macsec: always read MACSEC_SA_ATTR_PN as a u64

[ Upstream commit c630d1fe6219769049c87d1a6a0e9a6de55328a1 ] Currently, MACSEC_SA_ATTR_PN is handled inconsistently, sometimes as a u32, sometimes forced into a u64 without checking the actual length of the attribute. Instead, we can use nla_get_u64 everywhere, which will read up to 64 bits into a u64, capped by the actual length of the attribute coming from userspace. This fixes several issues: - the check in validate_add_rxsa doesn't work with 32-bit attributes - the checks in validate_add_txsa and validate_upd_sa incorrectly reject X << 32 (with X != 0) Fixes: 48ef50f ("macsec: Netlink support of XPN cipher suites (IEEE 802.1AEbw)") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: qsn

drivers/net/macsec.c

@@ -1696,7 +1696,7 @@ static bool validate_add_rxsa(struct nlattr **attrs)
 return false;
 
 if (attrs[MACSEC_SA_ATTR_PN] &&
- *(u64 *)nla_data(attrs[MACSEC_SA_ATTR_PN]) == 0)
+ nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 return false;
 
 if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
@@ -1939,7 +1939,7 @@ static bool validate_add_txsa(struct nlattr **attrs)
 if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
 return false;
 
-if (nla_get_u32(attrs[MACSEC_SA_ATTR_PN]) == 0)
+if (nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 return false;
 
 if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
@@ -2293,7 +2293,7 @@ static bool validate_upd_sa(struct nlattr **attrs)
 if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
 return false;
 
-if (attrs[MACSEC_SA_ATTR_PN] && nla_get_u32(attrs[MACSEC_SA_ATTR_PN]) == 0)
+if (attrs[MACSEC_SA_ATTR_PN] && nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 return false;
 
 if (attrs[MACSEC_SA_ATTR_ACTIVE]) {