER_ALT: + case MACSEC_DEFAULT_CIPHER_ID: secy->key_len = MACSEC_GCM_AES_128_SAK_LEN; break; case MACSEC_CIPHER_ID_GCM_AES_256: @@ -3355,7 +3353,7 @@ static int macsec_validate_attr(struct nlattr *tb[], struct nlattr *data[], switch (csid) { case MACSEC_CIPHER_ID_GCM_AES_128: case MACSEC_CIPHER_ID_GCM_AES_256: - case MACSEC_DEFAULT_CIPHER_ALT: + case MACSEC_DEFAULT_CIPHER_ID: if (icv_len < MACSEC_MIN_ICV_LEN || icv_len > MACSEC_STD_ICV_LEN) return -EINVAL; @@ -3428,7 +3426,7 @@ static int macsec_fill_info(struct sk_buff *skb, switch (secy->key_len) { case MACSEC_GCM_AES_128_SAK_LEN: - csid = MACSEC_CIPHER_ID_GCM_AES_128; + csid = MACSEC_DEFAULT_CIPHER_ID; break; case MACSEC_GCM_AES_256_SAK_LEN: csid = MACSEC_CIPHER_ID_GCM_AES_256; diff --git a/include/uapi/linux/if_macsec.h b/include/uapi/linux/if_macsec.h index 2e522835a4af..98e4d5d7c45c 100644 --- a/include/uapi/linux/if_macsec.h +++ b/include/uapi/linux/if_macsec.h @@ -18,7 +18,7 @@ #define MACSEC_GENL_NAME "macsec" #define MACSEC_GENL_VERSION 1 -#define MACSEC_MAX_KEY_LEN 256 +#define MACSEC_MAX_KEY_LEN 128 #define MACSEC_KEYID_LEN 16 @@ -26,9 +26,9 @@ #define MACSEC_CIPHER_ID_GCM_AES_128 0x0080C20001000001ULL #define MACSEC_CIPHER_ID_GCM_AES_256 0x0080C20001000002ULL -#define MACSEC_DEFAULT_CIPHER_ID MACSEC_CIPHER_ID_GCM_AES_128 /* deprecated cipher ID for GCM-AES-128 */ -#define MACSEC_DEFAULT_CIPHER_ALT 0x0080020001000001ULL +#define MACSEC_DEFAULT_CIPHER_ID 0x0080020001000001ULL +#define MACSEC_DEFAULT_CIPHER_ALT MACSEC_CIPHER_ID_GCM_AES_128 #define MACSEC_MIN_ICV_LEN 8 #define MACSEC_MAX_ICV_LEN 32